Table 1 summarizes the estimated risks of bleeding with various endoscopic procedures (1% or more), in settings where the bleeding can be managed endoscopically.

Table 1 The estimated risks of bleeding with various endoscopic procedures

Procedure	Estimated bleeding risk (%)
Colonic polypectomy	1–2.5
Gastric polypectomy or jumbo/snare biopsy	4
Endoscopic mucosal resection	≤22
Ampullectomy	8
Endoscopic sphincterotomy	2.5–5
Photodynamic therapy	≤6
Endoscopic treatment of esophageal or gastric varices	≤6
Endoscopic hemostasis of vascular lesions	≤5

1.2.2 Low risk of bleeding (<1%) in settings where bleeding cannot be monitored endoscopically

• Endoscopic ultrasound-guided FNA

• Percutaneous gastrostomy

• Gastrointestinal stricture dilatation by bougie or balloon dilator. Insertion of a self-expanding metallic stent without dilatation

• Transnasal gastroscopy (risk of epistaxis).

2 Bleeding associated with antithrombotic therapy

2.1 Antiplatelet drugs

These drugs inhibit platelet function, particularly activation and aggregation.

Aspirin and most NSAIDs inhibit platelet aggregation. Aspirin induces irreversible inhibition of cyclooxygenase. Doses usually range from 75 to 325 mg/day (1–2 mg/kg in practice). Disturbance in clotting is not fully corrected until all platelets have been replaced, which takes 7–10 days.

However, a functional platelet level of 50 × 10⁹/L is regarded as adequate for normal hemostatic function. Platelets are renewed at a rate of 10% per day. Thus, depending on the baseline platelet level, discontinuing treatment for 3–5 days is generally sufficient for a patient to recover their normal hemostatic function. NSAIDs also inhibit cyclooxygenase, albeit reversibly. The duration of action is temporary and is determined by the individual drug’s half-life.

The limited data available suggest that standard doses of aspirin and NSAIDs do not significantly increase the risk of bleeding secondary to endoscopic biopsy, colonic snare polypectomy or biliary sphincterotomy. For snare polypectomy, use of a detachable loop is recommended in the presence of a polyp stalk >1 cm. There are no data concerning polyp resection by endoscopic mucosal resection (EMR) or other high-risk procedures in patients on aspirin therapy.

2.1.1 Thienopyridines, dipyridamole, and glycoprotein inhibitors

Thienopyridines (ticlopidine and clopidogrel) irreversibly suppress one of the adenosine diphosphate (ADP) platelet receptors. These preparations frequently prolong the bleeding time, but there is currently no test available for measurement of restoration of normal platelet function. In cases where therapy is suspended, it is recommended that 7–10 days be allowed for platelet renewal. However, as is the case with aspirin, 3–5 days may be sufficient for the return of normal hemostatic function (see above). Platelet transfusion can be beneficial for bleeding management. Ticlopidine has been largely replaced by clopidogrel because of side-effects. There is also little data available on the newer thienopyridine prasugrel. Dipyridamole has only a moderate antiplatelet effect and does not increase the risk of bleeding. Glycoprotein IIb/IIIa inhibitors, abciximab, eptifibatide, and tirofiban, are used parenterally in the short-term management of acute coronary syndromes. Endoscopy in patients receiving these agents would only occur in life-threatening situations and after careful discussion with the patient’s cardiologist, and these drugs are not the subject of this chapter.

2.2 Vitamin K antagonists

Coumarin (warfarin, acenocoumarol) and phenindione are the only oral anticoagulant drugs available today. Their plasma half-lives vary but normal coagulation is usually restored 2–4 days following discontinuation of the drug. The anticoagulation effect achieved depends on the dose used and the patient’s susceptibility to the drug. The International Normalized Ratio (INR) accurately reflects this effect. The risk of bleeding increases as the INR rises, an INR ranging from 2 to 3 is generally needed for effective anticoagulation and carries a low risk of bleeding.

An INR of 3–4.5 is necessary in the presence of a major thromboembolic risk. If the INR is <1.5, the bleeding risk is on a par with that of non-treated patients. In the event of an overdose (INR >6) and/or bleeding, various options are available. In the absence of bleeding, discontinuation of treatment and oral vitamin K intake may be sufficient. In the presence of major bleeding, intravenous vitamin K (5–10 mg) along with IV prothrombin complex, 30–50 units/kg or fresh frozen plasma should be considered. For minor bleeding, smaller doses of IV vitamin K should be given, e.g. 0.5–2.5 mg.

Warning!

Giving large doses of vitamin K can make it difficult to re-establish anticoagulation with warfarin after the bleeding episode is resolved. Discuss with Hematology and the patient’s cardiologist/specialist before giving IV vitamin K.

2.3 Heparins

Heparins are the third family of antithrombotics that are widely used. The main indications for heparins are prophylaxis and therapy of venous thromboembolic disease, including deep venous thrombosis (DVT), pulmonary embolism, acute coronary syndromes, and thrombosis prophylaxis in patients with mechanical cardiac valve prostheses before switching to oral anticoagulation. Only low-molecular weight heparins (LMWHs) are used for DVT prophylaxis, in doses ranging from 2000 to 5000 U once daily according to the thrombosis risk level and the product used. The bleeding risk with these doses is low, becoming negligible 12 hour following administration. For other indications, either subcutaneous LMWHs or unfractionated heparin administered intravenously is used.

The LMWH doses in such settings vary considerably depending on the preparation used and body weight. If a LMWH is administered twice daily, it is necessary to wait 12–18 hour for the heparin level to return to a level that allows normal hemostasis. If the drug is administered once daily, 24 hour must be allowed. It should be noted that the activated partial thromboplastin time (APTT) is not useful in such cases as it remains normal, even in the presence of persistent heparinemia. The only way to verify the presence of residual heparinemia is the anti-Xa activity level, which should be <0.20 U/mL. The half-life for unfractionated heparin administered intravenously at a dose of 400–600 U/kg per day is 45–90 minutes and normal hemostasis returns 4–6 hour after the infusion ends. In these cases, the APTT may be useful for verifying that clotting has normalized. If unfractionated heparin is administered via two or three injections using the same dose, because of the longer half-life, it is necessary to wait 8–12 hour for normal coagulation to return. Here too the APTT may allow verification of this.

2.4 New antithrombotics

New antithrombotics are becoming available: an anti-Xa preparation known as fondaparinux (Arixtra) is available and is used for prophylaxis of deep venous thrombosis following orthopedic surgery. The bleeding risk is about the same as with LMWHs but there is no known antidote in the event of bleeding. Fondaparinux has a half-life of 15 hour and endoscopy should not be performed until the drug has been completely eliminated, which takes 4–5 half-lives.

3 Risks associated with discontinuation of antithrombotic therapy

The risk associated with discontinuation of antithrombotic therapy ranges from minor to major, depending on the specific indications involved. Cases of sudden death or coronary stent occlusion within 7 days of discontinuation have been described.

3.1 Patients receiving oral anticoagulants

3.1.1 Indications associated with acute thromboembolic risk (Table 2)

When taking a patient off warfarin, it is essential to use a specific protocol (Box 2) involving unfractionated heparin. It is also advisable to carefully weigh whether the planned procedure is truly indicated, and if so, undertake procedures associated with a low risk of bleeding (e.g. insertion of a biliary stent without sphincterotomy).

Table 2 Conditions associated with acute thromboembolic risk during interruption of antithrombotic therapy

Condition	Target INR
All prosthetic metal valves in a mitral position	3–4.5
All first-generation metal aortic valves	3–4.5
Second-generation aortic valves in patients with an additional embolic risk factor	3–4.5
Atrial fibrillation associated with other thromboembolic risk factors, particularly mitral valve disease	2–3

Box 2 Patients receiving warfarin

Switching medications in patients with acute thromboembolic risk

• Discontinuation of warfarin 3–5 days prior to the procedure.

• The day after discontinuation, begin an anticoagulant dose of heparin; monitor the patient’s APTT.

• Check INR the day before the examination.

• Discontinue unfractionated IV heparin 4–6 hour prior to endoscopy or the final injection of LMWH 8 hour (three injections/day) or 12 hour before the procedure (two injections/day); resume heparin 6–8 hour post-procedure or immediately if there is no risk of bleeding.

• Resume warfarin the same evening (or later, see above).

• Discontinue heparin once two daily INR results are satisfactory.

Switch to unfractionated heparin (or, in some countries, LMWH): same as for acute thromboembolic risk.

• Discontinue warfarin 3–5 days before the procedure.

• Begin therapeutic doses of LMWH the following day.

• Discontinue LMWH on the day before the procedure and check the INR and platelets.

• Resume LMWH 12 hour post-procedure.

• Resume warfarin the same evening (or later, see above).

• Discontinue LMWH if two INR results 2 days apart are between 2 and 3.

Taking patients off warfarin is usually undertaken using therapeutic doses of IV unfractionated heparin (400–600 IU/kg per 24 hour), which remains the reference method.

3.1.2 Indications associated with low or moderate thromboembolic risk (Box 3)

Box 3 Indications associated with low or moderate thromboembolic risk

• Coronary syndromes and/or DVT management.

• Atrial fibrillation in patients over 65 years or with associated thromboembolic risk factors (history of CVA, cardiac failure <2 months previously or left ventricular dilatation with end diastolic dimension >60 mm).

• Some cases of mitral regurgitation or stenosis (with a dilated left-atrium).

• Mechanical aortic valves in the absence of embolic risk factors.

Temporary discontinuation of antithrombotic therapy is usually sufficient in these situations.

3.2 Patients receiving antiplatelet drugs

3.2.1 Indications associated with acute thromboembolic risk (Box 4)

Box 4 Patients receiving antiplatelet drugs

4 Switching from warfarin or antiplatelet drugs to alternative therapy

No drug has been approved for switching from warfarin or antiplatelet therapy. The discontinuation/switching procedure takes account of the treatment currently being used and the patient’s thromboembolic risk factors (Boxes 2 and 4).

Calcium heparin may also be effective. The total required dose per 24 hour (in units) is the same as or slightly higher than the dose needed for continuous infusion. The drug can be administered by two or three daily subcutaneous injections. The efficacy of therapy is assessed by the APTT. The target APTT ratio should be 2–3. If heparin levels are measured to guide results, they should be between 0.3 and 0.6 IU/L. If there is a discrepancy between the unfractionated heparin dose injected and the resulting APTT results, measurement of circulating heparin levels is recommended.

The efficacy of switching to LMWH has been validated but guidelines may vary from country to country and local practice needs to be clarified and followed. If LMWHs are used, the dose must be adjusted to the patient’s weight and should be given by one or two subcutaneous daily injections.

