Chapter 10 Preoperative Evaluation and Medication
1. What is the purpose of the preanesthetic visit before the day of surgery?
2. How does the anesthesiologist classify a patient’s physical status?
Comorbidities impacting administration of anesthesia
6. What are the guidelines for cardiovascular evaluation for patients having noncardiac surgery?
7. How long does the patient need to wait after revascularization to undergo elective noncardiac surgery?
8. Should aspirin be continued perioperatively?
9. What can happen if aspirin is stopped abruptly?
10. What percentage of patients with compensated versus decompensated heart failure will have perioperative cardiac complications?
11. What are the main types of heart failure?
12. What are the common causes of systolic and diastolic dysfunction?
13. What finding on an ECG would suggest diastolic dysfunction?
14. For patients with heart failure, which symptoms should prompt echocardiographic evaluation preoperatively?
15. What further evaluation does a patient with heart failure symptoms at rest (decompensated failure or Class IV) need beyond an echocardiogram?
16. Is there a benefit of routine perioperative evaluation of left ventricular (LV) function before surgery?
17. What are the recommendations for preoperative noninvasive evaluation of LV function?
18. Are all cardiac murmurs associated with valvular pathology?
19. Which cardiac murmurs are always pathologic?
20. What are the clinical clues that suggest a patient may have valvular disease?
21. Which planned anesthetics should prompt the anesthesiologist to want an echocardiogram before proceeding with an anesthetic in a patient with a cardiac murmur?
22. When is an echocardiogram indicated in an asymptomatic patient with a cardiac murmur?
23. Are regurgitant or stenotic valvular lesions better tolerated perioperatively?
24. Does aortic stenosis and aortic sclerosis have similar hemodynamic manifestations?
25. Should patients with valvular abnormalities receive antibiotic prophylaxis to prevent infective endocarditis?
26. Which other conditions need antibiotic prophylaxis against infective endocarditis?
27. Should patients undergoing genitourinary (GU) and gastrointestinal (GI) tract procedures take antibiotic prophylaxis to prevent infective endocarditis?
28. For patients meeting criteria for prophylaxis against infective endocarditis, for which procedures is prophylaxis recommended?
29. What conditions are typically associated with a pacemaker and implantable cardioverter-defibrillator (ICD) placement?
30. How should the ICD be managed in the surgical patient?
31. Will a magnet disable an ICD?
32. Which comorbidities are hypertensive patients at risk of?
33. When should surgery be delayed due to elevated blood pressure (BP)? What is severe hypertension?
34. What is the preoperative BP goal for hypertensive patients?
35. Is there a risk in normalizing BP in hypertensive patients?
36. What are predictors of postoperative pulmonary complications?
37. Is chronic obstructive pulmonary disease (COPD) the greatest risk factor for postoperative pulmonary complications?
38. Does well-controlled asthma increase perioperative complications?
39. How can the risk of bronchospasm after tracheal intubation be decreased in patients with obstructive airway disease?
40. If steroids are given, how much steroid should be administered preoperatively to a patient with persistent airway obstruction?
41. Which types of anesthesia are associated with a greater risk of postoperative pulmonary complications (PPC)?
42. Does preoperative testing predict the risk of PPC?
43. Which maneuvers can reduce PPC rates?
44. What is obstructive sleep apnea (OSA)?
45. Which symptoms and risk factors are associated with OSA?
46. What components of the patient’s history or physical examination can identify those at risk of OSA?
47. Which comorbidities are associated with OSA?
48. What impact does OSA have for anesthesia?
49. Should patients having anesthesia bring their continuous positive airway pressure (CPAP) devices to the hospital?
50. What are the American Society of Anesthesiologists’ (ASA) published recommendations for perioperative care of patients with OSA?
51. What are the most common causes of dyspnea?
52. How should dyspnea be evaluated?
53. Is renal insufficiency a risk factor for perioperative complications?
54. When should a patient with renal insufficiency receive dialysis before surgery?
55. Must chronic hyperkalemia be corrected in a patient with renal insufficiency?
56. Does radiocontrast medium worsen renal function in normal patients?
57. Can the risk of renal injury be reduced in patients receiving radiocontrast medium?
58. What are the goals of perioperative glucose control in diabetic patients?
59. If a diabetic patient has an Hb A1c of 12 on the day of surgery with a glucose level of 350 g/dL, should the surgery be cancelled?
60. What body mass index (BMI) defines extreme obesity?
61. Which comorbidities are associated with obesity?
62. Does anemia predict perioperative morbidity and mortality?
63. Does a patient with anemia require further evaluation to identify its cause?
64. What perioperative concerns surround a pregnant patient who needs a nonobstetric
65. Are elderly patients at a higher risk for hospital admission after ambulatory surgery?
66. How does a patient’s do not resuscitate (DNR) status transfer from the hospital ward to the operating room?
Testing
69. Is preoperative testing indicated for every patient?
70. When should preoperative tests be ordered?
71. Should all patients of a certain age receive a preoperative electrocardiogram (ECG)?
72. Do preoperative ECGs or chest radiographs predict postoperative complications?
73. What are the recommendations for obtaining a preoperative ECG?
74. Do all females of childbearing years require a β-human chorionic gonadotropin (β-hCG) assay prior to surgery?
75. Which types of preoperative tests are useful when evaluating patients with severe
comorbidities and undergoing intermediate-high risk procedures?
