Cecilia K. Wieslander, MD
Danielle D. Marshall, MD
PREOPERATIVE COMPLICATIONS
One of the main purposes of the preoperative history and physical exam is to identify any preoperative medical comorbidity that may lead to an increased perioperative morbidity or mortality. If comorbidities are identified, the surgeon should obtain medical consultation to ensure that the patient’s medical conditions are optimized and stable enough to proceed with surgery at an acceptable risk.
CARDIOVASCULAR DISEASE
Clinical Findings
Most gynecologic surgeries fall in the low (<1%) or intermediate (1–5%) risk of cardiac death or nonfatal myocardial infarction (Table 45–1). It is crucial to obtain a careful preoperative history to discover cardiac and/or comorbid diseases that would place the patient in a high surgical risk category. If the patient is found to have active cardiac conditions, such as unstable coronary syndrome, decompensated heart failure, significant arrhythmias, or severe valvular disease, the surgery should be delayed or cancelled (unless emergent), and the patient should be evaluated and treated (Table 45–2). One should also determine if the patient has a prior history of a pacemaker, implantable cardioverter-defibrillator, orthostatic intolerance, or other clinical risk factors that are associated with increased perioperative cardiovascular risk (Table 45–2). If the patient has a history of cardiac disease, any recent change in symptoms must be elicited. In addition, one should record current medications including doses and any use of alcohol, tobacco, and over-the-counter and illicit drugs. The history should also include the patient’s functional capacity (Table 45–3). Assessing a person’s capacity to perform common daily tasks correlates well with maximum oxygen uptake by treadmill testing.
Table 45–1. Cardiac risk (cardiac death and nonfatal myocardial infarction) for noncardiac procedures.
Table 45–2. Clinical risk factors for increased perioperative cardiovascular complications (myocardial infarction, heart failure, death).
Table 45–3. Estimated energy requirements for various activities.
The American College of Cardiology/American Heart Association 2007 Guidelines on Perioperative Cardiovascular Evaluation and Care for Noncardiac Surgery recommend a stepwise approach to perioperative cardiac assessment.
Step 1: Does the patient need emergency noncardiac surgery? If yes, one should proceed with surgery and perioperative surveillance and postoperative stratification and risk factor management. If no, one should proceed with step 2.
Step 2: Does the patient have active cardiac conditions (see Table 45–2)? If yes, the surgery should be postponed and the conditions evaluated and treated. If no, proceed with step 3.
Step 3: Is the planned procedure a low-risk surgery (see Table 45–1)? If yes, proceed with the planned surgery. If no, proceed with step 4.
Step 4: Does the patient have good functional capacity (≥4 metabolic equivalents [MET]; see Table 45–3) without symptoms? If yes, proceed with planned surgery. If no, proceed with step 5.
Step 5: If the patient has poor functional capacity, is symptomatic, or has unknown functional capacity, then the presence of active clinical risk factors determines the need for further evaluation. Clinical risk factors include a history of heart disease, compensated or prior heart failure, cerebrovascular disease, diabetes mellitus, and renal insufficiency.
• ≥3 clinical risk factors + high-risk surgery: testing should be considered if it will change management.
• ≥3 clinical risk factors + intermediate surgery: proceed with planned surgery with heart rate control with beta-blocker or consider noninvasive testing if it will change management.
• 1 or 2 clinical risk factors + high-risk surgery: proceed with planned surgery with heart rate control with beta-blocker or consider noninvasive testing if it will change management.
• 1 or 2 clinical risk factors + intermediate surgery: proceed with planned surgery with heart rate control with beta-blocker or consider noninvasive testing if it will change management.
• No clinical risk factors: proceed with planned surgery.
Treatment
A. Coronary Artery Disease
In patients with known or previous occult coronary artery disease, one has to determine the amount of myocardium in jeopardy, the ischemic threshold, the ventricular function, and whether the patient’s condition is optimized. Selective noninvasive testing can be used to determine the patient risk of ischemia during surgery.
B. Hypertension
Induction of anesthesia causes an increase in blood pressure and heart rate due to sympathetic activation. These changes are more pronounced in patients with untreated hypertension than in patients with well-controlled hypertension. Elective surgery should be delayed for stage 3 hypertension (systolic blood pressure ≥180 mm Hg and diastolic blood pressure ≥100 mm Hg). If emergent surgery is needed, rapid-acting intravenous agents should be used to control the blood pressure perioperatively.
Patients should continue taking their antihypertensive medications with a sip of water the morning of surgery, and medications should be resumed postoperatively. Some physicians recommend withholding angiotensin-converting enzyme inhibitors and angiotensin receptor antagonists the morning of surgery. These medications can be restarted postoperatively after the patient is euvolemic to decrease the risk of perioperative renal dysfunction.
Postoperatively, reversible causes of hypertension, such as pain, anxiety, hypervolemia, hypercarbia, hypoxia, and bladder distension should be treated. Patients on chronic antihypertensive medications should restart their usual medications as needed. Patients with sustained systolic blood pressure greater than 180 mm Hg or diastolic blood pressure greater than 110 mm Hg should be treated once reversible causes have been addressed.
C. Valvular Heart Disease
In patients with symptomatic aortic stenosis, elective non-cardiac surgery should be postponed or cancelled because the mortality risk is approximately 10%. Such patients require aortic valve replacement before elective but necessary noncardiac surgery. If the aortic stenosis is severe but asymptomatic, the surgery should be postponed or cancelled if the valve has not been evaluated within the year.
Significant mitral stenosis increases the risk of heart failure. When the stenosis is severe, the patient may benefit from balloon mitral valvuloplasty or open surgical repair before high-risk surgery. However, in general, preoperative surgical correction is not indicated, unless the valvular condition should be corrected to prolong survival.
Patients with atrial fibrillation who are at risk for thromboembolism should be given preoperative and postoperative intravenous heparin or low-molecular-weight heparin to cover periods of subtherapeutic anticoagulation.
Patients with mechanical prosthetic valves need careful anticoagulation management when they undergo surgery. Perioperative heparin is recommended for patients in whom the risk of bleeding with oral anticoagulation is high and the risk of thromboembolism without anticoagulation is also high. These patients include patients with mechanical heart valve in the mitral position, Bjork-Shiley valve, recent (<1 year) thrombosis or embolus, or 3 or more of the following risk factors: atrial fibrillation, previous embolus at any time, hypercoagulable condition, mechanical prosthesis, and left ventricular ejection fraction less than 30%.
Recommendations regarding endocarditis prophylaxis in patients with mechanical heart valves have recently been changed. The American Heart Association no longer recommends endocarditis prophylaxis in patients undergoing genitourinary or gastrointestinal surgery, including gynecologic surgery, or vaginal delivery or caesarean section. The only exception is in a patient with an infection that could cause bacteremia, such as chorioamnionitis or pyelonephritis. In these cases, the underlying infection should be treated in the usual fashion, and the treatment should include a regimen effective for infective endocarditis prophylaxis (Table 45–4). In addition to prosthetic heart valves, the American Heart Association only recommends endocarditis prophylaxis for previous infective endocarditis and congenital heart disease (Table 45–5).
Table 45–4. Antibiotic prophylaxis for infective endocarditis.
Table 45–5. Cardiac conditions for which prophylaxis for obstetric-gynecologic procedures associated with infection or dental procedures is reasonable.
Fleischer LA, Beckman JA, Brown KA, et al. The ACC/AHA 2007 guidelines on perioperative cardiovascular evaluation and care for noncardiac surgery: executive summary. J Am Coll Cardiol2007;50:1707–1732. PMID: 17950159.
Wilson W, Taubert KA, Gewitz M, et al. Prevention of infective endocarditis: guidelines from the American Heart Association: a guideline from the American Heart Association Rheumatic Fever, Endocarditis and Kawasaki Disease Committee, Council on Cardiovascular Disease in the Young, and the Council on Clinical Cardiology, Council on Cardiovascular Surgery and Anesthesia, and the Quality of Care and Outcomes Research Interdisciplinary Working Group. Circulation 2007;116:1736–1754. PMID: 17446442.
