Gastrointestinal system
A Anal fistulotomy and fistulectomy
Most perianal fistulas arise as a result of infection within the anal glands located at the dentate line (cryptoglandular fistula). Fistulas may also arise as the result of trauma, Crohn’s disease, inflammatory processes within the peritoneal cavity, neoplasms, or radiation therapy. The ultimate treatment is determined by the cause and the anatomic course of the fistula and can include fistulotomy and fistulectomy. The primary goal is palliation, specifically to drain abscesses and prevent their recurrence. This is often accomplished by placing a Silastic seton (a ligature placed around the sphincter muscles) around the fistula tract and leaving it in place indefinitely. In the absence of active Crohn’s disease in the rectum, attempts at fistula cure may be undertaken.
a) History and physical examination
(1) Respiratory: A careful evaluation of respiratory status is important. If the patient has significant respiratory disease, the lithotomy position is better tolerated than the prone or jackknife positions.
(2) Musculoskeletal: Pain is likely at the surgical site and should be considered when positioning the patient for anesthetic induction. (If the patient has pain while sitting, regional anesthesia should be performed with the patient in the lateral decubitus position.)
(3) Hematologic: If regional anesthesia is planned and the patient is taking acetylsalicylic acids, nonsteroidal anti-inflammatory drugs (NSAIDs), or dipyridamole, check the platelet count and bleeding time.
General anesthesia, local anesthesia with sedation, and spinal or epidural techniques may be used.
a) Induction: Standard. Procedures done with the patient in the jackknife or prone position may require endotracheal intubation for airway control if a regional technique is not performed.
(2) Position: Use chest support or bolster to optimize ventilation in the jackknife position; take care in positioning the patient’s extremities and genitals after turning the patient into the jackknife position. Avoid pressure on the eyes and ears after turning the patient. Avoid stretching the brachial plexus. Limit abduction to 90 degrees.
c) Emergence: No special considerations are needed. The patient is extubated awake and after return of airway reflexes.
B Cholecystectomy
Surgery of the upper abdomen is used in the treatment of gallstones and other diseases of the gallbladder. Open cholecystectomy is performed in patients with adhesions, previous surgical procedures, infection, or major medical problems. An intraoperative cholangiogram may be done to determine if there are gallstones present within the biliary tree. The mortality rate for elective cholecystectomy is less than 0.5%. In patients older than 70 years of age, the mortality rate rises to 2% to 3%, mostly because of preexisting cardiopulmonary disease. Presently, the surgical approach used during cholecystectomy is laparoscopic.
a) History and physical examination
(2) Gastrointestinal assessment: Pain is localized in the right subcostal region. The patient may experience referred pain in the back at the shoulder level. Anorexia, nausea, and vomiting are common. Infection and fever are rare.
b) Diagnostic tests: These are as indicated by the patient’s history and medical condition.
c) Preoperative medication and IV therapy
(1) Use an antimicrobial to prevent bacteremia.
(2) Narcotics must be used with caution to minimize potential spasm in the biliary tract and sphincter of Oddi. Medications used to inhibit sphincter of Oddi spasm include nitrates, glucagon, Narcan, and anticholinergics.
(3) Use a single, large-bore (18-gauge) IV catheter with fluid replacement. Patients may be dehydrated and require generous IV hydration before induction.
(4) Use prophylactic antiemetics and aspiration prophylaxis.
General endotracheal anesthesia with muscle relaxation is used.
a) Induction: Rapid-sequence induction with oral endotracheal intubation if the patient is considered to have a full stomach
(2) Muscle relaxation per abdominal surgery
(4) Potential intraoperative complications include hemorrhage, gas embolism, symptomatic bradycardia, pneumothorax, and subcutaneous emphysema.
c) Emergence: Awake extubation after airway reflexes are adequate
C Colectomy
Colectomy is performed most commonly for adenocarcinomas and diverticulosis. Other indications include penetrating trauma, ulcerative and ischemic colitis, volvulus, and inflammatory bowel disease.
2. Preoperative assessment and patient preparation
a) History and physical examination: Assess hydration status, nutritional level, and electrolyte state.
b) Diagnostic tests: These are as indicated by the patient’s condition.
c) Preoperative medication and IV therapy
(1) Patients may be receiving steroid therapy or immunosuppressant drugs.
(2) Bowel preparation is usually indicated with electrolyte preparations except in emergencies.
(3) Expect fluid shifts requiring moderate to large fluid resuscitation. Two large-bore IV access tubes are indicated.
(4) IV antibiotic therapy should be initiated before incision
a) Epidural (T4 level) with “light” general anesthetic
b) General anesthesia with oral endotracheal tube (most common)
a) Induction: Consider the possibility of a full stomach; rapid-sequence induction may be indicated. If the colectomy is performed for perforation of the bowel from any cause, septicemia must be suspected. Extreme hemodynamic variability with severe hypotension is possible.
c) Emergence: This involves awake extubation after rapid-sequence induction or placement of a nasogastric tube.
D Colonoscopy
Colonoscopy is used to examine the colon and rectum to diagnose inflammatory bowel disease, including ulcerative colitis and granulomatous colitis. Polyps can be removed through the colonoscope. The colonoscope is also helpful in diagnosing or locating the source of gastrointestinal bleeding; a biopsy of lesions suspected to be malignant may be performed.
2. Preoperative assessment and patient preparation
a) History and physical examination: Assess the patient’s hydration status, nutritional level, and electrolyte state.
b) Diagnostic tests: These are as indicated by the patient’s condition.
c) Preoperative medication and IV therapy
(1) Patients may be receiving steroid therapy or immunosuppressants.