Warning!

Heparin-induced thrombocytopenia with or without thrombosis (HITT) is a rare but serious complication of treatment with either unfractionated heparin or LMWHs and should be suspected if the platelet count drops by 50% or more. If this occurs, all heparins should be stopped and an alternative thrombin inhibitor (e.g. danaparoid) used.

A patient can be taken off antiplatelet drugs using preparations with short-term and reversible anti-thrombotic action. However, no treatment of this kind has been validated prospectively.

LMWHs are an alternative and are administered using the same protocol as for switching to warfarin.

5 Resumption of antithrombotic treatment

While most bleeding occurs within 24 hour postoperatively, it can also be delayed (for up to 3 weeks following polypectomy). Starting the patient on antithrombotic therapy too soon can provoke delayed bleeding. Following a sphincterotomy, the risk of bleeding is put at 10–15% if warfarin is resumed before the third post-procedure day. There is little hard data to guide when to resume antithrombotic therapy and each case must be decided on its individual merits.

6 Recommendations

6.1 General recommendations

Clinical Tip

In cases where antithrombotic therapy is temporary and an endoscopic procedure would carry a high risk of bleeding and is not urgent, the procedure should be postponed.

Clinical Tip

In an emergency setting or if antithrombotic therapy was not discontinued and/or is scheduled to resume at an early stage, the following, which reduce the risk of bleeding, should be used wherever possible: detachable loops; hemostatic clips; pancreatic or biliary stents without a sphincterotomy.

All equipment needed for endoscopic hemostasis should be ready to hand. Use of drugs or blood products that inhibit antithrombotic action should also be considered in light of the endoscopic alternatives and the relative thromboembolic risk.

Warning!

If an emergency situation does not allow for determination of a patient’s thromboembolic risk, as a precaution the patient should be regarded as high risk.

6.2 Setting-specific therapy adjustments

6.2.1 High-risk procedures

Elevated risk of bleeding (1% or more), if the patient can be treated endoscopically (Table 3):

• In the absence of any other hemostatic abnormality, colonoscopy with snare polypectomy and sphincterotomy can be performed without stopping standard-dose aspirin or NSAIDs. A detachable loop should be used for colonic polypectomies if the stalk diameter is >1 cm. Mucosectomy (EMR) should not be performed while the patient is taking aspirin.

• Apart from these special situations, antithrombotics should be discontinued pre-procedure, for as long as necessary to deactivate them. For warfarin, confirmation that the INR has normalized should be sought.

Table 3 Setting-specific therapy adjustments

Low risk of bleeding (<1%) in patients who cannot be monitored endoscopically:

• All antithrombotics should be discontinued prior to the procedure, for as long as necessary to deactivate them.

• For warfarin, again the INR needs to be checked pre-procedure.

6.2.2 Low-risk procedures

No adjustment of anticoagulant or antiplatelet therapy is necessary. For warfarin, a recent verification of the INR is advisable. Non-urgent procedures should be postponed if anticoagulation is outside the therapeutic range.

6.3 Treatment discontinuation and resumption

Anticoagulant treatment should be discontinued in accordance with the patient’s thromboembolic risk, as follows:

• In patients at high risk During the discontinuation period, the patient is put on a suitable antithrombotic and monitored.

• In patients at moderate risk During the discontinuation period, the possibility of putting the patient on a suitable antithrombotic is considered; the patient is monitored if an antithrombotic is administered.

• In patients at low risk No discontinuation of therapy is necessary.

Antithrombotic therapy is resumed post-procedure. In view of the risk of delayed bleeding, the benefits of immediate resumption of antithrombotic therapy should be weighed against the increased risk of bleeding and each case must be considered on its own merits.

Conclusion

It is difficult to formulate recommendations that will cover all possible clinical scenarios that endoscopists will encounter. The bleeding risk associated with the procedure and the underlying pathology (thromboembolic risk) must be assessed on a case-by-case basis. Clear communication between the endoscopist and the prescribing physician is important in deciding the best strategy. The guidance provided in this chapter can potentially serve as a basis for such discussions but it should be borne in mind that this consensus is somewhat arbitrary in places because of lack of an evidence base for recommendations and also because guidelines differ from country to country. The British Society of Gastroenterology guidelines, for example, include a simple, practical flowchart that is a useful starting point for many of the common clinical situations (Fig. 1).

Figure 1 Guidelines for the management of patients on warfarin or clopidogrel undergoing endoscopic procedures (AF, atrial fibrillation; EMR, endoscopic mucosal resection; ERCP, endoscopic retrograde cholangiopancreatography; EUS, endoscopic ultrasound; FNA, fine needle aspiration; INR, international normalized ratio; LMWH, low molecular weight heparin; PEG, percutaneous endoscopic gastroenterostomy; VTE, venous thromboembolism)

(With permission from Vietch AM et al. Guidelines for the management of anticoagulant and antiplatelet therapy in patients undergoing endoscopic procedures. Gut 2008; 57: 1322–1329.)

Further Reading

American Society of Gastrointestinal Endoscopy. Management of antithrombotic agents for endoscopic procedures. Gastrointest Endosc. 2009;70:1060-1070.

Boustière C, Veitch A, Vanbiervliet, et al. Endoscopy and antiplatelet agents. European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy. 2011;43(5):445-461.

Hui AJ, Wong RM, Ching JY, et al. Risk of colonoscopy polypectomy bleeding with anticoagulants and antiplatelet agents: analysis of 1657 cases. Gastrointest Endosc. 2004;59:44-48.

Patrono C, Coller B, Dalen JE, et al. Platelet-active drugs: the relationships among dose, effectiveness, and optimal therapeutic range. Chest. 2001;119(1 Suppl):39S-63S.

Samama CM, Djoudi R, Lecompte T, et alAFSSAPS Expert Group. Perioperative platelet transfusion: recommendations of the Agence française de sécurité sanitaire des produits de santé (AFSSAPS)] 2003. and the. Can J Anesth. 2005;52:30-37.

Stein PD, Alpert JS, Bussey HI, et al. Antithrombotic therapy in patients with mechanical and biological prosthetic heart valves. Chest. 2001;119(1 Suppl):220S-227S.

Veitch AM, Baglin TP, Gershlick SH, et al. Guidelines for the management of anticoagulant and antiplatelet therapy in patients undergoing endoscopic procedures. Gut. 2008;57:1322-1329.

Yousfi M, Gostout CJ, Baron TH, et al. Postpolypectomy lower gastrointestinal bleeding: potential role of aspirin. Am J Gastroenterol. 2004;99(9):1785-1789.

Zuckerman MJ, Hirota WK, Adler DG, et al. ASGE guideline: the management of low-molecular-weight heparin and nonaspirin antiplatelet agents for endoscopic procedures. Gastrointest Endosc. 2005;61:189-194.

2.2 Antibiotic prophylaxis

Anne Marie Lennon

Summary

Introduction 59

1. Antibiotics for the prevention of infective endocarditis 59

2. Antibiotic prophylaxis in specific groups of patients 60

3. Antibiotic prophylaxis for specific endoscopic procedures 60

Key Points

• Prophylactic antibiotics are no longer recommended purely as prophylaxis against infective endocarditis.

• Patients with cirrhosis who present with an upper GI bleed should be given prophylactic antibiotics.

• Patients who have biliary obstruction with sepsis, or who have biliary obstruction which remains undrained following ERCP, should remain on antibiotics until the biliary obstruction is relieved.

• Patients who undergo a EUS-FNA of a cystic lesion should be given prophylactic antibiotics.

• All patients who have a PEG inserted should have pre-procedure antibiotics.

• Patients undergoing EUS or ERCP drainage of a pseudocyst require prophylactic antibiotics.

Introduction

Previously, antibiotics have been prescribed for three indications associated with endoscopic procedures:

• To prevent infective endocarditis in patients with heart disease

• To treat patients with infection prior to endoscopy (e.g. ascending cholangitis)

• As prophylaxis against infection following an endoscopic procedure.

European and American Society guidelines (Table 1) have recently changed significantly with respect to antibiotic prophylaxis against infective endocarditis. Antibiotics are no longer recommended for gastrointestinal procedures in the absence of established infection, but are still recommended for patients with evidence of infection prior to endoscopy and in patients undergoing specific procedures, which are discussed below.

Table 1 Specific society recommendations for prophylaxis of infective endocarditis in high risk patients

Society	Recommendation	Further Reading
AHA 2007	Prophylaxis against infective endocarditis is not recommended for non-dental procedures such as transesophageal echocardiogram, EGD or colonoscopy in the absence of active infection.	Wilson et al 2007; Nishimura et al 2008
NICE 2008	Antibiotic prophylaxis for gastrointestinal procedures is not recommended.	Richey et al 2008
ESC	Antibiotic prophylaxis is not recommended for gastroscopy, colonoscopy, or transesophageal echocardiography.	Habib et al 2009
BSG	Antibiotics are not indicated as prophylaxis against infective endocarditis.	Allison et al 2009
ASGE	Antibiotic prophylaxis for infectious endocarditis is not recommended.	Banerjee et al 2008

AHA, American Heart Association; NICE, National Institute for Heath and Clinical Excellence; ESC, European Society of Cardiology; BSG, British Society of Gastroenterology; ASGE, American Society of Gastrointestinal Endoscopy.

Note

• It is important to have knowledge of local antibiotic resistance.

• Society guidelines for antibiotic prophylaxis vary. Ensure that you are aware of your own local guidelines.

1 Antibiotics for the prevention of infective endocarditis

European and American societies have recently significantly altered their recommendations for endocarditis prophylaxis in patients undergoing endoscopy (see Further Reading). The rationale for these changes has been summarized by the European Society of Cardiology:

• The incidence of bacteremia after endoscopic procedures versus the risk of bacteremia associated with routine daily activities.

The incidence of transient bacteremia varies greatly in studies. Transient bacteremia occurs frequently in daily routine activities such as brushing teeth, flossing or chewing. It therefore appears that a large proportion of cases of infective endocarditis arise from these daily activities and are not procedure related.

• Risks and benefits of prophylaxis:

The procedure-related risk of a patient developing infective endocarditis ranges from 1 : 14 000 000 for dental procedures in the average population to 1 : 95 000 for patients with previous infectious endocarditis. These estimates demonstrate the huge number of patients that require treatment to prevent a single case of infective endocarditis.

In the majority of patients, no procedure preceded the development of infective endocarditis. Therefore, infective endocarditis prophylaxis may at best protect a small proportion of patients, while the bacteremia that causes infective endocarditis in the majority of patients appears to derive from another source.

