In addition to risk stratification, optimal preoperative management of conditions related to an underlying hepatic dysfunction is essential ( Table 2 ). Particular attention needs to be paid to the management of common complications of advanced liver disease, such as coagulopathy, thrombocytopenia, ascites, renal insufficiency, encephalopathy, and malnutrition, as well as to disease-specific factors. For example, the predisposition of cirrhotic patients to infection warrants consideration of the use of prophylactic antibiotics to prevent sepsis.
The etiology of coagulopathy can be multifactorial; it can result from malnutrition, poor absorption of nutrients as a consequence of cholestasis, or impaired synthesis of coagulation factors. Intramuscular administration of vitamin K and transfusions of fresh, frozen plasma can be used to correct the patient's INR before surgery; however, it might not be possible to correct the INR by this method when coagulopathy is severe, and repeated transfusions of fresh, frozen plasma are associated with a large fluid load. Intravenous cryoprecipitate, which can be infused with a minimal volume load, contains large amounts of fibrinogen and von Willebrand factor in addition to clotting factors and can also be useful for correction of an underlying coagulopathy in patients with liver disease. Intravenous recombinant factor VIIa is a safe and effective means of correcting coagulopathy and normalizing the INR in patients with cirrhosis before some invasive procedures such as liver biopsy.[63,64,65] Intravenous recombinant factor VIIa is costly, however, and studies on its perioperative use in patients who underwent partial hepatectomy have not consistently demonstrated a benefit in terms of reducing the need for blood transfusions. For patients with pre-existing thrombocytopenia, transfusions of platelets to achieve a count of 100,000/mm3 or more are recommended. Prolonged bleeding times can be corrected using desmopressin acetate.
Aggressive preoperative management and control of ascites can minimize the risks associated with perioperative respiratory compromise and postoperative wound dehiscence. Long-term management involves dietary sodium restriction (to <2 g daily) and oral diuretic therapy with preoperative assessment of electrolytes and renal function. Although rarely symptomatic, hyponatremia is common in patients with advanced cirrhosis as well as in those receiving diuretic agents, and fluid restriction is occasionally warranted if the serum sodium concentration is less than 120 mmol/l. Rapid treatment options for moderate to severe ascites include large-volume paracentesis or removal of ascites during laparotomy. If paracentesis is performed, appropriate fluid analysis should be performed to rule out spontaneous bacterial peritonitisfor which, if present, appropriate antibiotic therapy should be initiated.
Postoperative reaccumulation of ascites is common and efforts should be made to minimize its occurrence. Preventive strategies include avoiding excessive oral intake of sodium, and minimizing the amount of saline in intravenous fluids used for drug administration or electrolyte replacement.
Recognizing and preventing renal dysfunction in patients with liver disease who are scheduled to undergo surgery is essential to minimize the development of perioperative complications. As the severity of chronic liver disease progresses, the pathophysiologic changes that occur predispose patients to hypoperfusion of the kidneys. The avoidance of agents that can cause nephrotoxic insult is, therefore, important; such agents include aminoglycosides, NSAIDs, and intravenous dye loads. Paracentesis volumes in excess of 5 l should be accompanied by intravenous albumin infusion to decrease the risk of postparacentesis circulatory and renal dysfunction.
Portosystemic encephalopathy (PSE) is a complication of liver disease that manifests as a wide array of neuropsychiatric symptoms that can range from mild confusion to deep coma. Although elevated serum ammonia levels are associated with PSE, the ultimate diagnosis is one of exclusion and should be based on clinical suspicion. PSE is often precipitated by a number of reversible factors, including metabolic derangements such as hypokalemia, alkalosis, hypoglycemia and hypovolemia, and medications, especially benzodiazepines. Patients with portal hypertension who develop gastrointestinal bleeding, renal failure and active infection (especially spontaneous bacterial peritonitis) are prone to develop PSE. In these patients, elective surgery should be postponed until the patient's mental status improves. Treatment of PSE consists of identifying the reversible etiologic factors and attempting to correct them.