76. What are the minimal recommendations for testing before anesthesia?
Medications
77. Should all medications be continued perioperatively?
78. Should β-adrenergic blockers (BB) be continued preoperatively?
79. Are there medications that can lower cardiac risk for high-risk patients scheduled for elective noncardiac surgery?
80. What are the benefits of statins perioperatively?
81. Can statins be abruptly stopped?
82. Can neuraxial or peripheral anesthesia be performed on a patient taking aspirin or
83. Should psychiatric medications be continued preoperatively?
84. Should angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) be continued preoperatively?
85. When should low-molecular-weight heparin (LMWH) be discontinued before surgery?
86. How many days before surgery should warfarin be stopped?
87. What should be done if the international normalized ratio (INR) is elevated near the day of surgery?
88. When should patients on warfarin be bridged with LMWH before surgery?
89. In which patients is LMWH contraindicated?
90. How should type 1 and type 2 diabetics be managed preoperatively?
91. Should ultra–long-acting insulin such as glargine be continued on the day of surgery?
92. Does metformin need to be discontinued before the day of surgery?
93. Should oral hypoglycemic drugs be withheld on the day of surgery?
94. Which medications should be continued on the day of surgery?
95. Which medications should be discontinued for surgery?
96. Which herbal medication should not be discontinued abruptly before surgery?
97. Is neuraxial anesthesia contraindicated in patients taking herbal medications?
98. Should monoamine oxidase inhibitors (MAOIs) be discontinued before surgery?
99. Should narcotics, anxiolytics, or nicotine replacement be discontinued before surgery?
100. Should patients taking oral steroids take the steroid on the day of surgery?
101. How much cortisol does a patient typically produce a day?
102. Which patients are at risk for adrenal insufficiency?
103. What risks are associated with high-dose steroids?
104. How should perioperative glucocorticoids be dosed for a patient on chronic steroids?
105. How should anxious patients be premedicated before surgery?
106. What medications can be offered preoperatively to patients with a history of severe postoperative nausea and vomiting (PONV)?
107. Who is at risk for pulmonary aspiration, and how should they be premedicated?
Answers*
1. The purpose of the visit is to interview the patient or guardian and establish a medical, medication, and anesthesia history, and to determine the patient’s functional capacity. At this visit, the anesthesiologist performs a physical examination focusing on the airway, vital signs, and cardiovascular, pulmonary, and neurologic systems; reviews previous diagnostic tests, consultations, and laboratory results; assigns an ASA-physical status (see question 2); and determines whether further tests are necessary before surgery. An anesthetic plan is formulated and discussed with the responsible adult before informed consent is obtained. Medical therapies are optimized, fasting instructions are provided, and preoperative medication recommendations are given. (165-166, Figure 13-1)
2. The American Society of Anesthesiologists (ASA) Physical Status Classification ranges from ASA 1 to ASA 6. A patient who is classified as ASA 1 is healthy, without disease. ASA 2 is for patients with mild systemic disease that is well controlled. ASA 3 refers to patients with systemic disease sufficiently severe to limit daily activity (renal failure on dialysis or class 2 heart failure). ASA 4 is for patients with a severe disease that is a constant threat to life and seriously limits daily activities (acute myocardial infarction or respiratory failure requiring mechanical ventilation). ASA 5 refers to moribund patients likely to die in less than 24 hours with or without surgery. ASA 6 is reserved for brain-dead patients who are organ donors. The letter E is added to a classification if the surgical procedure is an emergency. (Table 13-1)
History and physical examination
3. A patient’s functional capacity is measured in metabolic equivalents (MET). One MET is equivalent to the consumption of 3.5 mL O2/kg/min. A patient able to eat, get dressed, and work at a computer has a MET of 1. A patient who can walk two blocks has a MET of 3. Climbing one flight of stairs equals a MET of 5; a MET of 10 is running or jogging briskly. A MET of 12 is achieved with running rapidly for long distances. A patient’s functional capacity predicts outcome, perioperative complications, and indicates the need for further evaluation. (166, Table 13-2)
4. The airway examination is performed to assist in predicting the ease of hand mask ventilation and endotracheal intubation of the patient. If difficult airway management is predicted, then necessary equipment can be set up and skilled personnel alerted and available on the day of surgery. (Figure 13-2, Table 13-3)
5. During the airway examination the following are assessed: the condition of the teeth, the ability of the patient to advance or protrude the mandibular incisors; the tongue size; visibility of the uvula, tonsils, soft palate, or hard palate only (Mallampati classification I-IV); the presence of facial hair; the thyromental distance; and the length, thickness, and range of motion of the neck. (Figure 13-2, Table 13-3)
Comorbidities impacting administration of anesthesia
6. The American College of Cardiology/American Heart Association (ACC/AHA) guidelines have decreased the number of recommendations for testing and revascularization. The approach to this algorithm should stop at the first step that applies to the patient.