Antibiotic administration carries a small risk of anaphylaxis.

Widespread or inappropriate use of antibiotics can lead to resistant microorganisms.

• Lack of scientific evidence for the efficacy of infective endocarditis prophylaxis:

Studies reporting on the efficacy of antibiotic prophylaxis to prevent or alter bacteremia are contradictory, with no data demonstrating that reduced duration or frequency of bacteremia after any medical procedure leads to a reduced procedure-related risk of infective endocarditis.

The efficacy of antibiotic prophylaxis itself has never been investigated in a prospective randomized controlled trial and assumptions of efficacy are based on non-uniform expert opinion, animal experiments, case reports and contradictory observational studies.

Note

All societies recommend that in patients with an established infection prior to endoscopy, or in patients undergoing a procedure which will require antibiotics (see below), antibiotic coverage for enterococci should be given (i.e. amoxicillin, ampicillin, piperacillin or vancomycin) in addition to the antibiotics for the specific indication.

2 Antibiotic prophylaxis in specific groups of patients

The guidelines of the American Society of Gastrointestinal Endoscopy can be found in Table 2.

Table 2 American Society of Gastrointestinal Endoscopy guidelines

2.1 Severe immunosuppression

Some societies (British Society of Gastroenterology) recommend antibiotic prophylaxis for patients with severe neutropenia (<0.5 × 10⁹/L) and/or advanced hematological malignancy who undergo endoscopic procedures that are known to be associated with a high risk of bacteremia.

2.2 Vascular grafts or prostheses

Antibiotic prophylaxis is not recommended for patients with vascular grafts or prostheses.

2.3 Patients with cirrhosis or portal hypertension

Patients with portal hypertension and ascites have an increased risk of bacteremia in the presence of an upper gastrointestinal bleed, while sclerotherapy is also associated with high rates of bacteremia. Patients with cirrhosis and bacterial infection have an increased risk of re-bleeding, and poor outcomes, while patients who receive antibiotic prophylaxis may have a reduced risk of variceal re-bleeding. A meta-analysis has shown that antibiotic prophylaxis in patients with variceal bleeding is associated with improved short-term survival.

Recommendation for patients with cirrhosis and upper GI bleeding:

• All patients with cirrhosis who present with an upper gastrointestinal bleed should be given prophylactic antibiotics.

3 Antibiotic prophylaxis for specific endoscopic procedures

See Table 3 for recommended antibiotics based on the British Society of Gastroenterology guidelines.

Procedure	Antibiotic coverage
ERCP	Ciprofloxacin 750 mg PO 90 min pre-procedure
	or
	Gentamicin 1.5 mg/kg IV
OLT undergoing ERCP	Ciprofloxacin 750 mg 90 min pre-procedure
	or
	Gentamicin 1.5 mg/kg IV
	PLUS
	Amoxicillin 1 g IV or vancomycin 20 mg/kg IV infused over at least one hour
EUS FNA cystic lesion	Co-amoxiclav 1.2 g IV
	or
	Ciprofloxacin 750 mg PO 90 min pre-procedure
	3–5 day course of antibiotics post-procedure is usually given
	Antibiotics should be given prior to performing EUS-FNA
PEG	Co-amoxiclav 1.2 g IV
	or
	Second or third generation cephalosporin (i.e. cefuroxime 750 mg IV)
	Teicoplanin 400 mg IV can be used in patients who are penicillin allergic
	Antibiotics should be given prior to commencing the procedure
Cirrhosis with upper-GI bleed	Piperacillin/tazobactam 4.5 g IV three times per day
	or
	Third generation cephalosporin (i.e. cefotaxime 2 g IV three times per day)

PEG, percutaneous endoscopic gastrostomy; ERCP, endoscopic retrograde cholangiopancreatogram; OLT, orthotopic liver transplant; EUS, endoscopic ultrasound; FNA, fine needle aspiration biopsy.

^a Based on British Society of Gastroenterology guidelines. Oral antibiotics should be given 60–90 min pre-procedure to allow absorption of the drug.

3.1 ERCP

Sepsis and cholangitis occur in 0.5–3% of ERCP procedures; however, a meta-analysis of five randomized, placebo-controlled trials failed to demonstrate a decrease in the incidence of cholangitis or sepsis with prophylactic antibiotic use. The exception to this rule is patients with incomplete biliary drainage, who have a high risk of sepsis. These patients should be given antibiotic coverage until adequate drainage is achieved. Patients with pancreatic pseudocysts are also at increased risk of infection, and should receive antibiotic cover.

Recommendations for patients undergoing ERCP:

• Patients with biliary sepsis should be given appropriate antibiotics.

• Patients with biliary obstruction with no evidence of infection do not require antibiotics, unless there is inadequate biliary drainage.

• Patients with undrained biliary systems following ERCP (cholangiocarcinoma, primary sclerosing cholangitis with failed drainage procedure) are at high risk of ascending cholangitis and sepsis and should receive antibiotic cover until adequate drainage is achieved.

• Patients with pancreatic pseudocysts are at increased risk of infection within the pseudocyst. Those patients undergoing an interventional endoscopic procedure (ERCP or EUS) should be given prophylactic antibiotics.

• Some societies (BSG) recommend antibiotic prophylaxis for patients with an orthotopic liver transplant (OLT) who undergo an ERCP.

3.2 EUS

The risk of infection after EUS-FNA of a solid lesion is very low (0.4%). These patients do not require antibiotic prophylaxis. There is an increased risk of infection when samples are acquired from cystic lesions. Therefore, patients undergoing endoscopic fine-needle aspiration (EUS-FNA) of cysts should receive peri-procedural antibiotics. Most endoscopists also continue oral antibiotics for 3–5 days. There is insufficient evidence to recommend antibiotics following EUS-FNA of a solid lesion in the lower gastrointestional tract. The choice of whether or not to give antibiotics should be made on a case by case basis.

Recommendations for patients undergoing EUS:

• Patients undergoing EUS-FNA of a cystic lesion, should have prophylactic antibiotics.

• Prophylactic antibiotics are not required for EUS-FNA of solid lesions.

• Patients undergoing pancreatic pseudocyst drainage should have prophylactic antibiotics.

3.3 PEG

A large number of studies, including two meta-analyses, have shown that antibiotic prophylaxis is effective at reducing wound infection rates using a single dose of an appropriate antibiotic. PEG insertion is associated with a high risk of peristomal wound infection and patients should be given antibiotic prophylaxis.

Recommendations for patients undergoing PEG:

• Patients undergoing PEG insertion should receive antibiotic prophylaxis.

Further Reading

Allison MC, Sandoe JA, Tighe R, et al. Antibiotic prophylaxis in gastrointestinal endoscopy. Gut. 2009;58:869-880.

(Guidelines of the British Society of Gastroenterology)

Banerjee S, Shen B, Baron TH, et al. Antibiotic prophylaxis for GI endoscopy. Gastrointest Endosc. 2008;67:791-798.

(Guidelines of the American Society of Gastrointestinal Endoscopy)

Danchin N, Duval X, Leport C. Prophylaxis of infective endocarditis: French recommendation v2002. Heart. 2005;91:715-718.

(French Guidelines)

Habib G, Hoen B, Tornos P, et al. Guidelines on the prevention, diagnosis, and treatment of infective endocarditis. The task force on the prevention, diagnosis, and the treatment of infective endocarditis of the European Society of Cardiology. Eur Heart J. 2009;30:2369-2413.

Nishimura RA, Carabello BA, Faxon DP, et al. ACC/AHA 2008 Guideline update on valvular heart disease: focused update on infective endocarditis. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. Circulation. 2008;118:887-896.

(Guidelines from the American College of Cardiology and American Heart Association)

Richey R, Wray D, Stokes T. Prophylaxis against infective endocarditis: summary of NICE guidance. BMJ. 2008;336:770-771.

(NICE Guidelines)

Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis. Guidelines from the American Heart Association. Circulation. 2007;116:1736-1754.

(Guidelines of the American Heart Association)

2.3 Sedation

Anne Marie Lennon, Jean-Christophe Létard, Jean Marc Canard

Summary

Introduction 63

1. Pre-procedure assessment 63

2. Monitoring and equipment 64

3. Drugs 66

4. Management of the complications of sedation 70

5. Recovery and discharge 71

Key Points

• The endoscopist is ultimately responsible for sedation of a patient.

• Dose reduction is often required in the elderly or in those with renal, respiratory or hepatic impairment.

• Pre-procedure evaluation allows for assessment of sedation risk.

• Anesthetic input should be considered for patients who are ASA III or above.

• All patients should have continuous monitoring before, during, and after the procedure as standard. Visual monitoring, as well as device monitoring, is important.

• There are four levels of sedation. Most endoscopic procedures are usually undertaken under conscious sedation, although deep sedation can be obtained with propofol.

• It is essential that a member of the sedation team is capable of establishing an airway and providing positive pressure ventilation.

Introduction

Sedation is defined as a drug-induced depression. There are four levels of sedation, ranging from minimal sedation to general anesthesia (Table 1). The majority of endoscopic procedures are performed under conscious sedation, which is also known as moderate sedation. The aim of sedation is to improve patient comfort. This in turn means that the patient moves less, allowing a better assessment of the endoscopic problem. This is particularly useful where a difficult or prolonged procedure is undertaken.

Table 1 Levels of sedation

There is clear variation in sedation practice in different countries, with almost all procedures undertaken in some countries under propofol sedation administered by anesthetists, while in other countries, many upper endoscopies are performed with only topical anesthesia. For any gastroenterologist involved in sedation, it is essential to have a clear understanding of the drugs used in sedation, their side-effects and how to deal with these when they occur, as it is estimated that sedation related complications account for 40–50% of endoscopy-related serious adverse events. The information given in this chapter is the authors’ approach to sedation, and it is important to check local guidelines.

1 Pre-procedure assessment

Patients should be sent general information and instructions prior to the procedure, with clear instruction about medications, fasting and colonic preparation if appropriate.

Box 1

• General information for patients, see Chapter 1.8.

• Management of patients on anticoagulants, see Chapter 2.1.

1.1 Inpatient versus outpatient sedation

Patients who are suitable for outpatient sedation are as follows:

• Must live within 1 hour’s drive of the institution

• Must be monitored by a competent friend or relative during the night following discharge

• The patient must have a telephone.

Patients who do not fulfill these criteria should be admitted overnight.

1.2 Pre-sedation assessment

All patients should be assessed prior to sedation. The aim of this assessment is to identify aspects of the patient’s history and examination that could adversely affect endoscopic sedation. A brief history and examination are required, including airway assessment and determining ASA status (see Tables 2 and 3).

