How to assess and manage patients with compromised liver function and impaired liver reserve?

Assessment and Management of Functional Liver Reserve

Assess functional liver reserve using a multiparametric approach combining Child-Pugh classification, MELD score, and additional objective measures including indocyanine green retention test (ICG-R15), liver stiffness measurement, and portal hypertension indicators to guide treatment decisions and predict outcomes. 1

Primary Assessment Tools

Child-Pugh Classification

• Child-Pugh score remains the most practiced method for measuring liver reserve, with Class A allowing liver resection within safe limits. 1
• The score incorporates serum albumin, bilirubin, prothrombin time/INR, and clinical assessments of encephalopathy and ascites. 1
• Patients with Child-Pugh Class B or C have decompensated cirrhosis and should be excluded from most interventions except liver transplantation. 1
• Advantages include ease of bedside performance and inclusion of clinical parameters, though it contains subjective elements. 1

MELD Score

• MELD score (using serum bilirubin, creatinine, and INR) provides superior objective assessment compared to Child-Pugh for predicting 90-day mortality and is the standard for liver transplant prioritization. 1, 2, 3
• MELD scores <10 indicate acceptable liver function for surgical resection in compensated cirrhosis. 1
• MELD has replaced Child-Pugh as the more commonly used system due to superior survival prediction ability and use of only objective laboratory criteria. 2, 3
• The score ranges from 6 (less ill) to 40 (gravely ill) and was adopted by UNOS for stratifying transplant waiting lists. 1, 3

MELD Variations

• MELD-Na incorporates serum sodium and may improve predictive accuracy, as sodium is an important prognostic predictor in cirrhosis. 2
• MELD score limitations include potential elevation of INR or creatinine from non-hepatic causes and gender differences in creatinine interpretation. 2, 3

Advanced Functional Assessment

Indocyanine Green (ICG) Test

• ICG retention rate at 15 minutes (ICG-R15) provides dynamic liver function assessment with specific cut-offs guiding extent of hepatectomy: ICG-R15 <20-25% allows major resection, <30-35% permits segmentectomy. 1
• ICG-R15 can be measured at bedside with non-invasive pulse dye densitometry after IV administration of 0.5 mg/kg body weight. 1
• ICG-R15 serves as a noninvasive predictor of portal hypertension in patients with different severity of cirrhosis. 1

Liver Stiffness Measurement (LSM)

• Transient elastography with liver stiffness >12-14 kPa predicts significant risk of post-hepatectomy liver failure and can estimate safe liver remnant volume. 1
• LSM provides non-invasive comprehensive assessment of fibrosis grade for liver resection planning. 1
• Combination of liver and splenic stiffness measurements with baseline platelet counts helps identify compensated cirrhosis patients with clinically significant portal hypertension. 1

ALBI Grade

• The albumin-bilirubin (ALBI) grade model considers serum albumin and bilirubin levels and is especially helpful in predicting survival outcomes in patients with stable decompensated cirrhosis. 1
• ALBI grade provides evidence for an improved model for liver functional estimation in hepatocellular carcinoma patients. 1

Portal Hypertension Assessment

Clinical Indicators

• Evaluate for clinically relevant portal hypertension (CRPH, defined as HVPG >10 mmHg) through esophagogastric varices, splenomegaly, splenorenal shunts, umbilical vein recanalization, and thrombocytopenia. 1
• Evidence of portal hypertension may be evident on CT/MRI imaging. 1
• Esophageal varices can be evaluated using esophagogastroduodenoscopy or contrast-enhanced cross-sectional imaging. 1

Hemodynamic Measurements

• Hepatic venous pressure gradient (HVPG) <10 mmHg with normal bilirubin indicates well-preserved liver function suitable for resection. 1
• Portal hypertension relevance as an independent determinant of post-surgical outcomes should be balanced with extent of hepatectomy and liver function indicators like MELD score. 1

Risk Stratification for Interventions

Surgical Candidacy

• Optimal surgical candidates require compensated Child-Pugh Class A with MELD <10, acceptable portal hypertension grade, adequate future liver remnant, and possibility of minimally invasive approach, targeting perioperative mortality <3% and morbidity <20%. 1
• Limited resection in patients with preserved liver function and moderate CRPH yields competitive survival outcomes. 1
• Simplified decisional algorithms using pre-surgical, non-invasive, objective parameters help predict risk of post-surgical decompensation. 1

ICU Admission Criteria

• Do not deny ICU admission solely based on underlying cirrhosis; use CLIF-SOFA score to identify Acute-on-Chronic Liver Failure (ACLF) with 28-day mortality ≥15%. 1
• SOFA and CLIF-SOFA scores (AUC 0.70-0.95 and 0.72-0.83 respectively) display better performance than general ICU scores (APACHE2, SAPS2) for predicting short-term mortality. 1
• ACLF grade based on organ failure better predicts ICU cirrhotic patient outcomes than MELD or Child-Pugh scores. 1

Monitoring Strategy

Laboratory Parameters

• Obtain complete liver panel including AST, ALT, alkaline phosphatase, total and direct bilirubin, albumin, and prothrombin time to assess cholestatic patterns and synthetic function. 4
• Monitor coagulation parameters, complete blood counts, metabolic panels, and arterial blood gases frequently in critically ill patients. 5
• Check creatinine clearance regularly as creatinine is an established prognostic marker in liver disease. 1

Clinical Follow-up

• Conduct clinical examination focusing on signs of liver and heart decompensation including jaundice, hepatic encephalopathy, lower limb edema, and dyspnea. 1
• Calculate Child-Pugh and MELD scores regularly for ongoing assessment of liver function. 1
• Monitor for hepatic encephalopathy using standardized scales such as West Haven classification; animal naming test can screen for minimal hepatic encephalopathy. 1, 5

Common Pitfalls and Caveats

Laboratory Interpretation

• Gilbert's syndrome can cause elevated total bilirubin; focus on direct bilirubin (normally <30% of total) when Gilbert's is present or suspected. 1
• Isolated ALP elevations are common with bone metastases or malignant biliary obstruction and should not be used alone for exclusion criteria. 1
• MELD includes creatinine which may represent different degrees of renal dysfunction in men versus women, potentially compromising fair organ allocation for female patients. 2

Treatment Considerations

• Avoid nephrotoxic drugs including NSAIDs as they worsen renal function in patients with compromised liver reserve. 5
• Do not routinely correct coagulation abnormalities unless active bleeding is present. 5
• Avoid benzodiazepines and psychotropic drugs as they worsen hepatic encephalopathy. 5

Prognostic Assessment

• Prognosis assessment is more accurate when performed a few days after ICU admission rather than on admission, as the number of failing organs evolves. 1
• Approximately 15-20% of patients' survival cannot be accurately predicted by MELD score alone. 6
• Neither MELD nor Child-Pugh correlates well with post-transplant resource utilization in critically ill patients. 7