VENOUS THROMBOEMBOLISM
In patients with a prior history of venous thromboembolism (VTE; pulmonary embolism or deep vein thrombosis [DVT]), it is important to weigh the risk of a thromboembolic event during interruption of anticoagulation against the risk of bleeding when antithrombotic therapy is administered in close proximity to surgery. Patients can be divided into risk strata according to their suggested risk for perioperative thromboembolism:
High risk:
• Recent (within 3 months) VTE
• Severe thrombophilia (eg, deficiency of protein C, protein S or antithrombin, antiphospholipid antibodies, or multiple abnormalities)
Moderate risk:
• VTE within the past 3–12 months
• Nonsevere thrombophilic conditions (eg, heterozygous factor V Leiden mutation, heterozygous factor II mutation)
• Recurrent VTE
• Active cancer (treated within 6 months or palliative)
Low risk:
• Single VTE occurred >12 months ago and no other risk factors
For patients undergoing a major surgical procedure, vitamin K antagonists (warfarin) should be stopped 5 days and antiplatelet drugs (aspirin, clopidogrel) 7–10 days before the procedure. Nonsteroidal anti-inflammatory drugs (NSAIDs) cause reversible inhibition of platelet-mediated cyclooxygenase activity. NSAIDs with a short half-life (eg, ibuprofen, indomethacin) should be stopped on the day before surgery, whereas NSAIDs with an intermediate half-life (eg, naproxen, celecoxib) should be stopped 2–3 days before surgery. NSAIDs with a long half-life (>20 hours) should be stopped 10 days before surgery. If the international normalized ratio (INR) is still elevated (ie, ≥1.5) 1–2 days before surgery, low-dose (ie, 1–2 mg) oral vitamin K can be administered to normalize the INR. Vitamin K antagonists should be restarted approximately 12–24 hours after surgery and when there is adequate hemostasis. Similarly, anti-platelet drugs should be resumed approximately 24 hours (or the next morning) after surgery when there is adequate hemostasis.
Patients at high or moderate risk (see risk strata) for perioperative thromboembolism need bridging anticoagulation with therapeutic-dose subcutaneous low-molecular-weight heparin (LMWH) or intravenous unfractionated heparin (UFH). Patients at low risk for perioperative thromboembolism can use low-dose subcutaneous LMWH or no bridging. Bridging with LMWH can be easily administrated outside the hospital and does not require laboratory monitoring. A common regimen is enoxaparin 1 mg/kg twice a day. The last dose of therapeutic LMWH should be given the morning prior to the day of surgery, thus holding the evening dose. Therapeutic LMWH can be restarted in 24 hours for patients undergoing minor surgical or other invasive procedures but should be held for 48–72 hours in patients undergoing major surgery. Bridging using therapeutic-dose intravenous UFH is performed by achieving a target activated partial thromboplastin time (aPTT) of 1.5–2.0 times the control aPTT value. The infusion is stopped approximately 4 hours before the surgery and is restarted during the initial 24 hours postoperatively. Bridging with LMWH is preferred to intravenous UFH in an outpatient setting.
In patients who are receiving vitamin K antagonists and require an urgent surgical procedure, the anticoagulant effect can be reversed with low-dose (2.5–5 mg) intravenous or oral vitamin K. If an immediate reversal effect is needed, the patient can be given fresh-frozen plasma or other prothrombin concentrate in addition to vitamin K. Because there is no pharmacologic agent that can reverse the antithrombotic effect of aspirin, clopidogrel, or ticlopidine, transfusion of platelets or the administration of other prohemostatic agents can be given to patients who are undergoing surgery and have excessive or life-threatening bleeding.
Douketis JD, Berger PB, Dunn AS, et al. The perioperative management of antithrombotic therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest2008;133(6 Suppl):299S–339S. PMID: 18574269.
PULMONARY DISEASE
Complications
Postoperative pulmonary complications, such as atelectasis, pneumonia, respiratory failure, and exacerbation of underlying chronic lung disease, occur at similar rates to cardiac complications. In a study of 2964 patients undergoing elective noncardiac surgery, postoperative pulmonary and cardiac complications occurred in 2.0% and 2.2%, respectively.
All patients undergoing noncardiothoracic surgery should be evaluated for the presence of significant risk factors for postoperative pulmonary complications in order to receive pre- and postoperative interventions to reduce pulmonary risk. These risk factors include (1) chronic obstructive pulmonary disease, (2) age older than 60 years, (3) American Society of Anesthesiologists (ASA) class II or greater, (4) functionally dependent, (5) and congestive heart failure. Chronic obstructive pulmonary disease is the most commonly identified risk factor for postoperative pulmonary complications, with an odds ratio of 1.79. Advancing age is an important predictor of postoperative pulmonary complications, even after adjusting for comorbid conditions. The risk for pulmonary complications increases 2-fold for patients age 60–69 and 3-fold for patients age 70–79. The ASA classification (Table 45–6) has been proven to predict both postoperative pulmonary and cardiac complications. An ASA class of II or higher has a 4.9 times higher risk of pulmonary complications compared to ASA class I. Similarly, an ASA class of II or greater has a 2.3 times higher risk of pulmonary complications than ASA class of I or II combined. Functional dependence also increases the risk of postoperative pulmonary complications. Total dependence (inability to perform any activities of daily living) increases the risk by 2.5 times, whereas partial dependence (need for equipment or devices and assistance from another person for some activities of daily living) increases the risk by 1.7 times. Finally, congestive heart failure increases the risk of postoperative pulmonary complications by almost 3 times. Cigarette smoking has only a modest increased risk of pulmonary complications, with an odds ratio of 1.26. Contrary to previous beliefs, obesity and mild to moderate asthma are not significant risk factors for postoperative pulmonary complications.
Table 45–6. American Association of Anesthesiologists (ASA) classification.
Procedure-related risk factors are another important consideration when trying to reduce postoperative pulmonary complications. Certain procedures carry a higher risk of complications. These procedures include aortic aneurysm repair, thoracic surgery, abdominal surgery (especially upper abdominal surgery), neurosurgery, prolonged surgery, head and neck surgery, emergency surgery, and vascular surgery. The duration of surgery also affects postoperative pulmonary complications. A prolonged surgery lasting over 3–4 hours doubles the rate of postoperative pulmonary complications. Finally, general anesthesia and emergency surgery increase the risk of postoperative pulmonary complications by an odds ratio of 1.83 and 2.21, respectively.
Laboratory testing to estimate surgical risk has not been shown to be better than a careful history and physical exam. Therefore, the American College of Physicians does not recommend preoperative spirometry or chest radiography to predict risk for postoperative pulmonary complications. Spirometry is recommended for thoracic surgery only, and studies of preoperative chest radiographs have shown that 10–23% of chest radiographs are abnormal but only 1.3–3% were clinically significant. Interestingly, a low serum albumin of <3.5 mg/dL is a powerful marker of increased risk for postoperative pulmonary complications and should be measured in all patients who are suspected of having hypoalbuminemia. Measurements should be considered in patients with 1 or more risk factors for pulmonary complications.
Treatment
All patients who are found to be at higher risk for postoperative pulmonary complications after perioperative evaluation should receive treatment to reduce postoperative complications. These treatments include (1) deep breathing exercises or incentive spirometry and (2) selective use of a nasogastric tube in patients for postoperative nausea and vomiting, inability to tolerate oral intake, or symptomatic abdominal distension.
Smetana GW, Lawrence VA, Cornell JE. Preoperative pulmonary risk stratification for noncardiothoracic surgery: systematic review for the American College of Physicians. Ann Intern Med 2006;144:581–595. PMID: 16618956.
ENDOCRINE DISEASE
Endocrine disorders are common in patients presenting for elective surgery. This section will discuss the perioperative management of diabetes, hyper- and hypothyroidism, and corticosteroid-induced adrenal insufficiency.