(2) Bowel preparation is required for visualization of the mucosa. Colon electrolyte lavage preparations (Colyte, GoLYTELY) are given the night before the procedure.
(3) One 18-gauge IV tube is used; adequate fluid replacement is ensured.
(4) The patient is lightly sedated with midazolam because the procedure lasts less than 30 minutes and is an outpatient procedure.
a) Monitoring equipment: Standard
c) Position: Left lateral decubitus; position changes sometimes required to aid advancement of the scope at the descending sigmoid colon junction and splenic fixture.
Complications of the procedure include perforation of the bowel, abdominal pain and distention, rectal bleeding, fever, and mucopurulent drainage.
E Esophageal resection
Esophagectomy is commonly performed for malignant disease of the middle and lower third of the esophagus. It may also be indicated for Barrett’s esophagus (peptic ulcer of the lower esophagus) and for peptic strictures that do not respond to dilation and end-stage achalasia. Whereas lesions in the lower third are usually approached through a left thoracoabdominal incision, middle-third lesions are best approached by the abdomen and thoracotomy. Resections of the esophagogastric junction for malignant disease are best performed through a left thoracoabdominal approach in which a portion of the proximal stomach is removed along with a celiac node dissection. In a transhiatal approach, the esophagus is exposed through abdominal and neck incisions.
Total esophagectomy may be done through an abdominal and right thoracotomy approach with colonic interposition and anastomosis in the neck. Either the right or the left side of the colon can be mobilized for interposition. Both depend on the middle colic artery and the marginal artery of the colon for their vascular supply.
a) History and physical examination
(1) Cardiovascular: The patient may be hypovolemic and malnourished from dysphagia or anorexia. Chemotherapeutic drugs (daunorubicin, doxorubicin [Adriamycin]) may cause cardiomyopathy. Chronic alcohol abuse may also produce toxic cardiomyopathy.
(2) Respiratory: A history of gastric reflux suggests the possibility of recurrent aspiration pneumonia, decreased pulmonary reserve, and increased risk of regurgitation and aspiration during anesthetic induction. If a thoracic approach is planned, the patient should be evaluated to ensure that one-lung ventilation can be tolerated. Patients with upper esophageal tumors or mediastinal lymphadenopathy may need tracheal or bronchial compression. Difficult airway and respiratory compromise are possible. Many patients with esophageal cancer have a long history of smoking, with consequent respiratory impairment.
(a) Chemotherapeutic drugs (bleomycin) may cause pulmonary toxicity that can worsen with high concentrations of oxygen.
(b) Pulmonary function tests and arterial blood gases can be helpful in predicting the likelihood of perioperative pulmonary complications and whether the patient may require postoperative mechanical ventilation. Patients with baseline hypoxemia or hypercarbia on room air arterial blood gases have a higher likelihood of postoperative complications and a greater need for postoperative ventilatory support. Severe restrictive or obstructive lung disease will also increase the chance of pulmonary morbidity in the perioperative period.
(1) Laboratory tests: Type and cross-match packed red blood cells, electrolytes, glucose, blood urea nitrogen, creatinine, liver function test, complete blood count, and platelet count. Prothrombin time, partial thromboplastin time, urinalysis, arterial blood gases, and other tests as indicated by the patient’s history and physical examination.
(2) Diagnostic tests: Chest radiography, electrocardiography, pulmonary function tests, and other tests are as indicated by the patient’s history and physical examination. If congestive heart failure or cardiomyopathy is suspected, consider cardiac or medical consultations.
(3) Medications: For premedication, consider aspiration prophylaxis.
General endotracheal anesthesia with or without epidural anesthetic for postoperative analgesia is administered. If the thoracic or abdominothoracic approach is used, placement of a double-lumen tube is indicated because one-lung anesthesia provides excellent surgical exposure. If the patient is clinically hypovolemic, intravascular volume should be restored before induction and carefully titrate the induction dose of sedative–hypnotic agents.
(1) Patients with esophageal disease are often at risk for pulmonary aspiration; therefore, rapid-sequence induction is indicated.
(2) If a difficult airway is anticipated, awake intubation can be done using a fiberoptic bronchoscope.
(1) Standard maintenance uses a narcotic, inhalation agent, or both. Avoid nitrous oxide.
(2) A combined technique with general and epidural anesthesia may be used. If epidural opiates are used for postoperative analgesia, a loading dose should be administered at least 1 hour before the conclusion of surgery.
(3) Position: The patient is supine, with checked and padded pressure points. Avoid stretching the brachial plexus. Limit abduction to 90 degrees. If the lateral decubitus position is used, an axillary roll and arm holder are needed. Check pressure points, including ears, eyes, and genitals. Check radial pulses to ensure correct placement of the axillary roll (a misplaced axillary roll will compromise distal pulses). Problems that can arise include brachial plexus injuries and damage to soft tissues, ears, eyes, and genitals from malpositioning.