If the surgery is not an emergency, then the algorithm is as follows:
Step 5 (poor functional capacity): if the patient has poor functional capacity and needs intermediate-risk or vascular surgery, then important clinical predictors (not increased age or elevated blood pressure) are used to determine if more testing is necessary. The five important clinical predictors based on the revised cardiac risk index (RCRI) include ischemic heart disease, compensated or prior heart failure, cerebrovascular disease (stroke, transient ischemic attack), diabetes mellitus, and renal insufficiency. If no clinical predictors are present, the patient may proceed to surgery without further testing. If one or more clinical predictors are present, the patient may proceed to surgery with heart rate control, or noninvasive testing may be considered before surgery if it will change management. (166, Figure 13-3)
7. How long the patient needs to wait after revascularization to undergo elective noncardiac surgery depends on the type of revascularization and the associated period of dual antiplatelet therapy to prevent thrombosis or restenosis. For percutaneous coronary intervention (PCI) without stenting, 2 weeks of dual antiplatelet therapy is required. If a drug-eluting stent (DES) is placed, 12 months of aspirin and thienopyridine therapy (clopidogrel or ticlopidine) are required; a bare metal stent (BMS) requires 1 month of dual therapy. Elective surgical procedures should be delayed past this high-risk period. If a patient with a DES requires a procedure that mandates the discontinuation of thienopyridine therapy, aspirin should be continued perioperatively and the thienopyridine restarted as soon as possible. During the preanesthetic visit, the type of stent (DES or BMS) should be identified and managed perioperatively with a cardiologist familiar with these stents, especially to prevent premature withdrawal of antiplatelet drugs. The patient should be made aware of the risks associated with premature discontinuation of the drugs, including stent thrombosis, myocardial infarction, and death. If stent thrombosis does occur, it is best treated in the immediate postoperative period by percutaneous coronary intervention. (169-170, 180, Table 13-4, Figure 13-4)
8. Patients taking aspirin for primary prevention (no known vascular disease but only to prevent ischemic heart disease or stroke) should stop aspirin 7 days before the procedure. If aspirin is for secondary prevention (for known vascular disease of any type, such as after myocardial infarction, acute coronary syndrome, stent, stroke, or peripheral arterial disease) aspirin should be continued perioperatively unless the procedure is associated with bleeding into a closed space (e.g., intracranial neurosurgery), in which case aspirin is stopped 7 days before the procedure.
If the patient is taking aspirin and clopidogrel, and the condition is low risk (stroke, uncomplicated myocardial infarction, PCI without stenting, or past the high-risk period with stents (see question 8), it is acceptable for the patient to stop clopidogrel 7 days before the surgery and continue aspirin perioperatively. If the patient is taking aspirin and clopidogrel, and the situation is high risk (<2 weeks after PCI without stents, <4 weeks after BMS, <12 months after DES, high-risk stents) then dual antiplatelet therapy is continued unless there is risk of bleeding into a closed space (intracranial), in which case the risk/benefits of antiplatelets are evaluated. If aspirin is stopped, it is best reinstituted early in the postoperative period. (169, 179-180, Table 13-4, Figure 13-4)
9. There is an increased risk of vascular events (including acute coronary syndromes and acute cerebral events) if aspirin is stopped perioperatively. This increase in adverse events may be from a rebound hypercoagulable state when aspirin is withdrawn. (179)
10. The risk of perioperative cardiac complications is 5% to 7% with compensated heart failure and 20% to 30% or higher with decompensated heart failure. (170)
11. Systolic dysfunction (decreased ejection fraction from decreased contractility) and diastolic dysfunction (increased filling pressures with abnormal relaxation but preserved contractility and ejection fraction), or a combination of systolic and diastolic dysfunction. (170-171)
12. Systolic dysfunction is most commonly caused by ischemic heart disease; diastolic dysfunction is associated with hypertension. (171)
13. Left ventricular hypertrophy on an ECG may suggest diastolic dysfunction. (171)
14. Symptoms of recent weight gain, complaints of shortness of breath, fatigue, orthopnea, paroxysmal dyspnea, nocturnal cough, peripheral edema, recent hospitalizations, or necessary changes in medical management prompt echocardiographic evaluation. (171)
15. A patient with heart failure symptoms at rest needs evaluation by a cardiologist before undergoing anesthesia. (171)
16. Routine perioperative evaluation of LV function in patients is not recommended. (Table 13-5)
17. Class IIA (reasonable to perform) recommendations exist for evaluation of LV function in the following patients: patients with dyspnea of unknown origin, with current or previous heart failure with worsening dyspnea, or with another change in clinical status if the LV function has not been evaluated in the previous 12 months. Class IIB (may be considered) recommendations suggest reassessment of LV function in clinically stable patients with previously documented cardiomyopathy, although the recommendations are not well established. (Table 13-5)
18. Not all cardiac murmurs are pathologic. Functional murmurs arise from turbulent flow across the aortic or pulmonary outflow tracts in high output states, such as hyperthyroidism, pregnancy, or anemia. Functional murmurs are not associated with valvular abnormalities. (171, Table 13-6)
19. Diastolic murmurs are always pathologic and require evaluation. (171)
20. Important factors for valvular disease include advanced age, coronary artery disease (CAD), a history of rheumatic fever, volume overload, pulmonary disease, cardiomegaly, an abnormal ECG, or a murmur. (171, Table 13-6)