1. Diabetes Mellitus
Clinical Findings
Diabetes is the most common endocrine disorder affecting almost 20 million Americans. Fifty percent of these patients are estimated to require surgery during their lifetime. All patients with diabetes should have a careful preoperative assessment. The physician should ask about existing diabetic complications, such as neuropathies (peripheral sensory, bladder dysfunction, gastroparesis, and hypoglycemic unawareness), retinopathy, nephropathy, hyperlipidemia, and hypertension. Preoperative glucose control should be evaluated, since elevated blood sugar >150 mg/dL leads to macrophage dysfunction. This increases the risk of infection and delayed wound healing. Glycosylated hemoglobin (HbA1c) value is an indicator of glycemic level over 120 days but is strongly related to the level over the last 2–3 months. A normal value is up to 6%, and the goal of the American Diabetes Association is an HbA1c level less than 7% (considered adequate control). HbA1c values over 8% correspond to average blood glucose levels greater than 180 mg/dL and are an indication of poor glycemic control. Because diabetes is the leading cause of renal failure, it is important to measure the renal function preoperatively. Impaired renal function increases the risk of perioperative hypoglycemia because it prolongs the half-life of insulin and sulfonylureas. The major goal of perioperative management in patients with diabetes is to minimize hyperglycemia and avoid hypoglycemia, hypovolemia, and hypo- or hyperkalemia. Surgery and anesthesia invoke a stress response that leads to a hypersecretion of counterregulatory hormones culminating in hyperglycemia. This may lead to diabetic ketoacidosis (DKA) in patients with type 1 diabetes and hyperosmolar hyperglycemia nonketosis (HHNK) in patients with type 2 diabetes. There are no current guidelines on perioperative glycemic control, but a reasonable approach is to maintain blood glucose levels at less than 200 mg/dL intraoperatively and less than 150 mg/dL postoperatively, but avoid levels less than 80 mg/dL.
Treatment
Perioperative management of antihyperglycemic medications can be challenging, especially if the patient is required to be NPO (nothing by mouth) perioperatively. Thiazolidinedione (rosiglitazone, pioglitazone, and troglitazone) can be held the morning of surgery and sulfonylureas (glipizide and glyburide) must be held preoperatively. The biguanide metformin, which has been associated with the development of lactic acidosis, should be withheld 24 hours preoperatively and restarted 48–72 hours postoperatively once normal renal function has been documented. Thiazolidinedione and sulfonylureas can be restarted once enteral intake is permitted.
Patients who routinely use insulin should preferably be scheduled as the first case of the day to minimize hyper-or hypoglycemia. Patients with type 1 diabetes need basal insulin at all times to avoid DKA. The night before the procedure, the patient should take usual oral intake and continue the usual dose of evening glargine/NPH or a mixture. Patients using insulin pumps should continue the usual overnight basal rate. During the morning of the procedure, short-acting hypoglycemics should not be given unless the blood sugar is greater than 200 mg/dL and greater than 3 hours preoperatively. If the patient takes glargine insulin (long-acting), the usual dose of glargine can be given or the patient can be placed on an insulin drip. Patients using an insulin pump should continue the usual basal rate and infuse D5 throughout the operation. If the patient takes NPH (intermediate-acting) or other insulin mixture, the following steps should be taken. No short-acting insulin should be given within 3–4 hours of the procedure (ie, no mixture preoperatively). Half the usual dose of intermediate-acting insulin, with D5 at a controlled rate, should be given throughout the procedure. If performing an operation without continuous D5, insulin should not be given preoperatively. During emergency surgery, bolus of short-acting insulin should not be given preoperatively. Instead, frequent (every 30–60 minutes) monitoring of blood sugars should be performed throughout the operation. An insulin drip should be started for blood sugars greater than 200 mg/dL.
2. Hyperthyroidism
Clinical Findings
Untreated hyperthyroidism causes an increase in blood pressure, heart rate, and circulating blood volume, which leads to an increased cardiac output of 50–300%. These changes may limit the patient’s ability to respond to the stress of surgery and can lead to thyroid storm and cardiovascular collapse. Therefore, thyroid function tests should be evaluated in all patients with hyperthyroidism preoperatively.
Treatment
Patients with uncontrolled hyperthyroidisms who present for elective surgery should have their surgery postponed until they have been stabilized medically. If a patient needs urgent or emergent surgery, the anesthesiologist should have drugs available that block the systemic effects of excess thyroid hormones, such as beta-blockers, antithyroid medications (propylthiouracil and methimazole), and iodine. The patient should take their antithyroid medications on the morning of surgery and resume the medications postoperatively when they tolerate enteral intake.
Complications
The most serious perioperative complication is thyroid storm, which usually arises from undiagnosed or under-treated hyperthyroidism. It can occur at any time in the perioperative period but usually occur intraoperatively or in the first 48 hours. Symptoms of thyroid storm are nonspecific and include fever (up to 41.1°C), tachycardia, and delirium. The mortality rate is 10–75%, and the patient must be treated in a critical care environment. Treatment includes thionamides, beta-blockers, antipyretics, and external cooling measures.
3. Hypothyroidism
Clinical Findings
Hypothyroidism is a common endocrine disorder that affects 1% of all patients. Patients with well-controlled hypothyroidism and patients with mild to moderately controlled hypothyroidism can usually undergo elective surgery without an increase in their perioperative risk. The physician should monitor closely for symptoms of worsening hypothyroidisms including delirium, prolonged ileus, infections without fever, and myxedema coma. Due to the long half-life of levothyroxine (1 week), it is not necessary for the patient to take their dose the morning of surgery. Levothyroxine can be restarted postoperatively once the patient tolerates enteral intake.
Treatment
Patients with severe hypothyroidism (myxedema coma) should be stabilized medically before any elective surgery. Myxedema coma is rare and usually presents postoperatively. It has a reported mortality rate of 80% and is precipitated by insults such as infection, cold exposure, and medications (sedatives and analgesics). Myxedema coma is characterized by severely depressed mental status (sometimes coma or seizures), hypothermia, bradycardia, hyponatremia, heart failure, and hypopnea. Myxedema coma is a medical emergency requiring intensive care admission and urgent administration of intravenous levothyroxine. Dehydration is often present, and aggressive fluid resuscitation with dextrose and normal saline should be performed. Intravenous glucocorticoids should be given because concomitant adrenal insufficiency is often present. Resolution of symptoms should be seen within 24 hours.
4. Adrenal Insufficiency
Adrenal insufficiency (AI) limits a patient’s ability to respond to stress during surgery.
Pathogenesis
Primary AI is caused by autoimmune adrenalitis, infection, adrenalectomy, and sepsis, whereas secondary AI is due to pituitary depression, damage, and tumors. Tertiary AI is caused by exogenous glucocorticoid administration, which suppresses hypothalamic corticotropin-releasing hormone and pituitary adrenocorticotropic hormone (ACTH). These patients may need perioperative steroid supplementation (stress dose steroids).
Treatment
There is a wide variability in individual response to a particular dose and length of treatment. However, in general, patients who have received the equivalent of 20 mg/d of prednisone for greater than 5 days may be at risk for AI. If the patient has been on therapy for 1 month or longer, they may have AI for up to 6–12 months after stopping therapy. Patients who have been on an equivalent dose of prednisone 5 mg (or less) for any period of time will usually not have AI and will not need to receive stress dose steroids. The treatment of patients taking more than 5 mg/d of prednisone or equivalent is controversial. Some experts recommend performing a short ACTH stimulation test preoperatively in patients receiving steroid equivalents of 20 mg/d. Only patients who do not respond appropriately would receive stress dose steroids perioperatively. Others perform the ACTH stimulation test for patients receiving 6–19 mg/d of prednisone while giving patients taking 20 mg/d or higher stress dose steroids. Finally, some authors recommend giving all patients taking more than 5 mg/d of prednisone equivalent-dose stress dose steroids. In our practice, we treat all patients taking more than 5 mg/d of prednisone with stress dose steroids perioperatively. Patients taking 5 mg/d or less of prednisone should continue their usual maintenance dose orally or intravenously as the clinical situation mandates.
Coursin DB, Wood KE. Corticosteroid supplementation for adrenal insufficiency. JAMA 2002;287:236–240. PMID: 11779267.
Kohl BA, Schwartz S. Surgery in the patient with endocrine dysfunction. Med Clin N Am 2009;93:1031–1047. PMID: 19665618.
RENAL DISEASE
Clinical Findings
Preoperative laboratory studies should include a measure of the glomerular filtration rate (GFR) to ensure that the correct dosage of medications excreted by the kidney is given. A complete blood count and a type and screen should be performed because many patients with chronic renal disease have anemia and some patients may require a preoperative blood transfusion. Electrolytes should be checked because electrolyte disturbances are common. Up to 50% of patients have hyperkalemia, and some studies suggest that acute intervention should be reserved for potassium levels greater than 6.5 mmol/L.
Complications
Patients with chronic renal disease have a 2- to 5-fold higher risk of postoperative death and cardiovascular events than those with normal kidney function. Patients receiving dialysis are at the highest risk of such events.