Table 3 American Society of Anesthesiology (ASA) co-morbidity status

ASA class	Description
I	The patient is normal and healthy.
II	The patient has mild systemic disease that does not limit their activities (e.g. controlled diabetes or hypertension without systemic sequelae).
III	The patient has moderate or severe systemic disease, which does limit their activities (e.g. stable angina or diabetes with systemic sequelae).
IV	The patient has a severe systemic disease that is a constant potential threat to life (i.e. decompensated heart failure, end-stage renal failure).
V	The patient is morbid and is at substantial risk of death within 24 hour.

Table 2 History and examination assessment prior to sedation

History	Physical examination
Significant cardiac or pulmonary disease. Neurological or seizure disorder. Stridor, snoring, or sleep apnea ^a. Advanced rheumatoid arthritis ^a. Previous problems with sedation or anesthesia. Chromosomal abnormality (e.g. trisomy 21)^a. Current medications, drug and food allergies. Alcohol or drug abuse. Time of last oral intake ^b. ASA status ^c.	Vital signs and weight. Body habitus – significant obesity, especially involving the neck and facial structures ^a. Auscultation of heart and lungs. Baseline level of consciousness. Assessment of airway ^d (see Cohen et al 2007 for detailed guidelines).

^a These patients are more likely to have a difficult airway.

^b ASA guidelines state that patients should fast a minimum of 2 hour for clear liquids and 6 hour for light meal before sedation.

^c See Table 1 for ASA status.

^d The following physical factors can be associated with difficult airway management: obesity, short neck, limited neck extension, hyoid-mental distance <3 cm in adult), neck mass, cervical spine disease or trauma, tracheal deviation, dysmorphic facial features (e.g. Pierre–Robin syndrome), inability to open mouth >3 cm, edentulous, protruding incisors, loose teeth, macroglossia, tonsillar hypertrophy, nonvisible uvula, micrognathia, retrognathia, trismus, significant malocclusion.

Pregnant patients should be advised of the risks of sedation and the procedure deferred if possible (see ASGE Guidelines 2003 for detailed information).

1.3 Which patients should be referred for anesthetic input?

Anesthetic input should be considered for the following patients:

• Increased risk for complication because of severe co-morbidity (ASA class III or greater)

• Emergency endoscopic procedures

• Prolonged or therapeutic endoscopic procedures requiring deep sedation (e.g. EMR/ESD, pseudocyst drainage, plication of cardioesophageal junction, difficult ERCP)

• Patients with a history of: adverse reaction to sedation/alcohol or drug abuse/inadequate response to moderate sedation/delirious or uncooperative/pregnant/neuromuscular disorders (e.g. myasthenia gravis)/morbid obesity

• Patients in whom airway management may be difficult (see Cohen et al 2007 for detailed guidelines).

2 Monitoring and equipment

Patients undergoing endoscopic procedures should have continuous monitoring (both visual and devices) before, during, and after the procedure. A nurse or assistant should be present throughout the procedure. It is important that they have an understanding of the stages of sedation, monitoring, interpretation of physiologic parameters, and can initiate appropriate intervention in the event of a complication. One member of the team must be able to provide advanced cardiac life support, establish an airway and provide positive pressure ventilation if required. Emergency equipment that should be available at all times in an endoscopy unit is listed in Box 3.

Box 3

Emergency resuscitative equipment

• Assorted syringes, tourniquets, adhesive tape.

• Advanced airway management equipment:

Laryngoscope handles and blades ^a (tested)

Endotracheal tubes and stylets ^a

Laryngeal mask airway ^a.

• Cardiac equipment:

Pulse oximeter

Cardiac defibrillator.

• Pharmacologic antagonists:

Naloxone

Flumazenil.

• Emergency medications ^b :

^a All appropriate sizes should be available.

^b The American Society of Anesthesiologists also suggest having nitroglycerin, amiodarone, methylprednisolone, dexamethasone, diazepam or midazolam (American Society of Anesthesiologists 2002).

Modified from Cohen LB, Deluge MH, Isenberg J et al. AGA Institute review of endoscopic sedation. Gastroenterology 2007; 133:675–701.

Note

Visual, as well as device monitoring, is important.

2.1 Personnel and emergency equipment

A nurse or assistant with appropriate training should be present throughout the procedure. They should have a thorough understanding of the stages of sedation, monitoring, and interpretation of physiologic parameters, as well as the skills to initiate appropriate intervention in the event of a complication. One member of the team must be certified in advanced cardiac life support and be capable of establishing an airway and providing positive pressure ventilation. Emergency equipment (see Box 3) must be available at all times. AGA guidelines suggest that in moderate sedation, the assistant may perform short, interruptible tasks; however, in deep sedation, their only role is observation and monitoring of the patient (Riphaus et al 2009).

2.2 Assessment of level of consciousness

The patient’s level of sedation should be documented prior to commencing sedation, during the procedure and until discharge. There are four different stages of sedation (Table 1) from minimal to general anesthesia. A combination of a benzodiazepine and an opioid is often used to provide conscious sedation, while propofol is used for deep sedation. The level of sedation required for a procedure depends on patient factors such as co-morbidity and anxiety levels, as well as procedural factors such as the complexity of the procedure and discomfort it will generate (i.e. esophageal dilatation). Usually, conscious sedation is sufficient for diagnostic upper endoscopy and colonoscopy, while deeper sedation is required for EUS and ERCP.

2.3 Hemodynamic monitoring

All patients receiving sedation should be monitored for heart rate and blood pressure. Baseline blood pressure should be checked prior to commencing the procedure, and repeated every 3–5 minutes throughout the procedure. Consider cardiac monitoring (ECG) in high-risk patients (e.g. significant cardiovascular disease or dysrhythmia).

2.4 Pulse oximetry

Pulse oximetry should be used in all patients undergoing sedation. Supplemental oxygen delays the detection of hypoventilation, thus it is important to also monitor the patient’s respiratory effort.

2.5 Capnography

Capnography assesses respiratory function by measuring carbon dioxide non-invasively and is more sensitive than either visual observation or pulse oximetry for detecting changes in respiratory function. Capnography should not be used routinely but should be considered in patients undergoing deep sedation or where a patient’s ventilation cannot be observed directly during moderate sedation.

2.6 BIS monitoring

BIS is a non-invasive method of assessing a patient’s level of consciousness by monitoring electroencephalographic activity. It is not currently recommended for use in moderate sedation.

2.7 Supplemental oxygen

Supplemental oxygen should be considered for all patients undergoing moderate or deep sedation.

2.8 Intravenous access

Intravenous access should be maintained through the procedure until the patient is no longer at risk of cardio-respiratory depression.

3 Drugs

There are several different classes of drugs commonly used in endoscopy for sedation, including, benzodiazepines, opioids and the anesthetic agent propofol. The choice of which drug to use depends on patient factors such as anxiety, co-morbidity and age, as well the properties of the drug, such as whether sedative, anxiolytic or amnesic properties are required. Regardless of which drug or combination of drugs is used, there are several key points to remember:

• Wait an appropriate time before giving additional doses of medications to avoid excessive sedation and increased side-effects

• Decrease the dose in the elderly

• Use lower doses when combining two drugs.

The most commonly used drugs are discussed below, followed by their reversal agent (Note: there is no reversal agent for propofol!). The commonest side-effects have been listed for each drug, while a complete list of side-effects associated with each drug can be found at: www.sedationfacts.org. FDA categories (Table 4) have been given for each drug for use in pregnancy. A detailed discussion of the use of sedation medications in pregnant or lactating women can be found in Guidelines for Endoscopy in Pregnant and Lactating Women, Gastrointest Endosc, 2005.

Table 4 FDA categorization of drugs for use in pregnancy

Category	Description
A	Adequate, well-controlled studies in pregnant women have not shown an increased risk of fetal abnormalities.
B	Animal studies have revealed no evidence of harm to the fetus; however, there are no adequate and well-controlled studies in pregnant women, or,
B	Animal studies have shown an adverse effect, but adequate and well-controlled studies in pregnant women have failed to demonstrate a risk to the fetus.
C	Animal studies have shown an adverse effect and there are no adequate and well-controlled studies in pregnant women, or,
C	No animal studies have been conducted and there are no adequate and well-controlled studies in pregnant women.
D	Adequate well-controlled or observational studies in pregnant women have demonstrated a risk to the fetus; however, the benefits of therapy may outweigh the potential risk.
X	Adequate well-controlled or observational studies in animals or pregnant women have demonstrated positive evidence of fetal abnormalities; use of the product is contraindicated in women who are or may become pregnant.

Adapted from Qureshi WA, Rajan E, Adler DG et al. American Society for Gastrointestinal Endoscopy. ASGE Guideline: Guidelines for endoscopy in pregnant and lactating women. Gastrointest Endosc 2005; 61(3):357–362.

3.1 Anesthetic agents

3.1.1 Propofol

A number of short-acting intravenous general anesthetics are used by anesthetists to provide general anesthesia, one of which is propofol. Propofol (Table 5) is an ideal drug for endoscopy with a rapid onset of action, short half-life, and amnesic properties. Recently, the use of propofol within endoscopy has increased, leading to a debate as to whether only an anesthetist is adequately trained to give propofol or whether gastroenterologist-directed propofol (GD-P) is safe and medicolegally reasonable. There is increasing evidence that propofol can safely be administered by non-anesthesiologists. A recent worldwide multicenter review of 521 000 patients given propofol for endoscopy found that between 0.1 and 0.4 per 1000 patients required assisted ventilation. Four patients required endotracheal intubation, one suffered a neurological injury and there were three deaths, which all occurred in patients with significant co-morbidity, underscoring the importance of seeking anesthetic input for any patient with an ASA >3. Currently, the decision to deliver gastroenterologist-directed propofol is often dictated by institutional guidelines or legal restrictions and it is important to check what the local gastroenterology society or legal guidelines are.

Table 5 Propofol

Side-effects	Hypotension
	Respiratory depression and apnea
	Pain at the injection site
	Myoclonus
Contraindications	Children under the age of 3
	Pregnant women or nursing mothers
	Known hypersensitivity to propofol or any component of its formulation
Use with care	Patients with cardiac, respiratory, hepatic or renal impairment
Use with care	Patients with substantial blood loss or hypotension
Use in pregnant women	FDA Category B
Interactions	Drugs which will potentiate the effect of propofol
	Benzodiazepines
	Narcotics
Reversal agent	None

For gastroenterologists involved in propofol administration it is essential that the following criteria are followed:

• There is an established protocol for drug administration.

• The sedation team must have appropriate education and training in the administration of propofol and be capable of rescuing the patient from general anesthesia.