21. Before general anesthesia, or spinal anesthesia (contraindicated if severe aortic stenosis is present), an anesthesiologist would evaluate a cardiac murmur by echocardiogram. (171)
22. Per ACC/AHA guidelines, there is evidence that echocardiography is useful in murmurs associated with ejection clicks, murmurs that radiate to the neck or back, or grade 3 or louder systolic murmurs. Obtaining an echocardiogram for a patient with a murmur and an abnormal ECG or chest radiograph is a class IIa recommendation; obtaining an echocardiogram for a patient with a grade 2 or softer midsystolic murmur, which is considered innocent or functional by an experienced observer, is a class III recommendation (i.e., not recommended). (171, Table 13-6)
23. Regurgitant valvular lesions are better tolerated perioperatively than stenotic disease. (171)
24. Systolic ejection murmurs are heard in both aortic stenosis and aortic sclerosis. Aortic sclerosis (a calcified valve without narrowing) is associated with a loud murmur, and is more prevalent than aortic stenosis; however, it is aortic stenosis that is associated with a significant compromise in hemodynamics. Patients with severe or critical aortic stenosis should always undergo cardiac evaluation unless the procedure is an emergency. Aortic stenosis is associated with a high risk for perioperative complications. Both conditions are independent predictors of CAD. (171)
25. No, antibiotic prophylaxis is no longer recommended for patients with abnormalities on native valves (e.g., aortic stenosis, tricuspid regurgitation, mitral stenosis from rheumatic heart disease). However, patients with previous episodes of infective endocarditis or a transplanted heart with valvular abnormalities do require infective endocarditis prophylaxis. (171, Table 13-7, Table 13-8)
26. Antibiotic prophylaxis is needed for patients with a prosthetic cardiac valve, previous infective endocarditis, unrepaired congenital heart disease, repaired congenital defects within 6 months of the repair, or lifelong if a residual defect remains. (171, Table 13-8)
27. No, GU and GI tract procedures, unless infection is present, do not require antibiotic prophylaxis against infective endocarditis. (Table 13-7)
28. Antibiotic prophylaxis against infective endocarditis is recommended for all dental procedures that involve manipulation of gingival tissues or the periapical region of the teeth or perforation of oral mucosa, and for procedures on the respiratory tract, or through infected tissue. (Table 13-7)
29. Patients with heart failure, ischemic or valvular disease, cardiomyopathies, or potentially lethal arrhythmias often have a pacemaker or ICD placed. (171-172)
30. First, the patient should carry a wallet card with pertinent information regarding the device. Interference with the device may be caused by monitors, ventilators, chest prepping, cautery, and central line placement. If interference causes unnecessary cardioversion, or an unexpected discharge, patient movement that occurs during a delicate intracranial, spinal, or ocular procedure may be catastrophic. Because of concern for interference causing unexpected discharge and patient movement, ICDs are typically deactivated during procedures. Patients must be connected to monitors, and equipment for cardioversion must be available when ICDs are programmed off. (171-172)
31. A magnet will suspend antishock therapies only. Magnets disable only the antitachycardia function, not the pacing function of an ICD. If the ICD is disabled by a magnet, a defibrillator must be available as an alternate form of antishock therapy. Once the magnet is removed, the antitachycardia function may not resume in some ICD models. Additionally, some ICDs will not respond to a magnet. If an ICD is reprogrammed or if a magnet is used at any time, the device must be reinterrogated and reenabled before the patient leaves a monitored setting. (172)
32. Hypertensive patients may develop end-organ damage depending on the severity and duration of hypertension. Ischemic heart disease, heart failure, renal insufficiency, and cerebrovascular disease are common in hypertensive patients. (172)
33. Severe hypertension is systolic BP greater than 200 mm Hg or diastolic BP greater than 115 mm Hg. Surgery should be delayed for patients with severe hypertension until the BP is less than 180/110 mm Hg. (172)
34. The preoperative goal is to restore BP to normal levels before surgery if significant end-organ damage is present or intraoperative hypotensive techniques are planned. (172)
35. If BP is lowered rapidly and aggressively, a risk of cerebral or coronary ischemia exists. Extreme lowering of BP resulting in intraoperative hypotension is more dangerous than hypertension. (172)
36. Predictors of postoperative pulmonary complications include advanced age, heart failure, COPD, smoking, poor general health (impaired sensorium, functional dependency), and obstructive sleep apnea. (172-174, Table 13-9)
37. No, COPD is not the greatest risk factor for postoperative pulmonary complications. Heart failure, advanced age, and poor general health are associated with a greater risk of postoperative pulmonary complications than is COPD. However, the more severe the COPD, the greater the risk. (173, Table 13-9)
38. No, well-controlled asthma does not increase perioperative complications; however, patients with poorly controlled asthma as evidenced by wheezing are at a higher risk of complications. (172-173)
39. Administration of corticosteroids and β-adrenergic agonists preoperatively decreases the incidence of bronchospasm upon tracheal intubation. (173-174)
40. Prednisone 0.5 to 1 mg/kg orally for 1 to 4 days before surgery for patients likely to have endotracheal intubation is recommended for patients with persistent airway obstruction despite the use of inhaled medication. (174)
41. General anesthesia is associated with a greater risk of PPC. Neuraxial anesthesia and peripheral nerve blocks are associated with a lower risk of PPC. In addition, percutaneous interventions (endovascular repairs) have a lower risk of PPC than open interventions. (174, Table 13-9)
42. Routine pulmonary function tests, chest radiography, or arterial blood gases do not predict PPC risk. (174)