During the preoperative assessment, the physician should establish the type and severity of kidney disease, any comorbid conditions, any complications related to the level of kidney function, risk for loss of kidney function, and risk for cardiovascular disease. Modifiable risk factors should be optimized prior to surgery. A mean arterial blood pressure of 110 mm Hg is associated with increased rates of cardiovascular and renal complications. Therefore, the preoperative blood pressure goal should be 130/80 mm Hg. To minimize the risk of volume overload, electrolyte imbalances, and uremic bleeding, patients requiring dialysis should receive it within 24 hour of surgery. Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin II antagonists (ARAs) are associated with intraoperative hypotension, especially with induction of general anesthesia. It is recommended to discontinue ACEIs and ARAs for at least 10 hours before general anesthesia.
Treatment
If a patient needs contrast media intraoperatively or during a radiologic study, a nonionic contrast agent is recommended to reduce the risk of contrast-induced nephropathy. In addition, the patients should be well hydrated, other nephrotoxic drugs and hypotension should be avoided, and medications such as N-acetylcysteine (Mucomyst 600 mg orally twice daily on the day before and/or on the day of the procedure) can be given. Laparoscopy reduces renal blood flow and can cause hypotension (which can further aggravate reduced renal blood flow). To mitigate these changes, abdominal insufflation pressures should not exceed 15 mm Hg, and adequate fluid replacement is recommended.
Jones DR, Lee HT. Surgery in the patient with renal dysfunction. Med Clin North Am 2009;93:1083–1093. PMID: 18299098.
Mathew A, Devereaux PJ, O’Hare A, et al. Chronic kidney disease and postoperative mortality: a systematic review and meta-analysis. Kidney Int 2008;73:1069–1081. PMID: 19665621.
HEPATIC DISEASE
Clinical Findings
Management of the surgical patient with liver disease should begin with a careful history and physical exam. This also serves as a screening test for patients with asymptomatic disease. One should ask about a history of prior surgeries, jaundice or blood transfusions, use of alcohol and other recreational drugs, sexual history, and a review of systems. The review of systems should include pruritus, easy fatigability, excessive bleeding after minor trauma, abdominal distension, and weight gain. The physical exam should include signs of liver disease, such as icterus, pallor, ascites, hepatomegaly, splenomegaly, palmar erythema, and spider nevi. If there is any suspicion of liver disease, blood testing for hepatic function should be performed including coagulation studies, electrolytes, and liver enzymes. However, routine preoperative testing of liver function is not recommended due to its low yield of abnormal results (<1%).
Complications
Older studies have reported high mortality rates in patients with acute hepatitis. It is therefore recommended to postpone elective surgery in these patients until the liver function tests have normalized. Surgery is generally considered safe in patients with chronic hepatitis. In general, patients with fatty liver tolerate surgery well, while patients with alcoholic hepatitis and cirrhosis have increased postoperative morbidity and mortality. Patients with a history of alcohol abuse have an increased risk of postoperative complications, such as poor wound healing, infections, bleeding, and delirium. Patients should refrain from using alcohol to improve liver function and should be monitored closely for signs of alcohol withdrawal.
Patients with cirrhosis have a high postoperative mortality of 10–80%. These patients may have nutritional disorders, ascites, abnormal coagulation profile, renal dysfunction, and encephalopathy. Five factors that significantly affect mortality in patients with cirrhosis include ascites, albumin, bilirubin, encephalopathy, and nutritional status. Cirrhotic patients benefit from aggressive preoperative treatment of coagulopathy, ascites, and encephalopathy. Coagulopathy can be managed preoperatively with vitamin K (10 mg subcutaneous); however, vitamin K does not correct the prothrombin time if there is decreased hepatic synthesis. In these cases, fresh-frozen plasma (FFP) infusion usually brings the prothrombin time to normal limits. If vitamin K and FFP fail to reduce the prothrombin time to within 3 seconds of normal, cryoprecipitate should be given. Cirrhotic patients are at high risk of developing encephalopathy postoperatively. Constipation, infection, upper gastrointestinal bleeding, uremia, alkalosis, and overuse of sedatives are known precipitating factors of encephalopathy. Ascites can cause respiratory compromise and wound dehiscence. It should be treated aggressively preoperatively with diuretics and paracentesis. Increasing evidence suggests that laparoscopic procedures have decreased operative morbidity and mortality compared with open procedures in patients with cirrhosis.
Rizvon MK, Chou CL. Surgery in the patient with liver disease. Med Clin North Am 2003;87:211–227. PMID: 12575891.
RHEUMATOLOGIC DISEASE
Complications
Two common challenges in the perioperative management of patients with rheumatologic disease are surgical positioning and perioperative management of antirheumatic medications. Patients with rheumatologic disease often have restricted joint mobility and pain. To decrease the risk of postoperative pain exacerbation and intraoperative injury to joints, it is important to preoperatively access the mobility of the joint. In addition, it is helpful to position these patients awake (ie, in lithotomy position) to ensure that the joints are not hyperflexed or hyperextended.
Treatment
When deciding on whether or not to stop an antirheumatic medication, one must weigh the risk of impaired wound healing and postoperative complications with maintaining disease control. Methotrexate has been extensively studied and should be continued in otherwise healthy patients. Compared with patients who discontinued the drug, patients who continued methotrexate had fewer infections and less flares. There are only a limited number of studies on leflunomide, and the results are conflicting. However, due to the very long half-life of leflunomide, its discontinuation would be necessary for a long time and is probably not necessary. Data on hydroxychloroquine do not show an increased risk of infection, and the drug has a long half-life. Clinical data are lacking on the perioperative use of sulfasalazine. The drug has a short half-life and is eliminated primarily via the kidneys. Some authors suggest withholding sulfasalazine at least the day of surgery. Three studies on azathioprine did not show the drug to be associated with any postoperative complications, and it is considered safe. Although preliminary data on tumor necrosis factor (TNF)–blocking agents show that the risk of infections may be lower than initially expected, it is still recommended to discontinue the drugs before surgery for several weeks. TNF-blocking agent should not be restarted until wound healing is complete. There are no data available on the drugs anakinra, rituximab, or abatacept. NSAIDs and aspirin should be discontinued as previously described in this chapter, whereas glucocorticoids should not be discontinued preoperatively. Patient with a suspected suppression of the hypothalamic–pituitary–adrenal axis should receive stress dose steroid supplementation, as previously described.
Pieringer H, Stuby U, Biesenback G. Patients with rheumatoid arthritis undergoing surgery: how should we deal with anti-rheumatic treatment? Semin Arthritis Rheum 2007;36:278–286. PMID: 17204310.
INTRAOPERATIVE COMPLICATIONS
Intraoperative complications can occur even in the most experienced surgeon’s hands. Several factors, such as a surgeon’s experience, technique, and knowledge of the pelvic anatomy, may prevent some of these complications. However, a surgeon must always be prepared to recognize and treat injuries when they occur in an organized and timely fashion. The complications listed in the following sections comprise some of the most common and serious complications encountered in gynecologic surgery.
URINARY TRACT INJURIES
1. Bladder Injury
Bladder injuries most commonly occur while dissecting down the bladder during abdominal or laparoscopic hysterectomy. The bladder may also be injured when attempting to enter the anterior cul-de-sac during vaginal hysterectomy. Bladder laceration can be confirmed by filling the bladder with either sterile milk or methylene blue retrograde through a urethral catheter. The bladder defect is repaired with 2 layers of absorbable suture. The Foley catheter is left in place for several days (5–7 days if injury is at the dome and 7–10 days if injury is at the bladder base) to prevent bladder distention and to allow the repair to heal. Another procedure that may result in bladder injury is retropubic suburethral slings used to treat stress urinary incontinence. The risk is approximately 5%. Therefore, this procedure includes routine cystoscopy to detect these injuries. If a cystotomy is present, the surgeon must replace the trocar and then continue Foley catheter drainage for 2–3 days. Very small injuries to the bladder such as a veress needle injury generally does not require repair and may be treated conservatively with Foley catheter drainage.
2. Ureteral Injury
Clinical Findings
Ureteral injuries are rare but recognized complications in gynecologic surgery. The incidence associated with hysterectomies ranges from 0.03–1.5%. Many of these intraoperative injuries go unrecognized and cause significant morbidity, including pyelonephritis, urine peritonitis, ureterovaginal fistula, and loss of a functioning kidney. Rates of injury are increased with operations for pelvic organ prolapse and in women with adhesions from endometriosis or prior surgery, distorted pelvic anatomy from malignancy, and enlarged uteri.