(4) Maintain normal volume status euvolemia as significant third spacing can occur
(5) Transient compression of the myocardium can occur (i.e., thoracic approach) and cause dysrhythmias or hypotension. An arterial line is recommended to maintain blood pressure.
c) Emergence: The decision to extubate at the end of surgery depends on the patient’s underlying cardiopulmonary status and the extent of the surgical procedure. The patient should be hemodynamically stable, warm, alert, cooperative, and fully reversed from any muscle relaxants before extubation. With patients who require postoperative ventilation, the double-lumen tube should be changed to a single-lumen endotracheal tube before transport to the postanesthesia intensive care unit. Weaning from mechanical ventilation should begin when the patient is awake and cooperative, is able to protect the airway, and has adequate pulmonary function.
a) For atelectasis or aspiration, recover the patient in Fowler position.
b) Hemorrhage: Check coagulation times; replace factors as necessary.
c) Pneumothorax or hemothorax: Decreased partial oxygen pressure, increased partial carbon dioxide pressure, wheezing, and coughing are noted; confirm with chest radiography and institute chest tube drainage as necessary. In an emergency (tension pneumothorax), use needle aspiration, supportive treatment, oxygen, vasopressors, endotracheal intubation, and positive-pressure ventilation.
d) Hypoxemia or hypoventilation: Ensure adequate analgesia and supplemental oxygen. Determine the cause.
e) Esophageal anastomotic leak: Begin surgical repair for an esophageal anastomotic leak.
f) Pain management: Patient-controlled analgesia or epidural analgesia is used; the patient should recover in the intensive care unit or in a hospital unit accustomed to treating the side effects of epidural opiates (respiratory depression, breakthrough pain, nausea, and pruritus).
g) Recurrent laryngeal nerve injury: hoarse voice, respiratory distress
F Esophagoscopy and gastroscopy
Flexible, diagnostic esophagogastroduodenoscopy, a common procedure in pediatrics, is usually performed with the patient under deep sedation in an endoscopy suite or special procedure area. Rigid esophagoscopy is usually performed for therapeutic indications, such as removal of a foreign body, dilation of an esophageal stricture, or injection of varices. The procedure is similar for each diagnosis and is generally performed with endotracheal intubation. Foreign body removal is normally a short procedure, but dilation and variceal injection can be prolonged and may require multiple insertions or removals of the endoscope. Compression of the trachea distal to the endotracheal tube by the rigid esophagoscope is common.
Esophagoscopy for foreign body removal is usually performed in healthy infants and children, although esophageal lodging of a foreign body can occur in any age group. All of these patients should be treated with full-stomach precautions. Esophageal dilation usually is performed in two distinct patient populations: those with prior tracheoesophageal fistula repair and those with prior ingestion of a caustic substance.
a) History and physical examination
(1) Cardiovascular: Patients with tracheoesophageal fistulas may have congenital cardiac anomalies.
(2) Respiratory: Patients with prior caustic ingestion may have a history of pulmonary aspiration, with resultant chemical pneumonitis, fibrosis, or both. Prolonged intubation after tracheoesophageal fistula repair may lead to subglottic stenosis. Check any recent anesthesia records for endotracheal intubation.
(1) Laboratory tests: As indicated per the patient’s history and physical examination
(2) Diagnostic tests: As indicated per history and physical examination
(3) Medications: For foreign body removal, IV access may be necessary before induction. No premedication is used if the patient is younger than 1 year old.
General anesthesia with an endotracheal tube. Room temperature can be maintained at 65° to 70° F as long as the patient is covered.
a) Induction: Rapid-sequence induction is usually appropriate for this patient population unless the patient is presenting for dilation alone and has no evidence to suggest reflux.
(1) Maintain anesthesia with a volatile agent, nitrous oxide, and oxygen. Opiates are unnecessary because postprocedural pain is negligible. Maintain neuromuscular blockade. Movement must be avoided, particularly with rigid esophagoscopy. Consider the use of dexamethasone to treat airway edema.
(2) Position: Supine. Pressure points are checked. Arms are positioned at less than 90°. Avoid stretching the brachial plexus.
(3) Warming modalities for pediatric patients: Increased room temperature, warming blankets, and a Humidivent.
c) Emergence: Extubate when the patient is fully awake. Do not attempt reversal of neuromuscular blockade until first twitch of train-of-four has returned.
G Gastrectomy
Total gastrectomy is annually performed for gastric cancer.
2. Preoperative assessment and patient preparation
a) History and physical: Assess fluid and hydration status. The patient may be vomiting or bleeding or may have anorexia.
a) Induction: Most patients are considered to have full stomachs; therefore, rapid-sequence induction with cricoid pressure.
(1) Muscle relaxation is required.
(2) A narcotic or inhalation agent (or both) is administered.
(3) Closely monitor hydration status and blood loss.
(4) Avoid nitrous oxide to minimize gastric or colonic distention.
(5) A nasogastric tube may be inserted.
(6) Prophylactic antiemetics because of the risk of postoperative nausea and vomiting
c) Emergence: Awake extubation is performed after rapid-sequence induction or placement of a nasogastric tube.
Pain may lead to hypoventilation, reduced cough, splinting, and atelectasis.
H Gastrostomy
A gastrostomy involves the placement of a semipermanent tube through the abdominal wall directly into the stomach. These tubes are used for gastric decompression or for feeding. It may be temporary or permanent. A percutaneous endoscopic gastrostomy is often performed. Feeding gastrostomy tubes are indicated in patients unable to feed by mouth but able to absorb enteral nutrition, such as patients with advanced malignancy and intestinal obstruction, inadequate oral intake, and neurologic impairment.
Patients undergoing gastrostomy may have neurologic impairment caused by a stroke and head injury. This compromises their ability to handle oral secretions and increases their risk for aspiration.
a) History and physical examination
(1) Cardiac: Patients are likely to be hypovolemic secondary to chronically poor oral intake and malnutrition.
(2) Respiratory: Patients may have difficulty swallowing and inadequate laryngeal reflexes, placing them at high risk for aspiration of gastric contents and associated pneumonitis. Hypoxemia and decreased pulmonary reserve can be caused by prior pulmonary infections.
(3) Neurologic: The patient is often neurologically impaired and debilitated.
(4) Renal: Long-term indwelling urinary catheters increase the risk of infection.
IV sedation or monitored anesthesia care with local anesthesia is used.