43. PPC rates can be decreased by maximizing airflow in obstructive disease, treating infections and heart failure, and using lung expansion maneuvers such as coughing, deep breathing, incentive spirometry, positive end-expiratory pressure (PEEP), and continuous positive airway pressure (CPAP). (174)
44. OSA is intermittent airway obstruction during sleep. (174, Figure 13-5)
45. OSA is associated with snoring, daytime sleepiness, hypertension, obesity, and a family history of OSA. (174, Figure 13-5)
46. The STOP-Bang questionnaire can be used to identify patients at risk for OSA. The questions address snoring, daytime fatigue, treatment for high blood pressure, observed apneas during sleep, BMI of 35 or more, age of 50 or over, neck circumference greater than 15.7 inches (40 cm), and male gender. Patients are at high risk for OSA if they answer yes to three or more items. (174, Figure 13-5)
47. Patients with OSA have increased rates of diabetes, hypertension, atrial fibrillation, bradyarrhythmias, ventricular ectopy, stroke, heart failure, pulmonary hypertension, dilated cardiomyopathy, and CAD. (174, Figure 13-5)
48. Ventilation by mask, direct laryngoscopy, endotracheal intubation, and fiber-optic visualization of the airway are more difficult in patients with OSA. Patients with OSA may have perioperative airway obstruction, hypoxemia, atelectasis, ischemia, pneumonia, and prolonged hospitalizations. (174-175, Figure 13-5)
49. Yes, if CPAP is used at home, the patient should bring the home CPAP device on the day of the procedure for perioperative use. (174)
50. The ASA recommends that patients with OSA have preoperative diagnosis and treatment. The appropriateness of ambulatory surgery should be reviewed since patients with OSA are at a higher risk for perioperative complications and prolonged hospitalization than are patients without OSA. (175, Figure 13-5)
51. The most common pathologic causes of dyspnea are COPD, asthma, and heart failure. Deconditioning is also a common nonpathologic cause of dyspnea. (175, Figure 13-6)
52. In a patient with dyspnea, history and physical examination determine whether the cause is cardiac, pulmonary, both, or other. Dyspnea of cardiac origin may be caused by myocardial ischemia, angina, heart failure, valvular disease, or pericardial disease, such as tamponade or constrictive pericarditis. Evaluation includes an ECG, chest radiograph, stress test, echocardiogram, and a brain natriuretic peptide level. If the etiology of dyspnea is suspected to be pulmonary, this may be caused by COPD, asthma, pneumonia, lung injury, pulmonary embolism, pulmonary hypertension, restrictive lung disease, pulmonary fibrosis, or pleural disease. Evaluation includes a chest radiograph, arterial blood gases, pulmonary function testing, and chest computed tomography. Other causes for dyspnea include anemia, deconditioning, renal failure, neuromuscular disease, hypothyroidism, and psychogenic. For these causes, a complete blood count, blood urea nitrogen, creatinine, electrolytes, thyroid function tests, and comprehensive exercise testing should be obtained. Once the cause of the dyspnea is identified and a diagnosis made, treatment can be implemented to improve the patient’s medical condition and decrease the risk of perioperative complications. (175, Figure 13-6)
53. Yes, renal insufficiency is the strongest predictor of perioperative worsening of renal function. It is also equal to CAD as a risk factor for perioperative cardiac complications. (175)
54. Dialysis should be performed within 24 hours of surgery, but not immediately before to avoid acute volume depletion and electrolyte alterations. (175)
55. If the potassium level is less than 6 mEq/dL and within the range of a patient’s established levels, then chronic hyperkalemia may not need to be corrected. (175)
56. Radiocontrast medium transiently decreases the glomerular filtration rate (GFR) in almost all patients, but patients with diabetes or renal insufficiency are at highest risk. (175)
57. The risk of renal injury from radiocontrast medium may be reduced by alkalinizing renal tubular fluid with sodium bicarbonate or by simple hydration in patients with a GFR less than 60 mL/kg/min. (175)
58. Perioperative glucose control in diabetic patients focuses on preventing hypoglycemia during fasting, and preventing extreme hyperglycemia and ketosis. (175-176)
59. Targeting tight glucose control in the immediate perioperative period is not likely to substantially impact outcomes in diabetics having surgery. No data support cancellation of procedures for any increased level of blood glucose or even treatment of high levels for noncardiac surgery cases. Perioperative intervention is warranted if a patient has hypoglycemia (glucose <50 g/dL). Chronically elevated blood sugars are associated with perioperative morbidity. Long-term optimization of diabetes should be considered for high-risk procedures (e.g., joint replacement). (175-176)
60. A BMI of greater than 40 defines extreme obesity. (176)
61. Obesity is associated with OSA, heart failure, diabetes, hypertension, pulmonary hypertension, difficult airway management, and decreased arterial oxygenation. (176)
62. Anemia is a marker for an increased risk of perioperative death, and a predictor of worse short- and long-term outcomes. (176)
63. For an elective procedure with expected blood loss or anticoagulation, anemia should be evaluated preoperatively. If a patient is asymptomatic with chronic anemia and has no history of CAD, and is undergoing a low-risk procedure, then transfusion is not warranted unless the hemoglobin is less than 6 g/dL. If the cause of the anemia is unknown, an evaluation is indicated. A patient with sickle cell disease should be evaluated by a hematologist perioperatively to guide therapy. (176)
64. Pregnant patients may require fetal monitoring, and the potential for preterm labor or delivery should be anticipated. Perioperative plans should be confirmed with the patient’s obstetrician. (176)
65. Patients older than 85 years, and patients with a history of hospital admission within the previous 6 months, are at high risk for postoperative admission after ambulatory surgery. (176)