Common sites of ureteral injuries are at the level of the infundibulopelvic ligament, as the ureter courses under the uterine artery, at the distal uterosacral ligaments, and at the lateral apex of the vagina before its insertion into the bladder. Mechanisms for ureteral damage include transecting, ligating, kinking, burning, devascularizing, or crushing the ureters. Some of these injuries can be detected during surgery; however, the majority of injuries are unsuspected and diagnosed postoperatively. Early recognition of an injury is crucial to preserve the function of that kidney, and repair is most likely to be successful if done during the initial surgery.
Intraoperative cystoscopy with intravenous indigo carmine offers confirmation of bilateral ureteral patency. If efflux of blue dye is sluggish or absent from a ureteral orifice, then a ureteral injury should be suspected. If injury is confirmed, a urology consultation is recommended. If an abdominal procedure is being performed and a cystoscope is unavailable, another method of evaluating the ureteral function is through a purposeful cystotomy using an endoscope. In that case, a purse-string suture is placed at the dome of the bladder, and a small purposeful cystotomy is made within it. The 0- or 30-degree endoscope is then placed through the cystotomy to evaluate the bladder and ureteral orifices. Once the endoscope is removed, the purse-string suture is tied and a second imbricating layer is placed. The bladder should be drained postoperatively for 5–7 days using a Foley catheter. If cystoscopy is not diagnostic or there is strong suspicion of an injury, then transurethral stenting may be required and the appropriate consultation service should be called intraoperatively.
Studies on universal cystoscopy during routine hysterectomies have not been shown to be cost effective given the low rates of ureteral injury. However, if the patient is at higher risk or there is suspicion, cystoscopy should be performed.
If a patient develops flank pain in the postoperative period, a ureteral injury should be suspected. Urinary tract injury can be detected by an intravenous pyelogram (IVP). A renal ultrasound may reveal hydronephrosis or hydroureter. If a fluid collection is noted in the abdomen, it may be a urinoma from a transected ureter. Clear fluid draining from the surgical wound or from the vagina may be from a fistula. If this fluid is sent for creatinine levels, fluid from a urine leak would demonstrate a much higher creatinine concentration than the patient’s serum creatinine levels.
Ibeanu OA, Chesson RR, Echols KT, et al. Urinary tract injury during hysterectomy based on universal cystoscopy. Obstet Gynecol 2009;113:6–10. PMID: 19104353.
Visco AG, Taber KH, Weidner AC, et al. Cost-effectiveness of universal cystoscopy to identify ureteral injury at hysterectomy. Obstet Gynecol 2001;97(5 Pt 1):685–692. PMID: 11339916.
GASTROINTESTINAL TRACT INJURY
Bowel is susceptible to injury during all types of gynecologic, abdominal, laparoscopic, and vaginal surgeries. Patients at highest risk include those with adhesions from previous surgery, endometriosis, tubo-ovarian abscess, or advanced malignancy.
Small Bowel
Patients with adhesions from previous surgery are particularly at risk, especially upon entry into the peritoneal cavity. Small bowel can be injured from electrocautery or via enterotomy. Small defects of the serosal or muscularis may be repaired using interrupted 3-0 silk or synthetic absorbable sutures in 1 or 2 layers. Suture repair lines should be perpendicular to the long axis of the bowel to prevent narrowing of the bowel lumen. Larger injuries and thermal injuries may require segmental resection with reanastomosis or with use of stapling devices.
Large Bowel
Large bowel injury is repaired in a similar fashion as the small bowel. Suture repair and resection with reanastomosis are techniques used in repair. However, if bowel reanastomosis is not possible due to extensive damage or pathology, a diverting colostomy may be needed. Injury to bowel results in spillage of bowel contents into the peritoneal cavity, which causes peritonitis. If unrecognized, the patient usually develops fever, abdominal distention, and pain from peritonitis in the immediate postoperative period. An unrecognized thermal bowel injury from electrocautery may have a delayed onset of symptoms. Any unrecognized bowel injury could potentially be lethal.
Stany MP, Farley JH. Complications of gynecologic surgery. Surg Clin North Am 2008;88:343–359. PMID: 18381117.
VASCULAR INJURY
Major Vessel Injury
Injury to a major blood vessel, such as the iliac vessels, aorta, or vena cava, is a rare but catastrophic complication of pelvic surgery. Compared to the muscular walls of the major arteries, the thin-walled veins, such as the external iliac vein, may be more prone to injury during a lymph node dissection. If injury occurs, direct pressure should be applied. This allows time to allow adequate exposure for repair, to call for blood products, and to call a consulting surgeon if needed. If a major catastrophic vascular injury occurs to the aorta or iliac vessels during laparoscopy with a trocar or veress needle, a vertical exploratory laparotomy should be performed. Pressure should be placed over the area with a laparotomy sponge to tamponade the hemorrhage until vascular surgeons are available.
Hemorrhage
Intraoperative hemorrhage is defined as blood loss exceeding 1000 mL or blood loss of more than 25% of the patient’s blood volume. At the onset of heavy or uncontrolled bleeding, the first step is to apply pressure to the site either with a finger or a moist laparotomy sponge. Good communication with the surgical team, including the anesthesiologist and scrub and circulating nurses, is essential in responding to a hemorrhage and calling for blood products if needed.
Once pressure has been applied, the sponges should be removed slowly in attempt to visualize the bleeding vessels. Knowledge of the pelvic anatomy is crucial to avoid damage to the surrounding major vessels, nerves, and ureter. After identification of vital structures in the surrounding area, the bleeding vessels should be isolated and ligated. Specific areas prone to hemorrhage include the retroperitoneum during lymph node dissections, dissection close to the uterine artery during hysterectomy, and dissection in the presacral space, which can cause bleeding from presacral venous plexus during abdominal sacral colpopexy.
A technique that may control hemorrhage is hypogastric artery ligation or internal iliac artery ligation. This will decrease the pulse pressure at the distal bleeding site. Another technique that may be useful in controlling hemorrhage after caesarean section is bilateral uterine artery ligation by placing a large stitch through the uterine wall at the level of the cervical isthmus to ligate the uterine artery. During this technique, one must be careful of the ureter running inferior to the uterine artery. Topical hemostatic agents, cautery, clips, and sutures may also control the bleeding.
Goustout BS, Cliby WA, Podratz KC. Prevention and management of acute intraoperative bleeding. Clin Obstet Gynecol 2002;45:481–491. PMID: 12048406.
Stany MP, Farley JH. Complications of gynecologic surgery. Surg Clin North Am 2008;88:343–359. PMID: 18381117.
NEUROLOGIC INJURY
Incorrect positioning of a patient while under anesthesia can cause significant neurologic injury resulting in sensory and motor deficits. These complications are rare, usually transient, and usually resolve spontaneously with minimal intervention. However, long-term disability occasionally occurs. During pelvic surgery, injury can involve components of the lumbosacral nerve plexus, specifically the femoral nerve, the obturator nerve, the sciatic nerve, the iliohypogastric nerve, the ilioinguinal nerve, the genitofemoral nerve, the lateral femoral cutaneous nerve, and the pudendal nerve.
Gynecologic surgery is the most common cause of iatrogenic femoral nerve injury. Injury can occur with prolonged compression by retractor blades, when the hip is hyperflexed and hyperabducted in lithotomy position or due to direct injury associated with surgical dissection. Injury most commonly occurs when self-retaining retractors rest on the psoas muscle compressing the femoral or genitofemoral nerves. Symptoms from impaired motor function of the femoral nerve include weakness or inability to flex at the hip or extend at the knee. Sensory impairment includes paresthesia over the anterior and medial thigh and medial aspect of the calf. The obturator nerve may be injured during retroperitoneal dissection, such as lymph node dissection for gynecologic malignancies. This nerve injury will present with sensory loss in the upper medial thigh and motor weakness in hip adductors.
Other nerves compromised during incorrect positioning in lithotomy include the sciatic and peroneal nerves. Sciatic nerve compression and stretch occur with prolonged hyperflexion of the thigh. The common peroneal nerve courses across the lateral head of the fibula and therefore is susceptible to compression injury if the lateral aspect below the knee rests firmly against lithotomy stirrups. As for positioning of the upper extremities during gynecologic surgery, care should be taken to avoid hyperabduction to minimize risk for brachial plexus injury.