• There is continuous patient assessment of clinical and physiologic parameters throughout the procedure.

Note

Propofol has a narrow therapeutic window with no reversal agent.

Propofol is a hypnotic with minimal analgesic effect. It produces sedation and amnesia at sub-hypnotic doses. Its mode of action is by potentiating the effects of GABA through a reduction in the rate of GABA-receptor dissociation. It is highly lipid soluble with an onset of action of 30–45 seconds, with a peak effect at 1–2 minutes. Its duration of effect is 4–8 minutes. It is metabolized in the liver by conjugation with glucuronide and sulfate followed by renal excretion. Neither cirrhosis nor renal impairment significantly affects its pharmacokinetic profile but this is potentiated if given with an opioid or benzodiazepine and its pharmacokinetics are affected by weight, sex, and age.

Propofol can either be given alone or in combination with a small dose of opioid or benzodiazepine. The rationale for the addition of a second agent is two-fold. First, propofol does not have any analgesic properties. Second, the addition of a second agent allows lower doses of both drugs to be used and has the potential for partial pharmacologic reversibility with either naloxone or flumazenil.

Note

Propofol must be discarded if not used within 6 hours.

Clinical Tip

Decrease the dose in the elderly by 20%.

Dose

Propofol alone:

• Initial dose 10–40 mg

• Additional doses of 25–75 µg/kg per min or IV bolus dose of 10–20 mg with a minimum of 20–30 seconds between doses.

Combination dose:

• Pre-induction dose of either an opioid (fentanyl, 25–75 µg; meperidine, 25–50 mg), a benzodiazepine (midazolam 0.5–2.5 mg). A combination of both an opioid and benzodiazepine has also been used (Cohen et al. 2007).

• An induction dose of propofol is then given (5–15 mg) followed by additional boluses of 5–15 mg titrated to effect (Cohen et al. 2007).

• The dose should be decreased by 20% in patients over 60 years of age. Slower maintenance rate should be used and rapid bolus administration avoided.

Clinical Tip

The dose of propofol must be individualized based on the patient’s total body weight.

Warning!

BEWARE: Combining propofol with opiod or benzodiazepine increases the risk of respiratory depression and apnea. The dose should be decreased if given in combination with benzodiazepines or narcotics.

3.1.2 Benzodiazepines

Benzodiazepines have sedative, anxiolytic and amnesic properties. The mechanism of action appears to intensify the physiologic inhibitory mechanisms mediated by γ-aminobutyric acid (GABA).

The most commonly used benzodiazepines are diazepam and midazolam. Midazolam is eliminated more rapidly and induces stronger anterograde amnesia than diazepam, allowing for rapid normalization of psychological tests (less than 4 hours). Midazolam is not associated with thrombophlebitis or histamine release, and generates a higher rate of patient satisfaction than diazepam. For these reasons diazepam is used less frequently for intravenous administration compared to midazolam.

3.1.2.1 Midazolam

Midazolam (Table 6) has a peak onset of action of 1–2 minutes, with a peak effect within 3–4 minutes. Its onset of action is more rapid if combined with an opioid (1.5 minutes), and sedation deeper. The pharmacokinetic profile is linear, over 0.05–0.4 mg/kg, allowing predictable dosage titration. Its duration of effect is 15–80 minutes. Midazolam is metabolized in the liver and secreted in the urine. Plasma clearance is reduced in the elderly, the obese, and patients with renal or hepatic impairment. The bioavailability of midazolam is increased by 30% in patients using a histamine H₂-receptor antagonist.

Table 6 Midazolam

Side-effects	Respiratory depression
	Hypotension (especially when combined with an opioid)
	Cardiac dysrhythmias (rare)
	Paradoxical restlessness, agitation, disinhibition^a
Contraindications	Narrow angle glaucoma (midazolam lowers intraocular pressure)^b
	Myasthenia gravis
	Known hypersensitivity to diazepam or any component of its formulation
Use with care	Elderly
Use with care	Chronic obstructive airway disease (COAD)
Use in pregnant women	FDA Category D
Use in pregnant women	Increased risk of congenital malformations suggested in several studies in the 1st trimester
Interactions	Drugs which will potentiate the effect of midazolam:
	Alcohol, analgesics, anti-epileptics, anxiolytics, depressants, neuroleptics, tranquilizers
	Cytochrome P-450 inhibitors – HAART^c, erythromycin, fluconazole, diltiazem
	Drugs which will decrease the effect of midazolam:
	Cytochrome P-450 inducers – phenytoin, rifampicin, carbamazepine
Reversal agent	Flumazenil

^a Consider this side-effect in patients who become increasingly agitated, despite increasing doses of midazolam.

^b May be used in patients with open-angle glaucoma if they are on appropriate therapy.

^c HAART, highly active anti-retroviral therapy.

3.1.2.2 Diazepam

Diazepam (Table 7) has an onset of action of 2–3 minutes with a peak effect after 3–5 minutes, with a duration of 360 minutes. It is metabolized in the liver to active metabolites which undergo renal excretion. This half-life is increased in patients with hepatic or renal impairment.

Table 7 Diazepam

Side-effects	Respiratory depression, dyspnea
Side-effects	Thrombophlebitis
Contraindications	Acute narrow-angle glaucoma
	Open angle glaucoma (unless on appropriate therapy)
	Myasthenia gravis
	Known hypersensitivity to diazepam or any component of its formulation
Use with care	Patients with hepatic, renal or cardiopulmonary impairment
Use in pregnant women	FDA Category D
Use in pregnant women	Increased risk of congenital malformation in the first trimester suggested in several studies
Interactions	Drugs which will potentiate the effect of diazepam:
	Antifungal agents (itraconazole, ketoconazole), cimetidine, disulfiram, fluvoxamine, isoniazid, non-nucleoside reverse transcriptase inhibitors (i.e. delavirdine, efavirenz), protease inhibitors (i.e. indinavir), macrolide antibiotics (i.e. erythromycin), OCP, omeprazole
	Drugs which will decrease the effect of diazepam:
	Rifamycin, theophyllines
	Drugs which diazepam may increase the effects of:
	Digoxin
Reversal agent	Flumazenil

Dose

• Initial dose 5–10 mg IV over 1 minute

• Wait 5 minutes before giving additional doses

• Usually a maximum of 10 mg is given, although 20 mg may be required if an opioid is not being co-administered.

Warning!

BEWARE: Respiratory depression is common in patients who receive a combination of diazepam and an opioid.

3.1.2.3 Reversal agent for benzodiazepines: Flumazenil

Flumazenil (Table 8) antagonizes benzodiazepines by competitively inhibiting GABA receptors. It antagonizes the CNS effects of benzodiazepines reversing respiratory depression, over sedation, psychomotor impairment, and memory loss. It has an onset of action of 1–2 minutes, with a peak effect after 3 minutes, and an average duration of 1 hour. It is metabolized in the liver.

Table 8 Flumazenil

Side-effects	Anxiety, agitation, seizures
Contraindications	Patients who have been given a benzodiazepine for potentially life-threatening condition (e.g. control of intracranial pressure or status epilepticus)
	Patients with signs of serious tricyclic antidepressant overdose
	Known hypersensitivity to flumazenil or any component of its formulation
Use with care	Patients on long-term benzodiazepines, chloral hydrate, carbamazepine or high-dose tricyclic antidepressants, as it may precipitate withdrawal symptoms or convulsions
Use with care	Flumazenil is not recommended in epileptic patients taking benzodiazepines as it may cause convulsions
Use in pregnant women	FDA Category C
Interactions	Flumazenil will block the effects of non-benzodiazepines acting on the BDZ receptors

Dose

• Initial dose of 0.1–0.3 mg over 15 seconds

• Additional doses of 0.2 mg can be given every minute to a maximum dose of 1 mg. Repeated doses can be administered at 20 minutes intervals if re-sedation occurs with no more than 1 mg administered at any one time and no more than 3 mg in any 1 hour.

3.2 Opioid analgesics

Most opioid analgesics have an analgesic and sedative effect without inducing amnesia. Opioid analgesics exhibit good bioavailability when administered parenterally. They act by crossing the blood–brain barrier, and act on the specific receptors of the brain and spinal cord.

Fentanyl has a rapid, short and potent action, making it a good opioid analgesic for gastrointestinal endoscopy, where rapid recovery post-sedation is important. Pethidine (meperidine) is a less potent narcotic analgesic, and its use is declining due to its histamine release and cardiac side-effects.

3.2.1 Fentanyl

Fentanyl (Table 9) is a synthetic opioid. It is highly potent with 100 µg (0.1 mg) equivalent to 10 mg of morphine or 75 mg of pethidine (meperidine). It has a rapid onset of action of 1–2 minutes, with a peak effect within 3–5 minutes and a duration of action of 30–60 minutes. It is metabolized in the liver to active metabolites, which are excreted in the urine.

Table 9 Fentanyl

Side-effects	Respiratory depression (dose dependent)
	Hypotension
	Bradycardia (responsive to atropine)
Contraindications	Myasthenia gravis (can cause severe muscle rigidity)
	MAOIs: other narcotic analgesics have been reported to interact with MAOIs (see pethidine). Although this has not been reported for fentanyl, there are insufficient data to establish that this does not occur and fentanyl should therefore not be given to patients taking MAOIs
	Known hypersensitivity to fentanyl or any component of its formulation
Use with care	Fentanyl can cause severe bronchospasm and should be used with extreme caution in patients with asthma
	Patients with respiratory, hepatic or renal impairment
	Patients with bradycardia
Use in pregnant women	FDA Category C
Interactions	Drugs which will potentiate the effect of fentanyl:
Interactions	CNS depressors (benzodiazepines, neuroleptics, hypnotics)
Reversal agent	Naloxone

MAOIs, monoamine oxidase inhibitors.

Clinical Tip

Decrease dose by 50% in elderly patients.

Dose

• Initial dose 50–100 µg. If being given with a benzodiazepine, it should be given first to allow accurate dose titration.

• Wait 2–5 minutes before giving additional doses.

• Additional doses of 25 µg can be given to a maximum dose of 200 µg.

• The dose should be decreased by 50% in elderly patients.

Clinical Tip

Opioids should be given before benzodiazepines to allow accurate dose titration.

3.2.2 Pethidine (meperidine)

Pethidine (Table 10) is a synthetic opioid with sedative and analgesic properties. It has an onset of action of 3–6 minutes, with a peak effect at 6–7 minutes. Its duration of effect is 60–180 minutes. It is converted into an active metabolite, normeperidine, in the liver and is excreted in the kidneys.