(1) If general anesthesia is planned, use rapid-sequence induction with cricoid pressure.
(2) Titrate narcotics (fentanyl) or benzodiazepines (midazolam) as indicated.
c) Emergence: Tracheal extubation is performed after the return of protective laryngeal reflexes.
Mild to moderate postoperative pain intensity may be controlled with parenteral narcotics or intercostal blocks. Postoperative complications include aspiration pneumonia, wound infection, and atelectasis.
I Hemorrhoidectomy
Hemorrhoids are masses of vascular tissue found in the anal canal. Internal hemorrhoids are found above the pectinate line, arise from the superior hemorrhoidal venous plexus, and are covered with mucosa. External hemorrhoids are found below the pectinate line, arise from the inferior hemorrhoidal venous plexus, and are covered by anoderm and perianal skin. Treatment includes hemorrhoidectomy.
2. Preoperative assessment and patient preparation
a) History and physical examination: Signs include bright red blood on toilet paper or the surface of the stool, iron-deficiency anemia, a prolapsed mass of tissue that protrudes from the anus, and thrombosis (blood clot within the hemorrhoidal vein) causing pain.
a) Regional anesthesia, local anesthesia with sedation, or general anesthesia
b) Regional blockade: S2-S5 sensory level block
c) General anesthesia: Mask or laryngeal mask airway in lithotomy position (endotracheal intubation necessary for prone position)
(1) Prone: General anesthesia induction is performed while the patient is on the stretcher.
(2) Position the patient on the operating table with adequate support and padding of the extremities, head, and neck.
b) Maintenance: General anesthesia: An adequate depth of anesthesia is required to relax the anal sphincter. Angiospasm during anal dilation can occur.
c) Emergence: If the prone position is used and general anesthesia is administered, patients are repositioned onto the stretcher before emergence.
Bearing down to void will be painful; keep fluids to a minimum.
J Herniorrhaphy
Inguinal hernias are defects in the transverse abdominal layer; a direct hernia comes through the posterior wall of the inguinal canal, and an indirect hernia comes through the internal inguinal ring. Femoral hernia occurs when the hernia sac is exposed as it exits the preperitoneal space through the femoral canal. Incisional hernias can occur after any abdominal incision, but they are most common after midline incisions. Factors leading to herniation are ischemia, wound infection, trauma, and inadequate suturing. Treatment is with herniorrhaphy.
Predisposing factors for hernia often include increased abdominal pressure secondary to chronic cough, bladder outlet obstruction, constipation, pregnancy, vomiting, and acute or chronic muscular effort. The patient population may range from premature infants to elderly adults, with the possibility of various medical problems.
a) History and physical examination: These are as indicated by the patient’s condition.
(1) Musculoskeletal: Pain is likely in the area of the hernia; evaluate bony landmarks if regional anesthesia is planned.
(2) Hematologic: If regional anesthesia is planned, check the patient’s coagulation status.
(3) Gastrointestinal: Hernias may become incarcerated, obstructed, or strangulated and can result in septicemia requiring emergency surgery. Fluid and electrolyte imbalance should be assessed.
General, regional, and local anesthesia with sedation are all appropriate. The choice depends on such factors as site of incision, the patient’s physical status, and the preference of both the patient and surgeon. General anesthesia may be preferred for incisions made above T8. Profound muscle relaxation may be needed for exploration and repair. If a laparoscopic approach is desired, general anesthesia and intubation are required.
a) Standard induction: General anesthesia by mask or laryngeal mask airway may be suitable for the patient with a simple chronic hernia. If there is obstruction, incarceration, or strangulation, rapid-sequence induction with endotracheal intubation is indicated. General endotracheal anesthesia is indicated in the patient with wound dehiscence.
(1) Standard: Muscle relaxants may be necessary to facilitate surgical repair.
(2) Position: While the patient is supine, pressure points should be checked and padded. Avoid stretching the brachial plexus. Limit abduction to 90 degrees.
c) Emergence: Consider extubating the trachea while the patient is still anesthetized to prevent coughing and straining. Patients who are at risk for pulmonary aspiration and who require awake extubation after rapid-sequence induction are not candidates for deep extubation.
a) Wound dehiscence may occur with coughing or straining.
b) Urinary retention: Patients with urinary retention may require intermittent catheterization until urinary function resumes.
c) Pain management: Surgical field block or regional anesthesia should provide sufficient analgesia postoperatively.
K Laparoscopic appendectomy
Appendectomy is performed for acute appendicitis, and a laparoscopic approach is most commonly used.
2. Preoperative assessment and patient preparation
a) History and physical examination
(1) Gastrointestinal: Patients point to localized pain at McBurney point, which is midway between the iliac crest and umbilicus; rebound tenderness, muscle rigidity, and abdominal guarding are noted.
(2) Pregnancy: Alder sign is used to differentiate between uterine and appendiceal pain. The pain is localized with the patient supine. The patient then lies on his or her left side. If the area of pain shifts to the left, it is presumed to be uterine.
(1) The white blood cell count is elevated, with a shift to the left: 10,000 to 16,000 mm3; 75% neutrophils. Increased body temperature may indicate ruptured appendix and septicemia.
(2) Urinalysis shows a small number of erythrocytes and leukocytes.
(3) Computed tomography and abdominal radiography are used.
(4) Other laboratory tests include electrolytes, glucose, hemoglobin, and hematocrit. Perform tests as indicated from the history and physical examination. Vomiting will contribute to volume depletion and electrolyte abnormalities.
General anesthesia: Endotracheal intubation required
a) IV rehydration is necessary
(1) Use general anesthesia with rapid-sequence induction because patients may have a nasogastric tube or are considered to have a full stomach (emergency).