Two nerves at risk during a low transverse abdominal incision are the ilioinguinal and iliohypogastric nerves. They are susceptible to injury when a Pfannenstiel incision is extended beyond the border of the oblique muscle, and they also can be incorporated into the fascial repair resulting in nerve entrapment syndrome. This can cause a sharp burning pain or paresthesia over the nerve distribution. Therefore, careful positioning and placement of retractor blades are the best defenses against neurologic injuries.
Irvin W, Andersen W, Taylor P, et al. Minimizing the risk of neurologic injury in gynecologic surgery. Obstet Gynecol 2004;103:374–382. PMID: 14754710.
POSTOPERATIVE COMPLICATIONS
ACUTE HEMORRHAGE
Acute hemorrhage in the postoperative period can occur after many different procedures. This may occur as a result of an unrecognized trocar injury to the inferior epigastric vessels, a high cervical laceration from a dilatation and curettage, or a loose suture on a uterine artery pedicle after vaginal hysterectomy. In the recovery room, if a patient is persistently hypotensive despite fluid resuscitation, an internal hemorrhage should be suspected. One should respond by resuscitating the patient, checking blood count and coagulation studies, and ordering blood products for transfusion. If the patient does not respond, the patient may need to return to the operating room. Emergent uterine artery embolization has also shown to be a successful technique for postoperative bleeding.
THROMBOEMBOLIC COMPLICATIONS
1. Deep Vein Thrombosis
DVT is a serious and potentially preventable complication of major gynecologic surgery. Patients at increased risk include those with malignancy, obesity, immobility, previous VTE, thrombophilia, smoking, estrogen-containing hormone therapy use, and increasing age. Untreated DVT can lead to a fatal pulmonary embolus.
ESSENTIALS OF DIAGNOSIS
Diagnosis can usually be made with compression ultrasonography.
If ultrasonography is negative but there is still a high suspicion for DVT, contrast venography is the gold standard and should be performed.
Clinical Findings
A careful history and physical is important in the diagnosis of DVT. Patients usually present complaining of unilateral leg swelling and calf or leg pain. Physical exam may reveal ipsilateral leg edema, calf tenderness, warmth, or erythema. During the exam, a cord can be palpated indicating a thrombosed vein. Homan’s sign is pain with dorsiflexion of the foot. However, this sign is unreliable. A discrepancy in the calf diameter can be of some value in raising the suspicion for DVT.
Treatment
Patients with DVT should be treated with anticoagulants immediately. This is done as soon as DVT is confirmed by objective testing. If there is a delay in diagnostic testing and the clinical suspicious is high, therapy should be started before such testing. Several options are available for the initial treatment of DVT according to the American College of Chest Physicians Guidelines: (1) LMWH, administered subcutaneous, without monitoring; (2) intravenous (IV) UFH, with monitoring; (3) subcutaneous UFH, with monitoring; (4) weight-based subcutaneous UFH, without monitoring; and (5) subcutaneous fondaparinux, without monitoring. For those treatments requiring monitoring, coagulation studies such as INR and partial thromboplastin time (PTT) should be measured at baseline. With UFH, the PTT should be kept 1.5–2.5 times the control value.
Anticoagulation therapy is continued for 3–6 months. Therefore, oral anticoagulants, particularly warfarin, are often started at the same time as initial treatment with the LMWH or UFH therapies above. Oral anticoagulants do not exert their full effect for 48–72 hours. Warfarin is generally started a dose of 5 mg daily, and subsequent doses are adjusted to maintain the INR value at 2.5 (range 2.0–3.0). Therefore, the LMWH or UFH therapy is continued for at least 5 days until the warfarin takes effect and the INR is ≥2.0 for 24 hours. For patients in whom bleeding is a particular risk or laboratory monitoring is problematic, LMWH can be used for long-term treatment instead of warfarin. Due to more predictable pharmacokinetics, LMWH, such as enoxaparin, can be administered subcutaneous once or twice daily without laboratory monitoring in the majority of patients. This treatment, as well as oral anticoagulation, allows initial treatment of DVT as an outpatient. Recommended long-term therapy for distal or calf vein thrombosis includes 3 months of anticoagulation. Long-term treatment for a proximal DVT is 3–6 months of anticoagulation.
Surgical treatment, such as thrombectomy, occasionally can be considered for persistent severe swelling in the extremity. An inferior vena cava filter can be placed for patients who develop DVT or pulmonary embolism that occurs despite adequate anticoagulation or in patients who have contraindications to anticoagulation therapy.
2. Pulmonary Embolism
Laboratory and radiologic imaging is helpful in evaluating a patient for a pulmonary embolus (PE). With arterial blood gas, a low arterial Po2 should raise suspicion for a PE. D-dimer assays are usually elevated and have a high negative predictive value in ruling out a PE. However, recent surgery can elevate D-dimer levels and, therefore, may have little value in the workup.
Chest radiograph findings frequently show no abnormalities. However, a peripheral lung density, enlargement of the main pulmonary artery, or a small pleural effusion can be seen. Chest radiograph can rule out other diagnoses on the differential, such as pneumonia. Electrocardiogram is helpful in ruling out myocardial infarction. It can also show characteristic changes of PE, such as S1Q3T3 patterns, right bundle branch block, and T-wave inversions in leads V1 through V4.
Spiral chest computed tomography (CT) is now the diagnostic procedure of choice for PE. It can frequently visualize the emboli and has high sensitivity and specificity. Pulmonary angiography is the “gold standard” test but is used less frequently given it is an invasive procedure. It is reserved in patients with a high clinical suspicion for PE despite a negative or nondiagnostic spiral CT. Another imaging modality is the ventilationperfusion (V/Q) scan. It is not the tests of choice because the results are frequently equivocal. It is useful in diagnosis in patients who cannot receive IV contrast.
Clinical Findings
PE is a potentially fatal complication of gynecologic surgery and usually occurs suddenly as a complication of a pelvic or lower extremity DVT. Risk factors are the same as noted earlier for DVT. Symptoms usually occur abruptly and include pleuritic chest pain, dyspnea, tachypnea, and tachycardia. A large embolus may result in hypotension, shock, and even sudden death from cor pulmonale. The symptoms are not specific for PE, and the differential diagnosis includes atelectasis, pneumonia, myocardial infarction, and pneumothorax.
Prevention
There is ample evidence that primary thromboprophylaxis reduces DVT and PE and that fatal PE can be prevented. Recommendations based on guidelines from the American College of Chest Physicians include prophylaxis with low-dose UFH, LMWH, or intermittent pneumatic compression (IPC) devices for the extremities. For a low-risk patient undergoing a brief procedure <30 minutes, prophylaxis is not necessary. For brief procedures and laparoscopy, in patients who have risk factors for VTE, prophylaxis may be indicated. During any major gynecologic procedure, prophylaxis is recommended with low-dose heparin twice daily; LMWH, such as enoxaparin, once daily; or IPC. This prophylaxis is started just prior to surgery and is used continuously until discharge. For patients with malignancy, who are particularly at high risk, the recommendation is to continue prophylaxis with LMWH once daily or low-dose heparin 3 times daily for 2 to 4 weeks after discharge.
Treatment
Cardiopulmonary resuscitation should be instituted if necessary, and the patient should be closely monitored. Due to the risk of mortality, patients with strong clinical suspicion of PE should get immediate treatment with anticoagulation. Treatment regimens for DVT and PE are similar given they are manifestations of the same disease process and are described earlier.
According to the American College of Chest Physicians and their guidelines, in patients with acute nonmassive PE, recommendations include initial treatment with LMWH over IV UFH. In patients with massive PE, where there is concern for subcutaneous absorption, the guidelines suggest IV UFH over LMWH. For patients with a massive PE with evidence of hemodynamic compromise, thrombolytic therapy with urokinase, streptokinase, or recombinant tissue plasminogen activator is also recommended in addition to anticoagulation. Patients who are highly compromised and cannot receive thrombolytic therapy due to bleeding risks may be candidates for surgical pulmonary embolectomy.
ACOG Practice Bulletin No. 84: prevention of deep vein thrombosis and pulmonary embolism. Committee on Practice Bulletins–Gynecology, American College of Obstetricians and Gynecologist. Obstet Gynecol2007;110(2 Pt 1):429–440. PMID: 17666620.
Geerts WH, Bergqvist D, Pineo GF, et al. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th edition). Chest 2008;133:381S–453S. PMID: 18574271.
Kearon C, Kahn SR, Agnelli G, et al. Antithrombotic therapy for venous thromboembolic disease: College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th edition). Chest2008;133:454S–545S. PMID: 18574272.