Table 10 Pethidine

Side-effects	Respiratory depression
	Hypotension
	Irritability, tremors, agitation and convulsions
Contraindications	Myasthenia gravis
	MAOIs within the previous 14 days as pethidine may cause sweating, excitation, rigidity, hypertension, hypotension or coma
	Known hypersensitivity to pethidine or any component of its formulation
Use with care	Patients with renal impairment and the elderly
Use in pregnant women	FDA Category B
Use in pregnant women	Does not appear to be teratogenic in two studies and is preferred over morphine or fentanyl which are both Category C
Interactions	Drugs which will potentiate the effect of pethidine:
Interactions	CNS depressors (e.g. benzodiazepines, neuroleptics, hypnotics)
Reversal agent	Naloxone

MAOIs, monoamine oxidase inhibitors. These include dextroamphetamine, Emsam, iproniazid, iproclozide, isocarboxazid, linezolid, moclobemide, nialamide, phenelzine, rasagiline, selegiline, toloxatone, tranylcypromine.

Dose

• Initial dose 25–50 mg

• Wait 2–5 minutes before giving additional doses

• Additional doses of 25 mg can be given to a maximum dose of 150 mg

• A reduced initial dose should be given in the elderly, debilitated patients or those with renal or hepatic impairment.

Warning!

BEWARE: Pethidine should not be used with MAOIs.

3.2.3 Reversal agent for opioids: naloxone

Naloxone (Table 11) has a similar structure to oxymorphone and antagonizes the CNS effects of opioids including respiratory depression, excess sedation and analgesia. It has an onset of action of 1–2 minutes, a peak effect at 5 minutes and a half-life of 30–45 minutes.

Table 11 Naloxone

Side-effects	Pain
	Hypertension, tachycardia
	Pulmonary edema (rare)
Contraindications	Known hypersensitivity to naloxone or any component of its formulation
Use in pregnant women	FDA Category B
Interactions	No significant interactions

Dose

• 0.2–0.4 mg (0.5–1.0 g/kg) IV every 2–3 minutes

• Additional doses may be required after 20–30 minutes.

Clinical Tip

The half-life of fentanyl is longer than naloxone, thus repeated doses of naloxone may be required.

3.3 Other drugs used for sedation

Several other drugs have been used for sedation including promethazine, dexmedetomidine, droperidol, ketamine, and nitrous oxide. Detailed information about these drugs can be found in Riphaus et al (2009).

3.4 Pharyngeal anesthesia

Topical anesthesia suppresses the gag reflex and can be used alone in cooperative patients. It can also be combined with intravenous sedation, and has been shown to be associated with improved patient tolerance and ease of endoscopy. However, it is important to be aware that combining pharyngeal anesthesia with intravenous sedation may increase the risk of aspiration and appropriate precautions must be taken. Other complications have been reported, including methemoglobinemia and anaphylaxis, although these are rare. The most commonly used agent is lidocaine, which is administered as an aerosol spray to the pharynx, the effect of which lasts up to 1 hour. Patients should not drink for half an hour following the procedure and their gag reflex should be checked prior to imbibing food or drink.

4 Management of the complications of sedation

A total of 50% of all endoscopy complications are sedation-related. The commonest of these are prolonged sedation and respiratory depression.

4.1 Prolonged sedation

Flumazenil should be given to counteract benzodiazepines, while naloxone should be given if opioids have been used. If both benzodiazepines and opioids have been used, then flumazenil and naloxone should be given.

Warning!

BEWARE: The half-life of flumazenil is shorter than that of midazolam and other benzodiazepines, thus repeated doses may be required.

4.2 Respiratory depression/hypoxia

The commonest cause of hypoxia is depression of the respiratory center. Other rarer causes of hypoxia include laryngospasm, obstruction of the upper airway by the tongue, aspiration or air insufflation during endoscopy, which can increase intra-abdominal pressure and alter the ventilation-perfusion ratio.

In any patient with hypoxia, the following steps should be taken:

• Encourage or stimulate the patient to breathe deeply

• Provide supplemental oxygen or increased oxygen

• Basic airway management:

Clear airway including suction

Jaw thrust maneuver

Insert Guedel airway if necessary

• Reverse sedation

• Give positive pressure ventilation if spontaneous ventilation is inadequate.

Warning!

BEWARE: Patients with a baseline oxygen saturation of <95% have a greater risk of hypoxia.

4.3 Circulatory insufficiency

Sedatives induce venodilatation, which can provoke circulatory collapse in hypovolemic patients secondary to an abrupt inhibition of venous return. It is essential to establish a normal circulatory volume prior to administration of sedation, particularly in the elderly or dehydrated patients, or patients who have experienced gastrointestinal bleeding.

Intravenous access should be inserted prior to commencing endoscopy in all patients. Two large bore intravenous cannulae should be inserted prior to commencing the endoscopy in patients at risk of circulatory insufficiency (i.e. GI bleeding). In hypotensive patients:

• Elevate patient’s legs

• Give IV fluids

• Reverse sedation

• Use vasopressors if required.

Clinical Tip

Ensure that patients who are hypovolemic are fully resuscitated prior to sedation.

4.4 Quality assurance

It is essential for quality assurance that all adverse events (Box 4) should be recorded and analyzed, and appropriate changes made to sedation protocols.

Box 4

Adverse events

• Hypoxemia requiring intervention.

• Hypotension or bradycardia requiring pharmacological treatment.

• Pulmonary aspiration.

• Laryngospasm.

• Unanticipated use of reversal agents.

• Unanticipated hospitalization.

From Cohen LB, Deluge MH, Isenberg J et al. AGA Institute review of endoscopic sedation. Gastroenterology 2007; 133:675–701..

5 Recovery and discharge

5.1 Recovery monitoring

All patients should be monitored in a recovery room by a trained nurse who has appropriate training and experience, with one staff member for every six patients. The following should be measured regularly:

• Level of consciousness

• Hemodynamic parameters

• Oxygenation

• Pain/discomfort.

Standardized discharge criteria (Box 5) should be used and followed. All patients who are undergoing outpatient sedation must be driven home and have a friend or relative remain with them overnight. On discharge, patients should receive written instructions and contact numbers in case of emergency. This should include instructions on diet, activity, medication, not to consume alcohol or drive for 24 hour as well as follow-up and a telephone number to be called in case of emergency. It should be stressed to patients that no important decisions should be made during the 24 hour period.

Further Reading

2002 American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non-Anesthesiologists. Practice guidelines for sedation and analgesia by Non-anesthesiologists. Anesthesiology. 2002;96(4):1004-1017.

Cohen LB, Deluge MH, Isenberg J, et al. AGA Institute review of endoscopic sedation. Gastroenterology. 2007;133:675-701.

2003 Guidelines for conscious sedation and monitoring during gastrointestinal endoscopy. Gastrointest Endosc. 2003;58:317-322.

2005 Guidelines for endoscopy in pregnant and lactating women. Gastrointest Endosc. 2005;61:357-362.

2002 Guidelines for the use of deep sedation and anesthesia for gastrointestinal endoscopy procedures. Gastrointest Endosc. 2002;56:613-617.

Riphaus T, Wehrmann T, Weber B, et al. S3 Guidelines: sedation for gastrointestinal endoscopy 2008. Endoscopy. 2009;41:787-815.

Vargo JJ, Cohen LB, Rex DK, et al. Position statement: nonanesthesiologist administration of propofol for GI endoscopy. Gastrointest Endosc. 2009;70(6):1053-1059.

Useful Facts websites

A-Z Drug Facts. www.drugs.com/ppa/midazolam-hydrochloride.html.

Safety and sedation during endoscopic procedures. http://www.bsg.org.uk/clinical-guidelines/endoscopy/guidelines-on-safety-and-sedation-during-endoscopic-procedures.html.

Sedation Facts. www.sedationfacts.org.

2.4 Chromoendoscopy and tattooing

Christophe Cellier

Summary

Introduction 72

1. Indigo carmine 72

2. Acetic acid 73

3. Lugol’s iodine 74

4. Methylene blue 75

5. Toluidine blue 75

6. Crystal violet 76

7. Tattooing 76

Key Points

• Indigo carmine and Lugol’s iodine solution should be available in all endoscopy units.

• Indigo carmine is extremely useful for relief enhancement of the mucosa.

• Lugol’s iodine is used for detection of squamous esophageal dysplasia or superficial malignancies; it can be used with toluidine blue.

• Acetic acid is useful for detecting mucosal anomalies in Barrett’s esophagus.

• Methylene blue stains intestinal metaplasia, but its sensitivity for identifying dysplasia is controversial.

• The histological nature of a polyp can be determined by using a magnifying endoscope in conjunction with indigo carmine or crystal violet staining.

• The following concentrations are used: indigo carmine 0.2%, acetic acid 1%, Lugol’s iodine 2%, methylene blue (0.5%), toluidine blue (1%).

Introduction

In many settings, chromoendoscopy enhances diagnostic precision by bringing to light abnormalities that were not visible prior to staining. Chromoendoscopy agents are inexpensive, and with practice, it only takes a few minutes to perform. The high percentage of superficial malignancies detected in Japan is in part attributable to the widespread use of chromoendoscopy there. Contrast agents, all of which are used in an aqueous solution, fall into the following categories:

• Relief-enhancement or surface contrast agents

Indigo carmine

Acetic acid

• Contrast agents that react specifically with stained mucosa (vital stains)

Lugol’s iodine solution

Methylene blue

Toluidine blue

Crystal violet.

The mucosa must always be carefully examined prior to staining, while use of a spray catheter allows for homogeneous coverage of the target area.

1 Indigo carmine

Used in concentrations ranging from 0.1 to 0.4%, indigo carmine is a surface contrast material, i.e. it is not absorbed by the mucosa. This agent brings out relief abnormalities in that it stains the bottom of an ulcer or penetrates fissures, and in so doing delineates a tumor, brings to light polyps that go undetected during standard white light examinations, or shows the central depression on the surface of a polyp that has already undergone malignant transformation (Fig. 1).

Figure 1 Indigo carmine 0.2% in a colonic polyp.

1.1 Indications

Indigo carmine is indicated in following settings:

• To delineate a sessile polyp prior to and following endoscopic resection

• To accentuate surface irregularities or visualize a surface ulceration

• To highlight areas for biopsy in Barrett’s esophagus

• To assist analysis of the pit pattern of a polyp (Fig. 2)

• To detect a superficial malignancy or dysplasia of the stomach or colon

Figure 2 Chromoendoscopic classification of colonic mucosal pit patterns (after Kudo). Six types of pit pattern are recognized: types I, II, IIIL, IIIS, IV, and V. (A) Type I small round pits seen in normal mucosa. (B) Larger, symmetrical type II stellar pits seen in hyperplastic polyps. (C,D) Type IIIS, small tubular pits. (E) Type IIIL, large tubular, non-branching pits. (F) Type IV, gyrus or branched pits. (G) Type V, loss of pit pattern or irregular, non-structured pits. Types IIIL, IIIS, IV, and V correlate closely with neoplasia. Most adenomas have type IIIL pits, while type IIIS is associated with depressed lesions. Type V pattern is strongly associated with the presence of malignancy.