(2) In the pregnant patient, special care should be taken to prevent aspiration pneumonitis.
d) Emergence: Awake extubation secondary to rapid-sequence induction
L Laparoscopic cholecystectomy
Laparoscopic cholecystectomy is a minimally invasive surgical procedure used in the treatment of gallstones and diseases of the gallbladder. The laparoscopic approach is contraindicated in uncorrectable coagulopathy, severe chronic obstructive pulmonary disease, and severe cardiac disease secondary to increased abdominal pressures.
2. Preoperative assessment and patient preparation
a) History and physical examination: These are as indicated by the patient’s history and medical condition
b) Diagnostic tests: These are as indicated by the patient’s history and medical condition.
c) Preoperative medication and IV therapy
(1) Preoperative antibiotics are used.
(2) Narcotics must be used with caution to minimize potential spasm in the biliary tract and sphincter of Oddi.
(3) Use a single, large-bore (18-gauge) IV catheter for fluid replacement. Use a fluid warmer.
(4) Administer prophylactic antiemetics and aspiration prophylaxis.
General endotracheal anesthesia with muscle relaxation
a) Induction: Standard or rapid-sequence induction and endotracheal intubation with cricoid pressure is required.
(1) Muscle relaxation with appropriate reversal is used.
(2) The peritoneal cavity is insufflated for surgical exposure. Insufflation with carbon dioxide causes a rise in the carbon dioxide partial pressure.
(3) Controlled ventilation is required. Abdominal insufflation may lead to hypercarbia with inadequate ventilation. Special attention should be paid to possible adjustments in ventilator settings with insufflation and exsufflation.
(4) Basal measurements should be sufficient to control carbon dioxide partial pressure.
(5) Routine insufflation pressure is 15 mmHg (can decrease to 10–12 mmHg). Insufflation leads to increased intraabdominal pressure, increased afterload, and decreased preload. An intraabdominal pressure greater than 20 cm H2O can decrease cardiac output, dramatically increase peak airway pressures, and cause hypotension. Insufflation to a pressure of approximately 15 mmHg is routine.
(6) All maintenance anesthetic drugs may be used. Avoid nitrous oxide secondary to bowel distention, which leads to decreased surgical exposure.
c) Complications include pneumoperitoneum hypercarbia, pneumothorax, pneumomediastinum, endobronchial intubation, decreased blood pressure, hemorrhage, dysrhythmias, visceral injury, hypothermia, and subcutaneous emphysema.
d) Emergence: Awake extubation is performed after the patient’s airway reflexes are adequate.
a) Pain management: This approach offers the benefit of reduced postoperative pain secondary to smaller abdominal incisions. Patients may experience shoulder pain from the pneumoperitoneum, which is usually self-limiting. Use of IV narcotics, ketorolac or other NSAIDs are warranted.
b) Postoperative nausea and vomiting: Antiemetic prophylaxis is used.
M Liver resection
Patients presenting for hepatic surgery may have primary or metastatic tumors from gastrointestinal and other sources. Liver function may be entirely normal in these patients. Hepatocellular carcinoma is common in men older than 50 years and is associated with chronic, active hepatitis B and cirrhosis. Although most major liver resections can be performed by a transabdominal approach, some surgeons prefer a thoracoabdominal approach. The liver is transected by blunt dissection using the Cavitron ultrasonic suction aspirator and argon beam laser coagulator. Newer ablation devices include hydro jet and ultrasonic pulses.
As the principles and techniques of hepatic surgery have evolved, the overall mortality and morbidity rates have improved considerably. Because the normal liver can regenerate, it is possible to resect the right or left lobe along with segments of the contralateral lobe. In patients with cirrhosis, the regeneration process is limited; thus, uninvolved liver should be preserved.
The following preoperative considerations are for patients without hepatic cirrhosis:
a) History and physical examination: These are as indicated by the patient’s history and medical condition.
(1) Laboratory tests: Complete blood count, coagulation profile, liver function test, albumin, creatinine, blood urea nitrogen, blood sugar, bilirubin, and electrolytes are obtained. Perform other tests as indicated by the history and physical examination.
(2) Diagnostic tests: Chest radiography, ultrasonography, computed tomography, and magnetic resonance imaging are used as indicated by the history and physical examination.
(3) Medications: Standard premedication that accounts for the reduced ability of the liver to metabolize drugs is given. Other preoperative medications include antiemetics.
(1) Standard monitoring equipment
(2) Arterial line and central venous pressure as clinically indicated
(3) IV fluids: 14- or 16-gauge IV lines (two) with normal saline at 10 to 20 mL/kg/hr; warmed fluids
(4) Two units of packed red blood cells should be available. Blood loss can be significant, and massive transfusions may be required. Appropriate blood products also include 2 units of fresh-frozen plasma and 10 units of platelets.
4. Perioperative management and anesthetic technique
(1) General endotracheal anesthesia with rapid sequence intubation is used.
(2) Restore intravascular volume before anesthetic induction. If the patient is hemodynamically unstable, consider etomidate (0.2–0.4 mg/kg) or ketamine (1–3 mg/kg).
(2) Combined epidural and general anesthesia: Be prepared to treat hypotension with fluid and vasopressors. General anesthesia is administered to supplement regional anesthesia and for amnesia. Coexisting coagulation abnormalities can increase the risk of epidural hematoma in these patients with preexisting coagulopathies.
(3) Position: The patient is supine, with checked and padded pressure points. Avoid stretching the brachial plexus. Limit abduction to 90 degrees.
(1) For major hepatic resections, the patient is best cared for in an intensive care unit.
