HEPATIC AND GI SYSTEMS PART II

1. HEPATIC AND GI SYSTEMSPART II DENNIS STEVENS CRNA, MSN, ARNP OCTOBER 2007 FLORIDA INTERNATIONAL UNIVERSITY ADVANCED BIOSCIENCE IN ANESTHESIOLOGY II NRG 6145

2. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE OBJECTIVES • Discuss the etiology of hepatitis and related clinical manifestations. • Explain the causes of cirrhosis and associated clinical signs and symptoms. • Describe the anesthetic technique and anesthetic management when caring for a patient with cirrhosis of the liver. • Discuss intraoperative complications and anesthetic considerations of liver transplantation. • Explain etiology of GERD and anti-reflux surgical procedures that may be performed.

3. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE INTRODUCTION • Prevalence of liver disease is increasing • Cirrhosis major cause of death of men in their fourth and fifth decades of life • Ten percent of patients with liver disease undergo operative procedures during the final two years of life • Liver has remarkable functional reserve • Clinical manifestations of hepatic dysfunction are often absent until extensive damage has occurred • Effects from anesthetics and surgery can precipitate further hepatic decompensation in marginal patients with little reserve

4. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATITIS • Acute hepatitis: • Usually the result of viral infection, drug reaction, or exposure to hepatotoxin • Represents acute hepatocellular injury with variable amounts of cell necrosis • Clinical manifestations…! • Mild inflammatory reactions may present as asymptomatic elevations in serum transaminases • Massive necrosis presents as acute fulminant hepatic failure

5. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATITIS • Viral hepatitis: • Most commonly due to hepatitis A, B, or C viruses • Hepatitis types A and E transmitted by oral-fecal route. Types B and C are transmitted primarily percutaneously and by contact with body fluids. Hepatitis D may be transmitted by either route and requires the presence of hepatitis B • Epstein-Barr, HSV, CMV, and coxsackieviruses may also cause hepatitis • Clinical manifestations…Clinical course…!

6. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATITIS • Drug-induced hepatitis: • Can result from: • Direct dose-dependent toxicity of a drug • An idiosyncratic drug reaction • Course resembles viral hepatitis • May be associated with: • Alcohol consumption • Acetaminophen ingestion • Ingestion of potent hepatotoxins • Volatile anesthetics

7. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATITIS • Preoperative considerations: • Elective surgery should be postponed until acute episode has resolved • Patients with hepatitis are at risk for deterioration of hepatic function and development of complications from hepatic failure • Preoperative laboratory evaluation…! • Patient with acute hepatitis presenting for emergent surgery…!

8. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATITIS • Intraoperative considerations: • Goal of intraoperative management…! • Prolonged duration of action may be encountered with large or repeated doses of IV agents • Isoflurane is the anesthetic agent of choice • Factors known to reduce hepatic blood flow should be avoided • RA may be selected in the absence of coagulopathy, provided hypotension is avoided

9. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATITIS • Chronic hepatitis: • Defined as persistent hepatic inflammation for longer than six months, as evidenced by elevated serum aminotransferases • Patients usually classified as having a distinct syndrome based on liver biopsy: • Chronic persistent hepatitis • Chronic lobular hepatitis • Chronic active hepatitis

10. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Serious and progressive disease that eventually results in hepatic failure • Most common cause of cirrhosis is related to alcohol consumption (Laennec’s cirrhosis) • Other causes include: • Chronic active hepatitis • Chronic biliary inflammation or obstruction • Chronic right-sided CHF • Hemochromatosis • Wilson’s disease • Antitrypsin deficiency

11. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Hepatocyte necrosis is followed by fibrosis and nodular regeneration • Eventually portal venous flow is obstructed leading to portal hypertension • Clinically, signs and symptoms do not correlate with disease severity • Manifestations are initially absent • Jaundice and ascites eventually develop in most patients

12. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Cirrhosis is generally associated with development of three major complications: • Variceal hemorrhage from portal hypertension • Intractable fluid retention • Hepatic encephalopathy or coma • Some patients may present with spontaneous bacterial peritonitis, and some may develop hepatocellular carcinoma • Preoperative considerations: • Increased risk of deterioration of liver function • Successful anesthetic management…!

13. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Manifestations of cirrhosis: • Gastrointestinal: • Portal hypertension: • Ascites • Esophageal varices • Hemorrhoids • Gastrointestinal bleeding • Circulatory: • Hyperdynamic state • Systemic arteriovenous shunts

14. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Manifestations of cirrhosis: • Pulmonary: • Increased intrapulmonary shunting • Decreased functional residual capacity • Pleural effusions • Restrictive ventilatory defect • Renal: • Increased proximal/distal reabsorption of sodium • Impaired free water clearance: • Decreased renal perfusion • Hepatorenal syndrome

15. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Manifestations of cirrhosis: • Hematologic: • Anemia • Coagulopathy: • Hypersplenism • Thrombocytopenia • Leukopenia • Infectious: • Spontaneous bacterial peritonitis

16. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Manifestations of cirrhosis: • Metabolic: • Hyponatremia • Hypokalemia • Hypomagnesemia • Hypoalbuminemia • Hypoglycemia • Neurologic: • Encephalopathy

17. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Intraoperative considerations: • Patients with postnecrotic cirrhosis due to hepatitis B or C who are carriers of the virus may be infectious • Drug responses…! • Smaller than normal maintenance doses of neuromuscular blocking agents dependent on hepatic elimination are needed • There may be a prolonged duration of action for succinylcholine

18. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Anesthetic technique: • Liver very dependent on hepatic arterial perfusion • Administration of RA may be considered • Half-lives of opioids are often significantly prolonged • Cisatracurium may be neuromuscular blocking agent of choice • Must consider abdominal distention due to massive ascites

19. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Intraoperative monitoring: • Close respiratory and cardiovascular monitoring is necessary for patients undergoing abdominal procedures • Pulse oximetry supplemented with ABG analysis • N2O may not be tolerated • Consider use of PEEP • Intra-arterial monitoring indicated for most patients • CVP or PA catheter monitoring may be indicated • Urinary output must be monitored closely

20. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE CIRRHOSIS • Intraoperative fluid replacement: • Intraoperative preservation of intravascular volume and urinary output takes priority • Predominant use of colloids may be preferable to avoid sodium overload and increase oncotic pressure • Fluid replacement should take into account excessive bleeding and fluid shifts • Removal of ascitic fluid and volume replacement…! • Consider transfusing red blood cells

21. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATOBILIARY DISEASE • Often characterized by cholestasis • Most common cause extrahepatic obstruction of biliary tract • Patients present with progressive jaundice, dark urine with pale stools, and/or pruritis • Intrahepatic cholestasis most commonly results from viral hepatitis or an idiosyncratic drug reaction • Treatment for extrahepatic/intrahepatic cholestasis…! • Gallstone disease (cholelithiasis)…!

22. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATOBILIARY DISEASE • Preoperative considerations: • Patients present to the OR for cholecystectomy, relief of extrahepatic biliary obstruction, or both • Medical treatment…! • Evaluate PT with extrahepatic biliary obstruction • Intraoperative considerations: • Insufflation of CO2 into the abdomen and patient positioning can complicate anesthetic management • Opioids in relation to sphincter of Oddi…! • Invasive hemodynamic monitoring may be indicated

23. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATIC SURGERY • Overview: • Common hepatic surgical procedures include: • Repair of lacerations • Drainage of abscesses • Resections for tumors • Liver transplantation is also performed • Anesthetic management: • Consider potential large blood loss • Hemodynamic invasive monitoring indicated • Postoperative complications…!

24. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATIC SURGERY • Liver transplantation: • Only curative therapy for hepatic failure • Common indications for transplantation: • Fulminant disease • End-stage failure • Hepatoma • Biliary tract tumors • Genetic disturbances

25. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATIC SURGERY • Liver transplantation: • Preoperative disturbances: • Arterial hypoxemia • Anemia • Thrombocytopenia • DIC • Hypokalemia • CHF • Encephalopathy

26. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE HEPATIC SURGERY • Liver transplantation: • Anesthetic management: • Invasive monitoring and large bore IVs • Cell-saver and rapid infusion devices • Consider correcting any coagulopathies • Calcium administration • Avoid nitrous oxide • Intraoperative considerations: • Inferior vena cava clamping/unclamping • Pulmonary hypertension

27. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE POSTOPERATIVE JAUNDICE • Can result from a variety of factors • Correct diagnosis requires a careful review of preoperative liver function and review of intraoperative and postoperative events • Causes of postoperative jaundice: • Prehepatic (increased bilirubin production) • Hepatic (hepatocellular dysfunction) • Posthepatic (biliary obstruction)

28. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE GASTROESOPHAGEAL REFLUX DISEASE • Common clinical problem caused by chronic reflux of acidic gastric fluid into the esophagus • Underlying defect is a decrease in resting tone of lower esophageal sphincter

29. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE GASTROESOPHAGEAL REFLUX DISEASE • Medical treatment: • Initially with oral antacids • Avoidance of substances that decrease lower esophageal sphincter pressure • Surgical treatment: • GERD treated surgically when…! • Variety of anti-reflux surgical procedures performed • Procedures performed via thoracic or abdominal approaches, often laparoscopically • Valve mechanism is created by wrapping a gastric pouch around the distal esophagus

30. ANESTHESIA FOR PATIENTSWITH LIVER DISEASE REFERENCES Morgan, G.E., Mikhail, M.S., and Murray, M.J. (2006). Clinical Anesthesiology. (4th Ed.) New York, NY: McGraw-Hill. Nagelhout, J.J. and Zaglaniczny, K.L. (2005). Nurse Anesthesia. (3rd Ed.) St. Louis, MO: Elsevier- Saunders.