Concurrent use of a magnifying (and preferably high resolution) endoscope allows more detailed and precise images to be obtained. In the following settings, it is necessary to stain the entire colonic or duodenal mucosa:

• HNPCC syndrome, where polyps may only appear if they are stained

• Long standing ulcerative colitis, during surveillance colonoscopy

• Celiac disease (Fig. 3).

Figure 3 Celiac disease seen with white light endoscopy (right) and after application of 0.2% indigo carmine.

1.2 Preparation

To obtain 25 mL of 0.4% indigo carmine solution, transfer 10 mL of 1% indigo carmine to a 30 mL syringe and add 15 mL of water. To obtain 50 mL of a 0.2% indigo carmine solution, add 40 mL of water to a 50 cc syringe after transferring 10 mL of 1% indigo carmine to it.

1.3 Staining procedure

The area can be sprayed either using a spray catheter or by adding 10 mL of solution with 40 mL of air in a 50 mL syringe directly in the working channel. The contrast material may disappear quickly, and it is sometimes necessary to re-spray.

1.4 Precautionary measures

There are no contraindications for the use of indigo carmine.

2 Acetic acid

Acetic acid, which has long been used to diagnose cervical cancer at colposcopy, has recently come into use for assessment of Barrett’s esophagus. The chemical whitens inflammatory and dysplastic areas, provoking edema that allows for more precise assessment of the mucosal surface (Fig. 4).

Figure 4 Acetic acid staining of Barrett’s esophagus. (A) White light endoscopy. (B) NBI following acetic acid spray

(Courtesy of Dr Marcia Canto, Johns Hopkins Hospital).

3 Lugol’s iodine

Lugol’s iodine solution stains normal non-keratinized squamous epithelium of the esophagus, and does not stain the following:

• Malignant tissue

• Dysplasia

• Inflammatory or eroded mucosa

• Gastric metaplasia

The brownish-black staining obtained with Lugol’s iodine is not homogenous because of the variable concentrations of glycogen in the epithelium. Glycogenic acanthosis accentuates the coloration. Non-stained areas exceeding 5 mm in diameter should be biopsied (Fig. 5).

Figure 5 Lugol’s iodine staining. (A) White light image showing Paris type 0–IIa lesion, which is nearly circumferential. High-grade dysplasia was found on histology following endoscopic mucosal resection. (B) The same lesion seen with autofluorescence. (C) The same lesion following application of 2% Lugol’s iodine. Note how much more extensive proximal high-grade dysplasia (non-staining) is visible with Lugol’s iodine.

Clinical Tip

It is the non-staining areas that are abnormal with Lugol’s iodine.

3.1 Indications

When used solely in the squamous epithelium of the esophagus, Lugol’s iodine allows:

• Detection of early malignancy

• Accurate delineation of a malignancy prior to endoscopic treatment

• Determination of synchronous areas of dysplasia or malignancy.

Numerous studies, particularly from Japan, have reported using Lugol’s iodine solution for the detection of early esophageal neoplasia. A study by Dawsey et al (1998) is particularly informative in this regard. In this study, 225 Chinese patients underwent chromoendoscopy using Lugol’s iodine. Prior to staining, all visible lesions were biopsied. After staining, biopsies were taken from areas that exhibited abnormal or no coloration. The sensitivity of endoscopy for the detection of an early malignancy or dysplasia was 62% without staining and 96% with staining, with specificities of 79% and 63%, respectively.

3.2 Preparation

25 mL of a 2% Lugol solution is required.

3.3 Staining procedure

The patient should be intubated prior to the procedure so as to allow for staining up to the upper esophageal sphincter.

• Starting from the cardia, spray the esophagus with 25 mL of the Lugol’s iodine while gradually withdrawing the endoscope.

• Wait 2 minutes. Then biopsy all non-stained areas whose diameter exceeds 5 mm, bearing in mind the following:

Specificity is lower for non-stained areas that are <5 mm in diameter.

Non-stained benign areas tend to be round, whereas malignant areas generally exhibit irregular margins and are >1 cm in diameter.

3.4 Precautionary measures

To minimize the risk of burns, make sure that Lugol’s iodine does not come into contact with the patient’s or user’s face. This can be done by placing a covering over the patient’s left cheek and mouth. Classical allergy to iodine is not a contraindication for use of Lugol’s iodine, which also has little or no effect on thyroid function. Spraying from the upper oesophageal sphincter while moving distally to the cardia may help to avoid regurgitation in the absence of intubation.

4 Methylene blue

Methylene blue, which is absorbed by the mucosa in the colon and small intestine, allows the detection of abnormal intestinal epithelium and for more detailed visualization of the intestinal mucosa (Fig. 6).

Figure 6 Methylene blue staining.

4.1 Indications

To detect dysplasia in Barrett’s esophagus and chronic gastritis. For the stomach, intestinal metaplasia staining displays 96% sensitivity and 95% specificity. For Barrett’s esophagus, Canto et al (2002) demonstrated that specific intestinal metaplasia staining displays 95% sensitivity and 97% specificity. It has also been reported that less intense and somewhat irregular methylene blue impregnation in a stained area suggests the presence of dysplasia (the dysplastic cells do not absorb the contrast material as readily) and can be used to guide biopsies. This latter finding has been contested by other authors.

4.2 Preparation

To obtain 20 mL of a 0.5% methylene blue solution (the volume needed for a 5 cm long Barrett’s segment):

• Draw up ×10 1 mL vials of 1% methylene blue into a 30 mL syringe.

• Add 10 mL of water for an injectable solution.

To obtain 20 mL of a 1% acetylcysteine solution (used to remove mucus prior to methylene blue staining):

• Proceed as above, but using 1 mL 20% acetylcysteine (Mucomyst)

• Add 19 mL of water for an injectable solution.

4.3 Staining procedure

Spray the acetylcysteine solution on the target area (Barrett’s esophagus or gastric atrophy). Wait 1 minute and then spray methylene blue on the area. Wait 2 minutes. Irrigate abundantly using ×3 50 mL syringes while suctioning the fluid regularly to avoid pulmonary aspiration. Biopsy the blue areas, i.e. areas that exhibit irregular coloration (Fig. 7).

Figure 7 Methylene blue stain of Barrett’s esophagus secondary to cleaning using acetylcysteine solution.

4.4 Colon and small intestine relief enhancement

The indications here are the same as those for indigo carmine. However, a mucolytic solution is unnecessary, as this procedure does not entail exact delineation of the mucosa of the abnormal area. Spray the target area (using a spray catheter) with 0.5% methylene blue solution.

4.5 Precautionary measures

There are no contraindications for the use of methylene blue.

5 Toluidine blue

As it is absorbed by nucleic acids, toluidine blue stains malignant or dysplastic lesions with elevated mitotic activity.

5.1 Indications

Toluidine blue stains esophageal malignancies and dysplasia, although Lugol’s iodine solution has supplanted it to a great extent. Nonetheless, it is useful as an adjunct to Lugol’s, particularly in cases where it is essential to clearly delineate the limits of a superficial malignancy before performing endoscopic mucosal resection. In such a case, toluidine blue staining should be performed first, as otherwise the product will stain not only the lesion but also normal epithelium that was altered by Lugol’s iodine solution.

5.2 Preparation

25 mL of each of the following solutions are needed:

• 1% toluidine blue solution

• 1% N-acetylcysteine acid solution for mucus removal.

5.3 Staining procedure (Monnier technique)

Spray the target area with 1% N-acetylcysteine solution. Wait 1 minute. Then spray the area with toluidine blue solution. Wait 2 minutes. Irrigate abundantly using 50 mL syringes while suctioning the fluid regularly to avoid inhalation. Biopsy the bluish areas.

5.4 Precautionary measures

Toluidine blue is contraindicated in the presence of abnormally low G6PD enzyme activity, because of the risk of precipitating hemolysis.

7 Tattooing

Tattooing of the gastrointestinal wall (usually the colon) is useful for marking the location of a lesion or for endoscopic surveillance of an area where, for example, a large or malignant polyp has been removed (Fig. 9). A sterile carbon suspension (e.g. Sterimark; GI Spot), rather than India ink should be used.

Figure 9 Tattooing. (A) Injection needle is inserted into the submucosa and tattoo is injected. (B) Following tattoo.

7.1 Tattooing procedure

Agitate the syringe vigorously for 15–20 seconds, so as to suspend the solution evenly. Insert a sclerotherapy needle into the submucosa at an oblique angle (30–45°). The needle should not be inserted at right angles, as this could result in serosal penetration and extensive black discoloration of the peritoneum. Inject 0.5–0.75 mL of the marker in each of the four quadrants just distal to the lesion in the right colon and just proximal to the lesion in the rectosigmoid. Should surgery be performed, the surgeon can use the site of tattoo for planning the appropriate surgical resection margin. Do not inject more than 5 mL of the marker.

Further Reading

ASGE Technology Committee. Technology Status Evaluation Report. Endoscopic tattooing. Gastrointest Endosc. 2002;55:811-814.

Askin MP, Waye JD, Fiedler L, et al. Tattoo of colonic neoplasm in 113 patients with a new sterile carbon compound. Gastrointest Endosc. 2002;56(3):339-342.

Canto MI, Yoshida T, Gossner L, et al. Chromoscopy of intestinal metaplasia in Barrett’s esophagus. Endoscopy. 2002;34:330-336.

Dawsey SM, Fleisher DE, Wang GQ, et al. Mucosal iodine staining improves endoscopic visualization of squamous dysplasia and squamous cell carcinoma of the esophagus in Linxian, China. Cancer. 1998;83(2):220-231.

Fennerty MB, Sampliner RE, McGee DL, et al. Intestinal metaplasia of the stomach: identification by a selective mucosal staining technique. Gastrointest Endosc. 1992;38(6):696-698.

Kiesslich R, Von Bergh M, Hahn M, et al. Chromoendoscopy with indigo carmine improves the detection of adenomatous and nonadenomatous lesions in the colon. Endoscopy. 2001;33(12):1001-1006.

Nakamura A, Honma T, Suzyki Y, et al. The usefulness of crystal violet solution for the magnifying observation of colorectal neoplasm. Gastrointest Endosc. 1999;49(4 Part 2):AB64.