(2) Consider keeping the patient mechanically ventilated until the patient’s condition is hemodynamically stable and ventilatory status is optimized.
(3) If surgical resection was minimal, the patient can be extubated awake and after reflexes have returned.
a) Decreased liver function: Patients with normal preoperative liver function may have significant postoperative impairment of liver function secondary to loss of liver mass or surgical trauma.
b) Pulmonary insufficiency (atelectasis, effusion, and pneumonia): More than 90% of patients will develop some form of respiratory complication.
N Liver transplantation
Liver transplantation is the treatment of choice for patients with acute and chronic end-stage liver disease. The liver transplant operation can be divided into three stages: (1) hepatectomy; (2) anhepatic phase, which involves the implantation of the liver; and (3) postrevascularization, which involves hemostasis and reconstruction of the hepatic artery and common bile duct. Hepatectomy can be associated with marked blood loss. Contributing factors include severe coagulopathy, severe portal hypertension, previous surgery in the right upper quadrant, renal failure, uncontrolled sepsis, retransplantation, transfusion reaction, venous bypass–induced fibrinolysis, primary graft nonfunction, and intraoperative vascular complications.
The anhepatic phase may be associated with significant hemodynamic changes. This stage consists of implantation of the liver allograft with or without venovenous bypass. Benefits of using the venovenous bypass system include improved hemodynamics during the anhepatic phase, decreased blood loss, and possible improvement of perioperative renal function. Complications of using the system include pulmonary embolism, air embolism, brachial plexus injury, and wound seroma or infection.
Before revascularization, the liver must be flushed with a cold solution (i.e., albumin 5%) through the portal vein and out the infrahepatic vena cava. The reperfusion of the liver may be the most critical part of the operation. Patients may experience pulmonary hypertension followed by right ventricular failure and profound hypotension. The hepatic artery reconstruction is performed after stabilization of the patient after revascularization. The last part involves hemostasis, removal of the gallbladder, and reconstruction of the bile duct.
Patients requiring liver transplantation often have multiorgan system failure. Because of the emergency nature of the surgery, there may be insufficient time available for customary evaluation and correction of abnormalities.
a) History and physical examination
(1) Cardiovascular: These patients can present with a hyperdynamic state, with increased cardiac output and decreased systemic vascular resistance. Many of these patients present with dysrhythmias, hypertension, pulmonary hypertension, valvular disease, cardiomyopathy (alcoholic disease, hemochromatosis, Wilson disease), and coronary artery disease.
(2) Respiratory: Patients are often hypoxic because of ascites, pleural effusions, atelectasis, ventilation–perfusion mismatch, and pulmonary arteriovenous shunting. This normally results in tachypnea and respiratory alkalosis. Pulmonary infection usually is a contraindication to surgery. Adult respiratory distress syndrome usually is not.
(3) Hepatic: Hepatitis serology and the cause of hepatic failure should be determined. Albumin is usually low, with consequent low plasma oncotic pressure leading to edema and ascites. The magnitude of action and duration of drugs may be unpredictable, although these patients generally have an increased sensitivity to all drugs, and the drug actions are prolonged.
(4) Neurologic: Patients are often encephalopathic and may be in hepatic coma. In fulminant hepatic failure, increased intracranial pressure is common, accounting for 40% mortality (herniation), and may require prompt treatment (e.g., mannitol, hyperventilation).
(5) Gastrointestinal: Portal hypertension, esophageal varices, and coagulopathies increase the risk of gastrointestinal hemorrhage. Gastric emptying is often delayed.
(6) Renal: Patients are often hypervolemic, hyponatremic, and possibly hypokalemic. Calcium is usually normal. Metabolic alkalosis is often present. Preoperative dialysis should be considered.
(7) Endocrine: Patients are often glucose intolerant or diabetic. Hyperaldosteronism may be present.
(8) Hematologic: Patients are often anemic secondary to blood loss or malabsorption. Coagulation is impaired because of decreased hepatic synthesis function, abnormal fibrinogen production, impaired platelets, fibrinolysis, and low-grade disseminated intravascular coagulation.
(1) Laboratory tests: Complete blood count, coagulation profile, liver function tests, albumin, creatinine, blood urea nitrogen, blood sugar, bilirubin, and electrolytes are obtained. Perform other tests as indicated by the history and physical examination.
(2) Diagnostic tests: Chest radiography, pulmonary function tests, electrocardiography, echocardiogram, and cardiac catheterization are obtained.
(3) Medication: Standard premedication and aspiration prophylaxis are used, but the dose may be modified based on the patients preexisting mental and hemodynamic status.
(2) Arterial line, transesophageal echocardiography, central venous pressure, or pulmonary artery catheter as indicated
General anesthesia is used. These patients are challenging to manage during the various stages of the surgery. Hemodynamic instability, massive blood loss, electrolyte imbalance (hypocalcemia, hyperglycemia, hypernatremia, hyperkalemia), and coagulopathy may occur.
(1) Rapid-sequence induction with oral endotracheal tube is used.
(2) May use a narcotic (fentanyl, 2–5 mcg/kg) just before induction.
(1) Standard maintenance is with fentanyl, 10 to 50 mcg/kg, or an inhalation agent (or both) titrated according to individual patient response.
(2) Antibiotics and immunosuppressants are given at the surgeon’s request.
(3) Position the patient supine and pad pressure points. Avoid stretching the brachial plexus greater than 90 degrees.
