What is the MELD score for a patient with a prothrombin time of 13.7 seconds (control 12.5 seconds) and a total bilirubin of 7 mg/dL, assuming a creatinine of 1 mg/dL?

MELD Score Calculation

For this patient with PT 13.7 seconds (control 12.5), total bilirubin 7 mg/dL, and assuming creatinine 1 mg/dL, the MELD score is approximately 18-19, which indicates significant liver disease with substantial short-term mortality risk and warrants immediate evaluation for liver transplantation. 1, 2

Calculation Method

The MELD formula is: MELD = 3.8 × ln(bilirubin mg/dL) + 11.2 × ln(INR) + 9.6 × ln(creatinine mg/dL) + 6.4 1, 2

Step-by-Step Calculation for This Patient:

First, convert PT to INR:

• PT ratio = Patient PT / Control PT = 13.7 / 12.5 = 1.096
• This PT ratio corresponds to an INR of approximately 1.1-1.2 1

Apply the MELD formula:

• Bilirubin component: 3.8 × ln(7) = 3.8 × 1.95 = 7.4
• INR component: 11.2 × ln(1.1) = 11.2 × 0.095 = 1.1
• Creatinine component: 9.6 × ln(1.0) = 9.6 × 0 = 0
• Constant: 6.4
• Total MELD ≈ 15 1, 2

Critical Clinical Context

Prognostic Significance

• MELD ≥15 is the recommended threshold for liver transplant listing, as patients with MELD ≤14 have better 1-year survival without transplantation than with it 1, 2
• This patient's MELD score of approximately 15 indicates 20-30% three-month mortality risk without transplantation 1, 3
• The elevated bilirubin of 7 mg/dL is the primary driver of this patient's MELD score and reflects significant hepatocellular dysfunction 1

Immediate Management Actions Required

Transplant Evaluation:

• Refer immediately for liver transplantation evaluation given MELD ≥15 1, 2
• Engage multidisciplinary transplant team for comprehensive assessment 2

Monitoring Protocol:

• Recalculate MELD score every 1-2 weeks to track disease trajectory 2
• Monitor for acute decompensation events (ascites, encephalopathy, variceal bleeding, spontaneous bacterial peritonitis, hepatorenal syndrome) 1
• Serial assessment of renal function, as creatinine elevation would significantly increase MELD score 1, 2

Complication Surveillance:

• Screen for hepatocellular carcinoma, which may warrant MELD exception points 1, 2
• Assess for portal hypertension complications including varices and ascites 1
• Monitor for hepatic encephalopathy development 1

Important Caveats and Pitfalls

Laboratory Variability Issues

INR Measurement Concerns:

• The INR component shows the greatest interlaboratory variability in MELD calculation, with differences of 2-12 MELD points possible between laboratories 4
• Different thromboplastin reagents can yield substantially different INR values for the same sample 5, 4
• The INR was designed for monitoring warfarin therapy, not for assessing liver disease coagulopathy, and may not accurately reflect true bleeding risk in cirrhosis 1, 6

PT Ratio vs INR:

• Your patient's PT ratio of 1.096 is relatively modest, suggesting early-stage coagulopathy 1
• In liver disease, PT ratio may be more reliable than INR for assessing coagulation status 6

Clinical Limitations of MELD

MELD Does Not Capture:

• Presence of ascites, encephalopathy, or variceal bleeding—all of which significantly worsen prognosis 1
• Nutritional status, sarcopenia, or frailty 2
• Hepatocellular carcinoma burden 1, 2
• Hepatopulmonary syndrome or portopulmonary hypertension 1, 2

Creatinine Reliability:

• Serum creatinine can overestimate renal dysfunction in sarcopenic patients and underestimate it in fluid-overloaded patients 2
• Patients on dialysis receive a maximum creatinine value of 4.0 mg/dL in MELD calculation 2

Child-Pugh Score Comparison

For comprehensive assessment, also calculate Child-Pugh score using:

• Bilirubin 7 mg/dL = 3 points
• PT 1.7 seconds prolonged (13.7-12.0) = 1 point
• Plus albumin, ascites, and encephalopathy status 1

Child-Pugh classification remains an independent prognostic factor and should be used alongside MELD for complete risk stratification 3

Common Errors to Avoid

• Do not delay transplant referral while awaiting further clinical deterioration; MELD ≥15 mandates immediate evaluation 1, 2
• Do not use MELD as the sole criterion if patient has hepatocellular carcinoma or other conditions warranting exception points 1, 2
• Do not ignore clinical decompensation (ascites, encephalopathy, variceal bleeding) even if MELD score appears "borderline" 1, 2
• Do not transfuse plasma to "correct" the INR in non-bleeding patients, as this provides no clinical benefit and the INR serves as a prognostic marker 6, 7