66. A patient has the right to self-determination in the perioperative period. DNR policies should be reviewed with the patient or the patient’s surrogate before surgery and modified as needed to uphold the patient’s wishes. There are three parts to the perioperative DNR (A, B, and C). Choice A is full attempt at resuscitation. This choice requests full suspension of existing directives during the anesthetic and immediate postoperative period, thereby consenting to the use of any resuscitation procedures to treat clinical events during this time. Choice B is a limited attempt at resuscitation, which may apply or reject certain specific resuscitation procedures (e.g., chest compressions, defibrillation, tracheal intubation). Choice C is a limited attempt at resuscitation defined with regard to the patient’s goals. This choice allows the anesthesiologist and surgical team to use clinical judgment in determining which resuscitation procedures are appropriate in the context of the situation and the patient’s stated goals. (176, Figure 13-7, Table 13-10)
Consultations
67. The purpose of a preoperative consultation is to diagnose, evaluate, and improve a new or poorly controlled condition, and to create a clinical risk profile to help guide the patient, anesthesiologist, and surgeon to make management decisions. (176)
68. A thorough consultation should summarize a patient’s medical problems, condition, and the results of diagnostic tests and provide therapeutic recommendations to help the anesthesiologist provide a safe anesthetic. (176)
Testing
69. No, preoperative testing is not indicated for every patient. Preoperative tests without specific indications lack utility and may lead to patient injury because of unnecessary interventions, delay of surgery, anxiety, and even inappropriate therapies. (176, 178)
70. Preoperative tests should be ordered if the results will impact the decision to proceed with the planned procedure or alter the care plans. Based on a patient’s history (e.g., increased dyspnea on exertion, new onset chest pain, syncope), tests are ordered to establish a diagnosis, evaluate a worsening condition, or aid in preoperative decisions and the management of patients with severe comorbidities. (176, 178)
71. No, age is not an indication for a preoperative ECG. (176, Table 13-11)
72. No, neither preoperative ECGs or chest radiographs predict postoperative complications beyond information available from the patient’s history and examination. (176, 178, Table 13-11)
73. The class I recommendation (procedure is indicated) for ordering a preoperative ECG is for patients with at least one RCRI clinical risk factor (ischemic heart disease, heart failure, cerebrovascular disease, diabetes, renal insufficiency) who are undergoing vascular surgery procedures, and for patients with known coronary heart disease (CHD), peripheral arterial disease, or cerebrovascular disease who are undergoing intermediate-risk surgical procedures. The class IIa recommendations (procedure is reasonable to perform) include patients with no RCRI clinical risk factors who are undergoing vascular surgical procedures. Class IIb recommendations (procedure may be considered) include patients with at least one RCRI clinical risk factor who are undergoing intermediate-risk procedures. Class III recommendations (procedure should not be performed because it is not helpful) include asymptomatic patients undergoing low-risk surgical procedures. (176, 178, Table 13-11)
74. Pregnancy testing should be offered to women. Some facilities make it mandatory before anesthesia; other facilities allow women to decline testing. (178, Table 13-12)
75. The recommendations are to check the following: albumin level if a patient has anasarca, liver disease, malnutrition, or malabsorption; a complete blood count (CBC) with platelets if there is alcohol abuse, anemia, dyspnea, hepatic or renal disease, malignancy, malnutrition, personal history of bleeding, poor exercise tolerance, or recent chemotherapy or radiation therapy; creatinine level if the patient has renal disease; chest radiograph if the patient has an active, acute, or chronic pulmonary symptom such as a cough, dyspnea, abnormal unexplained physical findings on chest examination, decompensated heart failure, malignancy within the thorax, or radiation therapy (to chest, breasts, lungs, thorax); an ECG if there is alcohol abuse, an active cardiac condition, an ICD, OSA, pacemaker, pulmonary hypertension, radiation therapy, severe obesity, syncope, or use of amiodarone or digoxin; electrolytes if there is alcohol abuse, cardiovascular, hepatic, renal or thyroid disease, diabetes, malnutrition, or use of digoxin or diuretics; glucose level if the patient has diabetes, is severely obese, or uses steroids; liver function tests (LFTs) if there is a history of alcohol abuse, hepatic disease, recent hepatitis exposure, or an undiagnosed bleeding disorder; a platelet count if there is a history of alcohol abuse, hepatic disease, bleeding disorder, hematologic malignancy, recent chemotherapy or radiation therapy, or thrombocytopenia; a prothrombin time (PT) if there is a history of alcohol abuse, hepatic disease, malnutrition, bleeding disorder (personal or familial), or use of warfarin; a partial thromboplastin time if there is a bleeding disorder (personal or familial), undiagnosed hypercoagulable state, or use of unfractionated heparin; thyroid-stimulating hormone, triiodothyronine, and thyroxine test if there is a goiter, thyroid disease, unexplained dyspnea, fatigue, palpitations, or tachycardia; and a urinalysis if a urinary tract infection is suspected. (178, Table 13-2)
76. A creatinine level should be checked within 3 months if a patient is to receive an injection of contrast dye. A hemoglobin/hematocrit should be checked if the surgery has the potential for significant blood loss, and a type and screen should be obtained if there is a likelihood of transfusion. On the day of surgery it may be useful to obtain a potassium level in a patient with end-stage renal disease, and a glucose determination in a patient with diabetes, although no absolute level of either potassium or glucose has been determined to preclude surgery and anesthesia. The benefits of the procedure must be balanced against the risk of proceeding in a patient with abnormal results. An ECG is indicated if the patient has an active cardiac condition such as decompensated heart failure, arrhythmia, chest pain, or murmur. (178, Table 13-13)