(4) Reperfusion syndrome (which occurs during the revascularization phase) is characterized by decreased heart rate, hypotension, conduction defects, and decreased systemic vascular resistance while right ventricular pressures increase. The cause is unknown. Cardiac output can be maintained. An increase in serum potassium can lead to cardiac arrest.
a) Monitoring of hepatic function using laboratory data: Serial liver function tests, prothrombin time, partial thromboplastin time, ammonia levels, lactate, and bile output
b) Possible complications: Bleeding, portal vein thrombosis, hepatic artery thrombosis, biliary tract leaks, primary nonfunction, rejection, infection, pulmonary complications, electrolyte imbalances, hypertension, alkalosis, renal failure, peptic ulceration, and neurologic complications
O Pancreatectomy
Whereas distal pancreatectomy is performed for tumors in the distal half of the pancreas, subtotal pancreatectomy involves resection of the pancreas from the mesenteric vessels distally, leaving the head and uncinate process intact. In about 95% of patients with pancreatic cancer, the cancer is ductal adenocarcinoma, and most of these tumors occur in the head of the pancreas. Insulinoma is the most commonly occurring endocrine tumor of the pancreas.
Pancreatic cancer may appear as a localized mass or as a diffuse enlargement of the gland on computed tomography of the abdomen. Biopsy of the lesion is necessary to confirm the diagnosis. Complete surgical resection is the only effective treatment of ductal pancreatic cancer.
Patients requiring pancreatic surgery can be divided into four groups: (1) those with acute pancreatitis in whom medical treatment has failed in the past, (2) patients with adenocarcinoma of the pancreas, (3) patients with neuroendocrine-active or -inactive islet cell tumors, and (4) patients with the sequelae of chronic pancreatitis (abscess or pseudocyst).
a) History and physical examination
(1) Cardiovascular: Patients with acute pancreatitis may be hypotensive and may require aggressive volume resuscitation with crystalloid and even blood before surgery. Severe electrolyte disturbances may be associated with acute pancreatitis and some hormone-secreting tumors of the pancreas. Hypocalcemia is often present and can cause dysrhythmias and hypotension.
(2) Respiratory: Respiratory compromise such as pleural effusions, atelectasis, and adult respiratory distress syndrome progressing to respiratory failure may occur in up to 50% of patients with acute pancreatitis.
(3) Gastrointestinal: Jaundice and abdominal pain are common symptoms in this group of patients. The presence of ileus or intestinal obstruction should mandate full-stomach precautions and rapid-sequence induction. Electrolyte disturbances are common in acute pancreatitis and may include hypochloremic metabolic alkalosis, decreased calcium and magnesium, and increased glucose. These abnormalities should be corrected preoperatively.
(4) Endocrine: Many patients with acute pancreatitis may have diabetes secondary to loss of pancreatic tissue. Hormone-secreting tumors of the pancreas are occasionally associated with multiple endocrine neoplasia syndromes. Insulinoma is the most common hormone-secreting tumor of the pancreas and can result in hypoglycemia.
(5) Renal: Patients should be evaluated for renal insufficiency.
(6) Hematologic: Hematocrit may be falsely elevated because of hemoconcentration or hemorrhage. Coagulopathy, including disseminated intravascular coagulation, may occur.
(1) Laboratory tests: Complete blood count, prothrombin time, partial thromboplastin time, platelet count, electrolytes, blood urea nitrogen, creatinine, blood sugar, calcium, magnesium, amylase, and urinalysis, as well as other tests as indicated by the history and physical examination
(2) Diagnostic tests: Chest radiography, pulmonary function tests, electrocardiography, and computed tomography of the abdomen, as well as other tests as indicated by the history and physical examination
(3) Medication: Standard premedication with consideration for aspiration prophylaxis
General endotracheal anesthesia is used; consider an epidural technique for postoperative analgesia.
(1) This is standard, with consideration of rapid-sequence intubation as indicated.
(2) Restore intravascular volume before anesthetic induction.
(3) If the patient is hemodynamically unstable, consider etomidate (0.2–0.4 mg/kg) or ketamine (1–3 mg/kg).
(1) Standard maintenance: This involves a narcotic, inhalation agent, or both.
(2) Avoid nitrous oxide to minimize bowel distention.
(3) Combined epidural and general anesthesia: Be prepared to treat hypotension with fluid and vasopressors.
(4) Titrate epidural anesthesia as indicated by patient’s response.
(5) General anesthesia is administered to supplement regional anesthesia and for amnesia. If a patient is not a candidate for epidural, low-dose ketamine infusion is an option. Also, gabapentin 600 to 1200 mg orally once before surgery can decrease post pain.
(6) Position: The patient is supine, with checked and padded pressure points. Avoid stretching the brachial plexus. Limit abduction to 90 degrees.
(7) If patient has insulinoma, the most common endocrine tumor of the pancreas, anticipate potential uncontrolled insulin release.
c) Emergence: The decision to extubate at the end of the operation depends on the patient’s underlying cardiopulmonary status and the extent of the surgical procedure. Patients should be hemodynamically stable, warm, alert, cooperative, and fully reversed from any muscle relaxants before extubation.
Significant third-space and evaporative losses contribute to hypovolemia. Major hemorrhage can occur during dissection of the pancreas from the mesenteric and portal vessels. Total pancreatectomy is associated with diabetes that can be difficult to control. Subtotal resections lead to varying degrees of hyperglycemia. The patient should recover in an intensive care unit or hospital ward accustomed to treating the side effects of epidural opiates.
Tests for postoperative management include electrolytes, calcium, glucose, complete blood count, platelets, and other tests as indicated. Electrolyte disturbances are common in acute pancreatitis and may include hypochloremic metabolic alkalosis, decreased calcium and magnesium, and increased glucose. These abnormalities should be corrected preoperatively.
P Small bowel resection
Small bowel resection is performed for various diseases, including intestinal obstruction, small bowel tumors, abdominal trauma, stricture, adhesions, Meckel’s diverticulum, Crohn’s disease, and infection.
