Anesthesia and Surgery Considerations for Patients with Liver Disease

The liver is the largest internal organ and performs a vast array of functions, including filtering venous blood from the digestive tract, metabolizing nutrients and drugs, detoxifying and excreting toxins, and synthesizing blood proteins. Liver disease impairs these processes, and as a result, operating on patients with liver disease involves important anesthesia and surgery considerations to ensure that their unique risks are addressed.¹

Changes in blood flow and intraoperative blood loss during surgery put liver disease patients at particularly high risks for complications. Preoperative risk stratification can help physicians identify the risks specific liver disease patients face. Elective surgeries are contraindicated in a number of clinical scenarios, particularly for patients with acute liver failure, acute viral or alcoholic hepatitis, severe coagulopathy, and certain other conditions. For patients that can undergo surgery, the Child-Turcotte-Pugh score and the Model for End-Stage-Liver Disease (MELD) score are commonly used to stratify risks. They have each been correlated with 30-day mortality. For example, every MELD score-point increase above 8 was associated with a 14 percent increase in mortality in the first 30 to 90 days post-operation in one study of 772 liver disease patients undergoing digestive, orthopedic, or cardiovascular surgeries.²

Those with liver disease generally have scarring and fibrosis in the liver, causing oxygen deficiencies that prompt increases in blood pressure in the portal venous system (the vessels that lead to the liver).³ In more extreme cases, patients develop cirrhosis, characterized by decreased systemic vascular resistance. Anesthetic agents reduce blood flow to the liver, which if improperly managed, could result in the death of the damaged liver tissue.² Halothane has been shown to result in a particularly prominent decrease in hepatic blood flow,⁴ while the inhalation agents sevoflurane, desflurane, and isoflurane have been shown to better maintain it.³ Among intravenous anesthetic agents, propofol increases total hepatic blood flow and has a short half-life, even in patients whose liver function is compromised, and it is generally acceptable to use in patients with cirrhosis.^3,4,5

The half-life of narcotics and sedatives is an important factor when operating on patients with liver disease due to the possibility of prolonged or disrupted metabolism of medications. While patients with cirrhosis can largely still eliminate fentanyl, the half-life of alfentanil is almost doubled. Opioids such as morphine have a prolonged elimination half-life as well. Muscle relaxants like vecuronium and rocuronium are metabolized in the liver and can therefore also have prolonged effects. Overall, dose adjustments for these medications and others are critical for patients with liver disease.³

Patients with advanced liver disease are unable to synthesize both clotting and anticlotting factors, making them prone to bleeding and thrombosis simultaneously.⁴ Rahimzadeh et al. note that coagulation management in this specific population parallels that in other patient populations, with thromboelastography being a useful test to identify the cause and characteristics of clot formations and reduce the necessity of transfusions in cirrhotic patients.^2,3

Post-operatively, cirrhosis patients may be at risk for hepatic decompensation. This may be characterized by encephalopathy, coagulopathy, ascites, or exacerbated jaundice. Renal function must also be closely monitored.¹ Patients with liver disease — especially those with cirrhosis who are undergoing operations requiring general rather than regional anesthesia — are overall at increased risk for surgical complications. The degree of liver disfunction, type of surgery, and clinical state of the patient all influence risk levels. Collaboration between hepatologists, anesthesiologists, and surgeons can improve the prediction and management of these potential complications, thereby reducing the incidence of poor outcomes.⁶

References

1. Friedman LS. The risk of surgery in patients with liver disease. Hepatology. 1999;29(6):1617-1623. doi: 10.1002/hep.510290639
2. Dalal A, Lang JD Jr. Anesthetic considerations for patients with liver disease. In: Abdeldayem H, ed. Hepatic Surgery. InTech; 2013. doi: 10.1002/hep.510290639
3. Rahimzadeh P, Safari S, Faiz SHR, Alavian SM. Anesthesia for patients with liver disease. Hepat Mon. 2014;14(7):e19881. doi: 10.5812/hepatmon.19881
4. Prenner S, Ganger D. Risk stratification and preoperative evaluation of the patient with known or suspected liver disease: Evaluation of Known or Suspected Liver Disease. Clin Liver Dis (Hoboken). 2016;7(5):101-105. doi: 10.1002/cld.546
5. Propofol. In: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury. National Institute of Diabetes and Digestive and Kidney Diseases; 2020.
6. Aminnejad R, Alemi F, Safari S, et al. Preoperative considerations in patients with advanced liver disease. Middle East J Dig Dis. 2019;11(4):237-239. doi: 10.15171/mejdd.2019.156