Medications
77. Perioperative medications should be evaluated on a case by case basis. Generally, cardiac medications, antihypertensive drugs, and nonloop diuretics when taken for hypertension are continued preoperatively. If ACEIs or ARBs are continued, doses of induction and other anesthetic drugs may be altered, and vasopressin should be available to prevent or mitigate hypotension. (178-184, Table 13-14)
78. There are class I recommendations that BB should be continued preoperatively in patients who take them to treat angina, symptomatic arrhythmias, or hypertension. (179, Table 13-14, Table 13-15)
79. Minimizing risk for high-risk patients includes postponing elective surgery to optimize BB and statin therapy. (179)
80. Statins reduce the length of hospital stay, risk of stroke, renal dysfunction, myocardial infarction, and death. Serious consideration should be given to starting a statin if the patient has risk factors for or has known atherosclerotic disease. (179)
81. Abruptly stopping statins may be associated with an increased risk, including death. (179)
82. According to the American Society of Regional Anesthesia (ASRA), neuraxial and peripheral anesthesia is safe for patients taking aspirin. However, since the risk of spinal hematoma is unknown for patients taking clopidogrel, ASRA guidelines suggest discontinuation of clopidogrel 7 days before a planned neuraxial blockade. (180)
83. Yes, antidepressants, antianxiety, and psychiatric medications including MAOIs should be continued preoperatively. Anesthesia management may need to be altered for patients taking MAOIs. (183, Table 13-14)
84. Continuing ACEIs or ARBs prior to surgery may contribute to hypotension under anesthesia. These medications may be discontinued 12 to 24 hours before surgery if taken only for hypertension, especially if the surgical procedure will be lengthy; there will be significant blood loss or fluid shifts; or planned administration of general anesthesia. Also, if the patient is on multiple antihypertensive medications and has well-controlled blood pressure, ACEi or ARBs may be considered for discontinuation 12 to 24 hours before the procedure. (178, Table 13-14)
85. LMWH is discontinued 12 to 24 hours (12 hours if prophylactic dosing 0.5 mg/kg/day, 24 hours if therapeutic dosing 1 mg/kg/day) before procedures with a risk of bleeding or planned neuraxial blockade. (180, Table 13-16)
86. If the INR is 2 to 3, warfarin administration should be stopped 5 days before surgery (unless the procedure is minor such as cataract surgery without bulbar block) to allow the INR to decrease to within reference limits. (180, Table 13-14, Table 13-16)
87. If the INR is measured a day or two before surgery and is greater than 1.8, a small dose of vitamin K (1 to 5 mg orally or subcutaneously) can reverse anticoagulation. (180, Table 13-16)
88. Patients on warfarin should be bridged with LMWH perioperatively if they have had an acute arterial or venous thromboembolism 1 to 3 months before an operation, if the procedure cannot be postponed, if they have a mechanical heart valve, or if they have high-risk hypercoagulable states. (180, Table 13-16)
89. LMWH is typically contraindicated in patients with creatinine clearance less than 40 mL/min, body weight greater than 150 kg, porcine allergy, heparin-induced thrombocytopenia, or patients with a history of bleeding complications while on LMWH. (180, Table 13-16)
90. Type 1 diabetics have an absolute insulin deficiency and require insulin to prevent ketoacidosis even if they are not hyperglycemic. Type 2 diabetics are often insulin-resistant and prone to extreme hyperglycemia. Both type 1 and type 2 diabetics should discontinue intermittent short-acting regular insulin with the exception of the insulin pump. The insulin pump should be continued at the lowest basal rate, which is generally the nighttime dose. Insulin should be discontinued if the blood sugar level is less than 100. Type 1 diabetics should take half of their usual intermediate- to long-acting morning insulin (lente or NPH) the day of surgery to avoid ketoacidosis. Type 2 diabetics take none or up to a half dose of intermediate- to long-acting insulin (lente or NPH) or a combination of a 70/30 preparation insulin on the day of surgery. (180-182, Table 13-14)
91. Yes, glargine should be continued on the day of surgery, but the dose should be decreased if it is 1 unit/kg or more. (182, Table 13-14)
92. No, metformin does not need to be discontinued before the day of surgery and will not cause hypoglycemia during fasting periods of 1 to 2 days. There is no risk of lactic acidosis with metformin in patients with functioning liver and kidneys. Metformin is not administered postoperatively until the risk of lactic acidosis has passed. (182-183, Table 13-14)
93. Yes, to avoid potential hypoglycemia in fasting patients from some oral agents, these medications are generally held on the day of surgery. (182-183, Table 13-14)
94. On the day of surgery patients should continue asthma medications, birth control pills, cardiac medications, triamterine and hydrochlorothiazide if used for hypertension (while loop diuretics are typically withheld), eye drops, gastrointestinal reflux medications, seizure medications, steroids (oral or inhaled), thyroid medications, and autoimmune medications such as methotrexate if there is no risk of renal failure (while entanercept, infliximab, and adalimumab are generally discontinued). Patients may continue COX-2 inhibitors (unless the surgeon is concerned about bone healing), estrogen compounds when used for birth control or cancer therapy, and narcotics for pain or addiction. (178-184, Table 13-14, Table 13-15)
95. Herbals and nonvitamin supplements should be discontinued 7 to 14 days before surgery. The administration of nonsteroidal antiinflammatory drugs should be discontinued 48 hours before surgery. Topical creams, ointments, and Viagra should be discontinued 24 hours before surgery. Vitamins, minerals, and iron should not be taken on the day of surgery. Sildenafil if taken for right heart failure or pulmonary hypertension should be continued perioperatively. (178-184, Table 13-14)