2. Preoperative assessment and patient preparation
a) History and physical examination: Assess fluid and hydration status. The patient may be vomiting or bleeding or may have third spacing, diarrhea, dehydration, or sepsis.
b) Diagnostic laboratory tests should include a complete blood count, electrolyte panel, coagulation panel
a) Epidural (T2–T4 level) with a “light” general anesthetic
b) General anesthesia with an endotracheal tube is necessary for small bowel resections that use a laparoscopic-assisted approach.
a) Induction: Most patients are considered to have full stomachs; therefore, rapid-sequence induction is indicated. Medications used for aspiration prophylaxis should be administered.
(1) Muscle relaxation is required.
(2) Closely monitor hydration status and blood loss; anticipate large fluid shifts.
c) Emergence: Awake extubation is performed after rapid-sequence induction or placement of a nasogastric tube.
Q Splenectomy
Patients presenting for splenectomy can be divided into two groups: trauma patients and patients with myeloproliferative disorders and other varieties of hypersplenism. Anesthetic management is individualized based on the individual patient’s medical condition. Patients who have received chemotherapy must be assessed for potential organ system complications. Laparoscopic-assisted splenectomy best suited for normal and slightly enlarged spleens. The laparoscopic approach is unusually contraindicated in patients with cancer, large hilar lymph nodes, and portal hypertension. The only absolute contraindication to laparoscopic splenectomy is massive splenomegaly (spleen >30 in longitudinal axis).
a) History and physical examination
(1) Cardiovascular: Patients with systemic disease may be chronically ill and have decreased cardiovascular reserve. Patients who have received doxorubicin (Adriamycin) may have a dose-dependent cardiotoxicity that can be worsened by radiation therapy. Manifestations include decreased QRS amplitude, congestive heart failure, pleural effusions, and dysrhythmia.
(2) Respiratory: Patients may have a degree of left lower lobe atelectasis and altered ventilation. If they are treated with bleomycin, pulmonary fibrosis may occur. Methotrexate, busulfan, mitomycin, cytarabine, and other chemotherapeutic agents may cause pulmonary toxicity. A laparoscopic approach may be contraindicated in patients with severe cardiac or respiratory disease.
(3) Neurologic: Patients may have neurologic deficits after taking chemotherapeutic agents. Vinblastine and cisplatin can cause peripheral neuropathies. Any evidence of neurologic dysfunction should be documented.
(4) Hematologic: Patients are likely to have splenomegaly secondary to hematologic disease (Hodgkin’s disease, leukemia). Cytopenias are common.
(5) Hepatic: Some chemotherapeutic agents (methotrexate, 6-mercaptopurine) may be hepatotoxic. Evaluation of liver function tests should be considered in patients considered at risk.
(6) Renal: Some chemotherapeutic drugs (methotrexate, cisplatin) are nephrotoxic. Patients exposed to such agents may have renal insufficiency.
(1) Laboratory tests: Complete blood count, prothrombin time, partial thromboplastin time, bleeding time, platelet count, electrolytes, blood urea nitrogen, creatinine, urinalysis, and other tests are obtained as indicated by the history and physical examination. A type and screen should be obtained due to the potential for major blood loss.
(2) Medication: Standard premedication. Consider aspiration prophylaxis. Administer steroids (25–100 mg hydrocortisone) if the patient has received them as part of a chemotherapeutic or medical treatment.
General endotracheal anesthesia with or without an epidural for postoperative analgesia is used.
(1) This is standard, with consideration of rapid-sequence intubation as indicated.
(2) Restore intravascular volume before anesthetic induction. If the patient is hemodynamically unstable, consider etomidate or ketamine.
(1) Standard regimens are used; if bleomycin has been administered as part of the chemotherapeutic treatment, an oxygen concentration above 30% is indicated to decrease the potential for acute lung injury.
(2) Combined epidural and general anesthesia: See the earlier discussion of pancreatectomy.
(3) Position: The patient is supine, with checked and padded pressure points. Avoid stretching the brachial plexus. Limit abduction to 90 degrees. For the laparoscopic approach, the patient should be on a beanbag in 45-degree lateral decubitus position and full lateral decubitus position.
c) Emergence: The decision to extubate at the end of the operation depends on the patient’s underlying cardiopulmonary status and the extent of the surgical procedure. Patients should be hemodynamically stable, warm, alert, cooperative, and fully reversed from any muscle relaxants before extubation.
R Whipple resection
Whipple resection consists of a pancreatoduodenectomy, pancreatojejunostomy, hepaticojejunostomy, and gastrojejunostomy. On entering the peritoneal cavity, the surgeon determines the resectability of the pancreatic lesion. Contraindications to resection include involvement of mesenteric vessels, infiltration by tumor into the root of the mesentery, extension into the porta hepatis with involvement of the hepatic artery, and liver metastasis. If the tumor is deemed resectable, the head of the pancreas is further mobilized. The common duct is transected above the cystic duct entry, and the gallbladder is removed. When the superior mesenteric vein is freed from the pancreas, the latter is transected with care taken not to injure the splenic vein. The jejunum is transected beyond the ligament of Treitz, and the specimen is removed by severing the vascular connections with the mesenteric vessels. Reconstitution is achieved by anastomosing the distal pancreatic stump, bile duct, and stomach into the jejunum. Drains are placed adjacent to the pancreatic anastomosis. Some surgeons stent the anastomosis until it has healed.
See the earlier discussion of pancreatectomy.
General endotracheal anesthesia with an epidural for postoperative analgesia is used. See the earlier discussion of pancreatectomy.