Although several options exist for the treatment of PSE that are widely used in clinical practice, they suffer from a lack of evidence-based support. Oral lactulose, which decreases ammonia absorption in the large bowel by lowering the pH of luminal contents, is commonly used and has been shown to improve symptoms of PSE when compared with placebo. The lactulose dose is titrated until the goal of 34 soft stools per day is achieved. Oral rifaximin is of value, because of its lack of systemic absorption and high antibacterial activity; it can improve the symptoms of PSE and is useful for patients who are intolerant of lactulose. Other antibiotics such as neomycin, metronidazole, and vancomycin are rarely used because of concerns about adverse effects associated with their use. Some small studies reported a benefit with zinc supplementation, although these findings have not been confirmed in large studies.[74,75] Dietary protein restriction to 11.5 g/kg per day is often attempted, although there is no clinical evidence to support this practice and it has the potential to complicate the postoperative course in patients with pre-existing malnutrition. In patients for whom malnutrition and adequate oral intake is a concern, supplemental feeding with enteral tube feeds is often required, in part because of the increased catabolic rate observed in patients with cirrhosis.
The presence of either hepatopulmonary syndrome (HPS) or portopulmonary hypertension can complicate advanced liver disease and portends a poor survival. The presence of platypnea, orthodeoxia, right heart failure, hypoxemia (arterial PO2 <60 mmHg), or a postural change in arterial oxygen saturation as measured by pulse oximetry should raise clinical suspicion of HPS.[78,79] Contrast-enhanced echocardiography and 99mTc-labeled macroaggregated albumin lung perfusion scans provide useful screening tests for intrapulmonary vasodilatation in patients with suspected HPS, whereas Doppler echocardiography is useful to screen patients for portopulmonary hypertension.[80,81] There are no effective perioperative therapies that can improve the pulmonary vascular abnormalities, hypoxemia and ventilationperfusion mismatches associated with HPS, but various therapies can reduce pulmonary arterial pressures in patients with portopulmonary hypertension. The role of these therapies in preoperative management of patients scheduled for elective, nontransplant procedures is, however, unknown.
In patients with certain liver diseases, specific factors can influence the risks of surgery. Early retrospective studies indicated that there was a possible benefit conferred by preoperative external biliary drainage in patients with obstructive jaundice. Subsequent prospective, randomized studies have shown, however, that preoperative biliary drainage (either by percutaneous or endoscopic approaches) does not improve the perioperative morbidity or mortality of patients in whom there is no evidence of infection, and is, therefore, not recommended.[83,84,85,86] In situations where there is clinical concern for the development of acute cholangitis, rapid biliary decompression and intravenous antibiotics should be administered preoperatively, and surgery should be delayed until the infection resolves.
In patients with liver disease and ongoing significant alcohol use, a period of abstinence is recommended before surgery to avoid the development of withdrawal symptoms perioperatively. In addition, patients who consume a substantial volume of alcohol are at increased risk for the development of acetaminophen-induced hepatotoxicity, and caution should be used in the administration of postoperative analgesia.
In patients who have autoimmune liver disease and are taking more than 10 mg daily of prednisone, consideration should be given to the perioperative administration of high-dose, or 'stress' dose hydrocortisone, although there remains considerable debate as to the efficacy of this practice. Patients with hemochromatosis should be preoperatively evaluated for diabetes and cardiomyopathy, as these conditions can influence postoperative outcomes. In patients with Wilson's disease, penicillamine may impair postoperative wound healing, and the dose should be reduced 12 weeks before surgery. In addition, surgery may precipitate or worsen neurological symptoms.
Nat Clin Pract Gastroenterol Hepatol. 2007;4(5):266-276. © 2007 Nature Publishing Group
Cite this: Preoperative Evaluation of Patients With Liver Disease - Medscape - May 01, 2007.