2.5 Pre-endoscopy checklist

Geneviève Obel

Summary

Introduction 77

1. Examination room and equipment check 77

2. Equipment that should be present 77

3. Troubleshooting 78

Key Points

• It is essential to check that all equipment that may be required for a procedure is available and working prior to commencing with the procedure.

• All equipment should be available in duplicate.

Introduction

The equipment should be checked to ensure that it is in working order prior to commencing with any procedure. All endoscopes must be disinfected prior to use (see Ch. 1.10 for a detailed description of disinfection guidelines).

1 Examination room and equipment check

Each examination room should keep a log in which the following is recorded: the time at which the room is first opened each day; the activities that are carried out in the room (listed chronologically); the names of the patients who undergo procedures in the room; the drugs and personnel that are present during each procedure.

• Ensure that the active cord (this is the cord which is attached from the electrosurgical generator to the cautery instrument) is present. Active cords come in different sizes. Make sure that it fits the cautery instruments that you are likely to use.

1.6 Endoscope

• Check white balance

• Check that the endoscope is suctioning and blowing air appropriately by placing the tip in water. Air bubbles should be seen clearly flowing from the tip, while water can be seen on suctioning, running through the suction tubing. Then test that the water function is working properly to clean the lens

• Check that the angulation (right/left, up/down) is working

• For ERCP and linear EUS endoscopes check that the elevator is working.

• Foot pump for water (check that you also have the water pump, appropriate tubing to connect the water pump to the endoscope and a 1 L bottle of normal saline).

2.3 General equipment

• Syringes and sterile water

• Spray catheters

• Stains

• Contrast agent (if fluoroscopy is to be used)

• Simethicone or other anti-foaming agent.

2.4 Polypectomy

• Biopsy forceps

• Foreign-body forceps

• Snares in various forms and diameters

• Straight and side firing APC probes

• Polyp trap filters

• Tripod

• Roth net or equivalent.

2.5 Dilation and stenting equipment

• Selection of esophageal, pyloric and colonic balloons

• Savary wire and dilators

• In complex strictures fluoroscopy, contrast agent, catheter and guidewires may be required

• Selection of esophageal, enteric, and colonic stents (covered, uncovered, and plastic)

• Sclerotherapy needle with contrast or external markers (i.e. paper clip) to mark the upper and lower extent to be stented.

3 Troubleshooting

3.1 The air is not working

• Water bottle is:

Not properly connected to the endoscope

Not properly closed

Empty

Overfilled (check that it is not over the black line)

Cracked or leaking

The O ring valve is worn or defective.

Check that there is water in the bottle. Take it off and make sure that it is tightly closed. Check that it is correctly attached to the box. In Pentax machines there is an up/down valve. Check that this is correctly orientated. If necessary, replace the water bottle with a new one.

• The air/water valve:

is defective

not watertight.

Take the valve off, dip it in some water and see if this helps. Lubricate the O ring with silicone gel. If this does not work, get a new valve.

• Instrument channel valve is leaking: This can occur if the valve has been used multiple times. Replace it with a new valve

• Air function deactivated at the source: Check that the air is on and is on the correct setting (position 2–3)

• Endoscope channel blocked: Clear out the channel by flushing it with 60 mL sterile water or by pushing a biopsy forceps or equivalent through it.

3.2 The suction is not working

Disconnect the suction where it joins the endoscope. Place your finger over the suction tubing. If there is suction, then the problem is within the endoscope. If there is no suction, then the problem is the suction tubing or the wall filter.

The following can be the cause:

• The wall filter is not on

• The wall filter is full

• The liner is defective (replace)

• Ensure that the top of the wall filter and any caps are tightly sealed

• The suction tubing is disconnected. Reinsert the tubing. Sometimes the tubing may not have a good seal. In these cases cut the end off the tubing to improve the seal

• Suction channel is blocked by debris, mucus, coagulated blood, etc. Clean out the suction channel using a 50 cc syringe filled with sterile water. If this fails, you can remove the suction button and attach the suction tubing directly to the suction channel.

3.3 The visibility is poor

• Debris or secretions on lens:

Remove the debris by gently rubbing the tip of the endoscope off the mucosa

Flush the lens by forcefully injecting 50 mL saline through the instrument channel. If this fails and visibility is still poor, the endoscope should be removed, and the lens cleaned with a sterile alcohol swab.

• Lens fogged:

Clean the lens with anti-fog solution.

3.4 Image is too dark

• Too little light: Verify that the light source is in the automatic rather than the manual position

• Lamp burned out: Suspect this if the image is dim or there is no light. The lamp will need to be replaced

• Monitor controls set incorrectly: Check the monitor setting and adjust the light, contrast and colors using the control-panel buttons.

3.5 The image is too bright

• Check that the light level is on automatic and not manual

• Defective electrical contacts: The image is usually distorted. Clean the endoscope’s electrical contacts before plugging it in. Clean the connector contacts using a cotton swab soaked in alcohol.

3.6 The image has a pink tinge

• White balance not set: Repeat white balance

• Faulty BNC cable connection: Verify that each cable is plugged and screwed in all the way on the rear panel of the screen.

2.6 Endoscopy reports

Jean-Christophe Létard

Summary

Introduction 80

1. Administrative section 80

2. Clinical section 80

3. Endoscopy reports 82

Key Points

• An endoscopy report should be legible and clearly written.

• It should incorporate an administrative and clinical section.

• A minimum number of images should be included in the report to document key sections of the procedure and any abnormality detected.

• Well-structured endoscopy reporting databases are an important source of data for audit, quality assurance, training, research, and service improvement.

Introduction

Endoscopy reports should be legible, clearly written, and for archiving reasons, should not be more than one page long. An endoscopy report is composed of an administrative and clinical section. The former relates to the patient, the attending physician and endoscopy assistant who performed the procedure, and the endoscopy unit; the latter relates to the indication for the procedure, the technique used, anesthesia, medical devices, procedure time, and a precise description of the relevant diagnoses and any therapeutic procedures.

1 Administrative section

This section should provide the following information:

• Contact details for the unit where the endoscopy procedure was performed

• Patient’s name, date of birth, gender, address and telephone number

• Patient’s insurance number and insurer (if relevant) or unique hospital identifier

• Type of examination (e.g. gastroscopy, colonoscopy, etc.)

• Date and time of the procedure

• Name, address, telephone number and credentials of any doctor to whom the report is to be sent

• Name and credentials of the endoscopist

• Name and credentials of the endoscopy assistants who disinfected the endoscope(s) used

• Name of the endoscopy assistant(s) involved

• Name and credentials of the anesthesiologist

• Name of any other staff member, e.g. any other doctor, anesthesia nurse, or technician who participated in the procedure

• The initials of the secretary who typed up the report (if appropriate).

It is useful to indicate in the report that the patient was given information describing the risks, benefits, and alternatives to the procedure.

It is important to indicate the patient’s risk of harboring vCJD, as follows:

• Patients without any specific risk factors

• Patients with individual risk factors for prion diseases (treatment with human growth hormone; familial prion diseases; neurosurgery prior to 1995)

• Patients with Creutzfeldt–Jakob disease.

2 Clinical section

This section should provide the following information:

• Indication for the procedure, in accordance with local guidelines; or the reasons and indications for the procedure if they do not fall within the scope of the guidelines

• The manner in which the patient was prepared for the procedure, including the quality of the preparation if undergoing colonoscopy

• The nature of the examination (diagnostic or therapeutic endoscopy)

• The instruments used and their serial numbers; the endoscope/endoscope accessory cleaning and disinfection procedures

• The following anesthesia data: ASA score, drugs used (benzodiazepine, morphine, propofol); intubation in cases of therapeutic endoscopy for the upper GI tract

• The following examination-specific parameters: examination time, any problems encountered during the examination, the anatomic extent of the examination as defined by the most distal point to which the endoscope was inserted. The quality of the pre-procedure preparation and any limitation in the examination must be documented

• A comprehensive descriptive analysis of any lesions observed. Each report should:

Use the minimal standard terminology (MST) for gastrointestinal endoscopy, which is recommended by the European Society of Digestive Endoscopy (ESDE) and the World Organization of Digestive Endoscopy (OMED) (www.omed.org/index.php/resources/re_mst/)

The dimensions of a lesion should be indicated in mm or cm

• A description of any additional diagnostic procedures (biopsies and staining) or therapeutic procedures (e.g. polypectomy, sphincterotomy, etc.) that were performed, including the number of procedures, their exact locations, and the number of the specimen jar into which the specimens were placed

• The conclusion should provide a summary of the examination, including the endoscopic diagnosis indicated by the examination findings. However, no new lesions should be described in this section. The interpretation of the findings should not include any unrelated data, unless a valid explanation for these data is provided

• Codes should be used in the report, based on the International Classification of Diseases

• The images from the examination. This documents the extent of the areas examined, illustrates the pathology that was identified, and provides an impression of the image quality obtained (see Figs 1, 2)

• Comments may be added, particularly if difficulties were encountered during the examination, for example, if abdominal compression or position changes were required or any failure or complication associated with the examination. Diagrams should have captions to indicate lesion characteristics, the examination images (eight images are recommended by the European Society of Gastrointestinal Endoscopy (ESGE); the European Society of Gastroenterology and Endoscopy Nurses and Associates (ESGENA).

Endoscopy reports can either be printed, or may be available as digital endoscopy reports, depending on the system used in the endoscopy unit.

Report findings should be communicated orally to patients on completion of the examination. The patient should be given a definitive printed version of the report before leaving the endoscopy unit, or at a later time. The definitive version that is provided immediately should contain sufficient information to allow the patient to undergo any further therapy within the timescales indicated in the report. The definitive endoscopy report can also be sent to the referring physician.

3 Endoscopy reports

3.1 Upper endoscopy

Figure 1 is an example of the number and quality of images which should be provided.

Figure 1 Upper endoscopy report. This is an example of the number, quality and type of images that should be presented in an endoscopy report (European Society of Digestive Endoscopy, ESDE). (1) View into the upper esophagus from above, 20 cm from the dental arches; (2) lower esophagus, 2 cm above the Z line; (3) upper part of the body, following stomach insufflation; (4) retroverted endoscopic view of the cardia, and fundus; (5) angle of the lesser curvature (reverse view); (6) gastric antrum with the pylorus in the center; (7) centered view of the duodenal bulb (D1); (8) view into the second portion of the duodenum, from above.

3.2 Colonoscopy

Figure 2 is an example of the number and quality of images which should be provided. The photographs on this page were taken while the endoscope was being withdrawn.