GASTROINTESTINAL TRACT COMPLICATIONS
1. Ileus
Ileus is defined as a pattern of bowel dysmotility that results in accumulation of gas and fluid in the gastrointestinal tract. During abdominal or pelvic surgery, there usually is some degree of ileus for 3–6 days postoperatively. This is due to an increase in sympathetic tone, which causes inhibition in bowel motility. Bowel manipulation during surgery causes an inflammatory reaction resulting in an ileus. Opiate pain medications also have an inhibitory effect and can prolong an ileus.
Clinical Findings
The patient usually complains of abdominal pain and may have nausea or vomiting. Clinical findings include abdominal distention with decreased or absent bowel sounds. On plain abdominal radiographs, there is generalized dilatation and gaseous distention of both the small and large bowel.
Treatment
If nausea, vomiting, and abdominal distention are severe, the patient should be restricted of oral intake. A nasogastric (NG) tube should also be inserted into the stomach. IV fluids should be administered, and electrolytes should be monitored. Although an NG tube is sometimes used for treatment, routine use in all patients does not prevent ileus. Early feeding in the postoperative period does not cause ileus and shortens hospital stays. Thoracic epidural analgesia use postoperatively has shown to promote quicker return to bowel function. The use of NSAIDs and opioid receptor antagonists has not been proven to decrease ileus.
2. Small Bowel Obstruction
Small bowel obstruction can result as a complication of an intraperitoneal operation. This is usually due to the formation of adhesions, which can trap or kink a segment of small intestine. Other causes include herniation through a laparoscopic trocar site, internal herniation, or an inflammatory process such as an abscess. Obstruction can occur in the immediate postoperative period or several years later due to dense adhesions. This results in partial or complete bowel obstruction and can cause bowel strangulation and perforation.
Plain abdominal radiographs are very sensitive in the diagnosis of small bowel obstruction. They usually reveal air-fluid levels of differential height within the same loop of bowel. In patients with inconclusive radiograph films, a CT scan (with IV and oral contrast) is sensitive and specific and can give incremental information on the grade of obstruction. Signs of bowel obstruction or strangulation on CT include continuous dilation of proximal small bowel with a discrete transition zone, serrated beak sign, mesenteric fluid and ascites, and intraluminal fluid. The colon usually contains little or no gas. Enteroclysis or small bowel follow-through study with oral contrast, as well as CT enterography and magnetic resonance imaging (MRI) contrast studies, are also available as diagnostic tests.
Clinical Findings
Obstruction is characterized by abdominal pain, vomiting, abdominal distention, and obstipation. On examination, the abdomen is distended and tender with high-pitched bowel sounds. It can be difficult to differentiate from a postoperative ileus and may require diagnostic studies.
Treatment
Small bowel obstruction requires immediate intervention to prevent bowel ischemia and infarction. If the patient has no signs of bowel strangulation or peritonitis, conservative treatment can be used. This includes bowel rest, IV fluid hydration, electrolyte replacement, and bowel decompression with an NG tube. Patients with leukocytosis, fever, peritonitis, metabolic acidosis, and continuous pain suggest bowel strangulation and require operative intervention. In patients who received conservation management, if there is no improvement in symptoms within 48 hours, operative intervention is recommended with either exploratory laparotomy or laparoscopy.
3. Constipation
Constipation and a reduction in the number of bowel movements are expected in the early postoperative period given low food intake, ileus, and narcotic use. If a bowel obstruction is not suspected, stool softeners and mild laxatives can be prescribed. An enema can also be used. Fecal impaction can also be present and cause diarrhea in the postoperative patient. It is diagnosed by digital rectal examination, and treatment involves disimpaction of the firm fecal masses.
4. Diarrhea
Pathogenesis
Most postoperative diarrhea is caused by antibiotic administration or oral contrast for radiographic studies. This is usually mild and self-limiting. Antibiotics can alter the bacterial flora in the gastrointestinal tract. If overgrowth with Clostridium difficile occurs, a more serious infection can occur. C difficile may be a complication after treatment with antibiotics such as clindamycin, penicillins, cephalosporins, or fluoroquinolones. If untreated, C difficile infection can progress to fulminant colitis, ileus, obstruction, perforation, and toxic megacolon; therefore, prompt diagnosis and treatment are essential.
Clinical Findings
Clinical findings include diarrhea, fever, and leukocytosis. If C difficile infection is suspected, the stool should be sent for cytotoxin assay. If the infection is strongly suspected despite negative toxin stool toxin assays, colonoscopy can be performed to detect pseudomembranous changes in the colon. Toxic megacolon is a clinical diagnosis based on dilatation of the colon >7 cm on plain films, accompanied by severe systemic toxicity.
Treatment
C difficile is becoming increasingly pathogenic and contagious. Once diagnosed, the patient should be placed in isolation with infection precautions. Management includes first withdrawal of the implicated antibiotic, and then treatment with preferably oral metronidazole or vancomycin. However, oral metronidazole is preferred in order to reduce vancomycin resistance and to reduce cost. If the infection is unresponsive to antibiotics and progresses to toxic megacolon, surgical intervention with colectomy may be necessary.
Diaz JJ Jr, Bokhari F, Mowery NT, et al. Guidelines for management of small bowel obstruction. J Trauma 2008;64:1651–1664. PMID: 18545135.
Hookman P, Barkin JS. Clostridium difficile associated infection, diarrhea and colitis. World J Gastroenterol 2009;15:1554–1580. PMID: 19340897.
Stewart D, Waxman K. Management of postoperative ileus. Am J Ther 2007;14:561–566. PMID: 18090881.
URINARY TRACT COMPLICATIONS
1. Urinary Retention
Postoperative urinary retention is the inability to void in the presence of a full bladder. Risk factors for development of postoperative urinary retention include prolonged duration of surgery and the use of regional anesthesia or epidural analgesia. The patient may complain of suprapubic discomfort with the inability to void. The bladder may be palpable on abdominal exam if severely distended. Retention is likely if the patient is unable to void within 8 hours after surgery or 8 hours after bladder catheter removal. The diagnosis is confirmed if a bladder ultrasound displays 500 mL of urine or if a postvoid residual is 500 mL or greater. If retention is present, complications and bladder dysfunction may result. An overdistended bladder can cause pain and an autonomic response, resulting in vomiting, hypotension, bradycardia, and cardiac dysrhythmias. Infection can also be a direct complication or an indirect complication due to an indwelling bladder catheter. Severe overdistention for prolonged periods may cause ischemia and long-term bladder dysfunction.
Treatment
Standard treatment for retention is immediate bladder drainage with sterile catheterization. Although intermittent in-out catheters are an alternative, most patients have an indwelling bladder catheter placed while in the hospital. The catheter is placed for approximately 24 hours, and then a void trial is performed. With incontinence procedures, such as suburethral slings, there may be retention due to overcorrection of the bladder neck requiring outpatient treatment with a catheter for several days.
2. Urinary Tract Infection
In the immediate postoperative period, patients are at risk for urinary tract infection (UTI). They are at risk of UTI due to urinary retention that follows surgery and anesthesia, as well as due to instrumentation or catheterization during surgery. Catheter-associated UTI is one of the most common nosocomial infections.
Cystitis and UTI can cause increased frequency of urination, urgency, and dysuria. White blood cells, leukocyte esterase, and nitrites can be seen on urine analysis. When fever is present, pyelonephritis should be considered. If untreated, pyelonephritis can progress to urosepsis.
In patients suspected of having a UTI, a urine specimen should be sent for culture. Appropriate antibiotic therapy should be instituted and adjusted based on culture and sensitivity results. In patients with urinary retention, a bladder catheter is recommended. However, in patients without urinary retention, removal of the bladder catheter at the earliest possible time is important in treating and preventing UTIs.
3. Lower Urinary Tract Fistula
A lower urinary tract fistula is a rare complication of gynecologic surgery and obstetric trauma. These fistulas include vesicovaginal and ureterovaginal fistulas. Risk factors for fistula include malignancy, radiation therapy, intraoperative injury to bladder or the ureter, and obstructed labor. Most lower urinary tract fistulas in the Unites States occur after hysterectomies.