96. Valerian is a central nervous system depressant, which may cause a benzodiazepine-like withdrawal when abruptly discontinued. It is safest to taper this medication. (183)
97. Herbal therapy alone is not a contraindication to neuraxial or regional anesthesia per ASRA guidelines. (183)
98. MAOIs have a long duration of action, approximately 3 weeks. Discontinuation of MAOIs may produce severe depression or result in suicide. The safest alternative is to continue MAOIs and adjust the anesthetic plan. (183)
99. Patients should continue any narcotic pain medications to prevent withdrawal symptoms and discomfort. Anxiolytics are continued as well. Drugs used to treat addiction, such as methadone or nicotine-replacement therapies, are also continued. (183-184, Table 13-14)
100. Yes, patients taking oral steroids should continue the steroid on the day of surgery. (183-184)
101. A normal daily adrenal output of cortisol is 30 mg, which is equivalent to 5 to 7.5 mg of prednisone. (183)
102. The hypothalamic-pituitary axis (HPA) may be suppressed in patients taking 5 to 20 mg/day of prednisone or its equivalent for more than 3 weeks. The HPA is usually suppressed with more than 20 mg/day of prednisone for more than 3 weeks. The risk of adrenal insufficiency remains for up to 1 year after the cessation of high-dose steroids. A patient with a suppressed HPA may need supplemental perioperative steroids if his or her HPA cannot increase the output of glucocorticoids during the period of surgery, trauma, or infection. (183)
103. High-dose steroids are associated with infections, psychosis, poor wound healing, and hyperglycemia. (183)
104. For a minor procedure (e.g., inguinal herniorrhaphy), the target hydrocortisone equivalent is 25 mg/day, so additional supplementation is not necessary and the patient should just take their usual daily dose of steroid. For a moderate stress surgical procedure (colon resection, total joint replacement, lower extremity revascularization) the target hydrocortisone equivalent is 50 to 75 mg/day for 1 to 2 days. The patient should take their usual daily dose of steroid, receive 50 mg hydrocortisone intraoperatively, then 20 mg hydrocortisone every 8 hours through postoperative day 1, then resume their home dosing of steroid. If a major surgery is planned (pancreatoduodenectomy, esophagectomy), then the target hydrocortisone equivalent is 100 to 150 mg/day for 2 to 3 days. The patient should take their usual daily dose of steroid, receive 50 mg hydrocortisone intraoperatively, and continue with 50 mg hydrocortisone every 8 hours through postoperative day 2. After postoperative day 2, they should then resume their home dose of steroid. (183, Table 13-17)
105. Premedication for anxious patients before surgery may include a short course of benzodiazepines in the days preceding surgery and the day of the operation, or opioids in patients with preoperative pain or discomfort associated with regional anesthesia or insertion of invasive monitors before the induction of anesthesia. (183-184, Table 13-18)
106. Patients at risk for PONV may be prescribed a scopolamine patch to be placed 2 to 4 hours preoperatively. Scopolamine is contraindicated in patients with closed angle glaucoma. (184, Table 13-18)
107. Patients at increased risk for pulmonary aspiration include parturient patients, patients with intraabdominal masses, nonfasting individuals, patients with an incompetent lower esophageal sphincter with reflux, symptomatic hiatal hernia, diabetes mellitus, gastric motility disorders, anticipated difficult airway, bowel obstruction, and ascites. Alteration of gastric contents to increase pH and limit the severity of potential pulmonary aspiration can be achieved with H2 antagonists, proton pump inhibitors, and non-particulate antacids, along with prokinetic agents to stimulate gastric emptying. (184)
Fasting
108. Up to 8 hours prior to surgery, any food or fluid may be consumed. For patients without risk factors for pulmonary aspiration (see question 107) the following applies: up to 6 hours before surgery, the patient may have a light meal (toast and clear liquids), infant formula, or nonhuman milk; up to 4 hours before surgery, breast milk may be consumed; up to 2 hours before surgery, the patient may take clear liquids without milk, pulp, or alcohol. During the 2 hours before surgery, no solids or liquids may be taken orally. If the patient has risk factors for pulmonary aspiration, no food or fluid should be consumed within 8 hours of the surgery. (184, Table 13-19)
Formulation of anesthetic plan, assessment of risk, and informed consent
109. The anesthesiologist considers the patient’s coexisting diseases, the site of surgery, position of the patient during surgery, risk of aspiration, age of the patient, patient cooperation and preference, anticipated ease of airway management, coagulation status, and the patient’s previous response to anesthesia. (185, Table 13-20)
110. With general anesthesia, side effects that occur frequently but have minimal consequences include oral or dental damage, sore throat, hoarseness, postoperative nausea/vomiting, drowsiness/confusion, and urinary retention. Side effects of general anesthesia that occur infrequently but have severe consequences include intraoperative awareness, visual loss, aspiration, organ failure, malignant hyperthermia, drug reactions, failure to wake up/recover, and death. (Table 13-22)
111. With regional anesthesia, side effects that occur frequently but with minimal impact include prolonged numbness/weakness, postdural puncture headache, and failure of technique. Side effects of regional anesthesia that occur infrequently but with severe consequences include bleeding, infection, nerve damage/paralysis, persistent numbness/weakness, seizures, coma, and death. (Table 13-22)
112. Informed consent involves the indications for the treatment in terms a layperson can understand, and elucidation of alternatives. When an anesthesiologist obtains informed consent prior to the day of surgery, anxiety is lower in patients before their operation. (185)