A lower urinary tract fistula can present perioperatively as gross hematuria or urinoma noted after surgery. In the postoperative period, patients with fistulas usually present 1 to 3 weeks after surgery complaining of urinary incontinence or persistent vaginal discharge. A speculum exam may reveal a fluid collection in the vagina and scarring at the apex. If a vesicovaginal fistula cannot be seen, a “tampon test” can be performed in the clinic. This test is performed by instilling methylene blue transurethrally into the bladder after placing vaginal sponges or a tampon in the vagina. The patient is then asked to walk around and perform the Valsalva maneuver. Intravenous indigo carmine or oral phenazopyridine can be given to exclude an ureterovaginal fistula. A voiding cystourethrogram can also be performed to diagnose and evaluate the size and location of a vesicovaginal fistula.
Cystoscopy is indicated in all cases to evaluate the size, location, and number of fistulas and the condition of the tissue. Radiologic imaging such an IVP or cystoscopic retrograde urogram is recommended to exclude a ureterovaginal fistula or hydronephrosis.
If a vesicovaginal fistula is diagnosed early, conservative management can be attempted. Although the timing, fistula size, and success rate remain unclear, limited data suggest that fistulas less than 1 cm in size diagnosed within 3 weeks of surgery can close spontaneously after bladder drainage. In 1 study, 39% of fistulas closed with bladder drainage if diagnosed within 3 weeks of surgery, while only 3% closed if diagnosed greater than 6 weeks after surgery. The duration of bladder drainage remains unclear, but some authors recommend 4 weeks of continuous drainage.
Ureteral fistulas are usually treated with ureteral stents for 6 to 8 weeks. An IVP is performed after 4 to 6 weeks to evaluate if the fistula has healed. If the fistula has healed, the stent is removed and IVP is performed at 3, 6, 12, and 24 months to rule out stricture formation. If the fistula has not healed, the stent is left in place for 8 weeks and the IVP repeated. If the fistula is not healed in 8 weeks, surgical repair is recommended.
The timing of vesicovaginal fistulas is controversial. Ideally, the fistula should be repaired within 72 hours of injury, before inflammation and induration take place. Some surgeons recommend waiting 3 to 6 months until the fistula has matured. Other surgeons have successfully closed fistulas earlier, after the initial inflammation has subsided. Timing of surgical repair should be individualized and based on cystoscopic evidence of healing, including the fistula site and adjacent tissue being pliable, noninflamed, epithelialized, and free of granulation tissue and necrosis. Vesicovaginal fistulas can be repaired vaginally or abdominally, but the surgical technique is beyond the scope of this chapter.
Baldini G, Bagry H, Aprikian A, et al. Postoperative urinary retention: anesthetic and perioperative considerations. Anesthesiology 2009;110:1139–1157. PMID: 19352147.
Bazi T. Spontaneous closure of vesicovaginal fistulas after bladder drainage alone: a review of the evidence. Int Urogynecol J Pelvic Floor Dysfunct 2007;18:329–333. PMID: 17036168.
Karram MM. Lower urinary tract fistulas. In Walters MD, Karram MM, eds. Urogynecology and Reconstructive Surgery. 3rd ed. Philadelphia, PA: Mosby Elsevier; 2007.
INFECTIOUS COMPLICATIONS
Bacterial contamination of the operative site is a common occurrence in major gynecologic surgery. Hysterectomies are classified as “clean contaminated” cases due to the entrance into the genital tract and contamination with endogenous vaginal flora. Although antibiotic prophylaxis decreases the risk of postoperative infection, it still remains one of the most common postoperative complications. The diagnosis of a postoperative infection is generally made when there is pain and tenderness in the area contiguous with the infection and an oral temperature of ≥38°C on 2 separate occasions at least 6 hours apart or of >38.5°C at any time.
Prevention
Antibiotic prophylaxis is usually only indicated for hysterectomy and urogynecology procedures. Cefazolin (1 g) is the most commonly used agent and is given within 30 minutes of the start of the procedure. A second dose of intraoperative antibiotic may be given if the duration of the surgery approaches 3 hours or in cases with increased blood loss (>1500 mL). Doxycycline is also used before and after surgical abortion. For procedures such as laparoscopy or exploratory laparotomy that do not directly enter the genital tract, antibiotic prophylaxis is not indicated.
1. Hematoma & Pelvic Abcess
Clinical Findings
An abscess should be considered in the postoperative patient with fever and no other source or in a patient who has failed initial antibiotic treatment. The patient usually presents with fever and abdominal pain. Clinical findings may include a mass palpated on pelvic examination. Pelvic hematomas that become infected can also present in a similar manner.
Treatment
If an abscess is suspected, imaging should be performed with ultrasound or a CT scan with contrast. If confirmed, treatment involves parenteral antibiotics. Some regimens include gentamicin and clindamycin; ampicillin, gentamicin, and metronidazole; imipenem/cilastatin; and levofloxacin and metronidazole. Parenteral antibiotics are continued until the patient has been afebrile for 24 to 48 hours, and then patients are switched to oral antibiotics. Many abscesses, especially large ones, require drainage for adequate treatment. Percutaneous drainage of the fluid collection is often possible with insertion of a large-caliber “pigtail” catheter under ultrasound or CT guidance. An infected cuff hematoma or abscess can sometimes be managed by reopening the cuff. If the abscess does not respond to the above treatment, the patient may need a laparotomy with opening of the abscess, irrigation, and drain placement.
2. Wound Infection
A wound infection is usually localized to the skin and fatty tissue above the fascia. The diagnosis of a postoperative wound infection is usually made several days after surgery, on postoperative day 4 or 5.
Clinical Findings
With wound infections or cellulitis, skin erythema (redness and warmth), subcutaneous induration, and fever are usually present. If there is incisional drainage present, there may be an abscess or fluid collection beneath the incision.
Treatment
Cellulitis alone is usually treated with a single agent that is effective against streptococci, staphylococci, and most gramnegative organisms, such as a cephalosporin. If there is a fluid collection presenting with purulent drainage from the wound, it should be opened to allow drainage and debridement if necrotic tissue is present. The wound should be gently probed to check for fascial integrity. If the fascia is intact, the wound should be packed with moist gauze dressings 2 or 3 times daily.
3. Wound Dehiscence & Evisceration
Wound dehiscence is a postoperative wound separation that involves all layers of the abdominal wall. Risk factors include age, malnutrition, diabetes, smoking, malignancy, chronic steroid use, and obesity. Wound infection also predisposes the wound to disruption. Evisceration includes disruption of these layers with protrusion of intestines through the incision. The hallmark of this complication is profuse serosanguinous discharge from the abdominal incision. This is a surgical emergency that requires immediate closure in the operating room.
4. Necrotizing Fasciitis
ESSENTIALS OF DIAGNOSIS
Diagnosis is based on physical findings of a rapidly progressing infection.
Radiologic tests, such as CT, MRI, or plain films, will display gas in the subcutaneous tissue.
Surgical exploration will confirm the diagnosis, which reveals necrotic subcutaneous tissue and fasciae.
Pathogenesis
Necrotizing fasciitis is a rare and often fatal infection that is characterized by extensive necrosis of the fascia and adjacent subcutaneous tissue. Predisposing factors include advanced age, obesity, hypertension, arteriosclerosis, diabetes, malnutrition, renal failure, immunosuppression, and trauma. The bacteria that cause these infections include group A Streptococcus and other anaerobes such as Clostridium perfringens.
Clinical Findings
The clinical triad includes sepsis, inordinate pain, and unilateral edema. On physical examination, patients may appear septic with a fever and leukocytosis. The skin around the incision site is usually cool, gray, and boggy, and may reveal crepitus. Usually, the wound will display a marked degree of subcutaneous edema and varying degrees of cutaneous discoloration. There also may be a sensory deficit over the area of infection.
Treatment
The most important treatment includes early and aggressive surgical debridement of the infection. This includes removal of all the necrotic tissue that is not bleeding and discolored. Healing is usually by secondary intention, with skin grafts often being necessary. Therefore, a gynecologic oncologist or plastic surgeon is usually involved. Treatment also includes broad-spectrum antibiotics, including a penicillin. Hyperbaric oxygen treatment can also lead to a decrease in the morbidity of these infections.
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Gallup DG, Freedman MA, Mequiar RV, et al. Necrotizing fasciitis in gynecologic and obstetric patients: a surgical emergency. Am J Obstet Gynecol 2002;187:305–310. PMID: 12193917.
Larsen JW, Hager WD, Livengood CH, et al. Guidelines for the diagnosis, treatment and prevention of postoperative infections. Infect Dis Obstet Gynecol 2003;11:65–70. PMID: 12839635.