MELD Na (UNOS/OPTN)

MELD-Na (UNOS/OPTN)

Bilirubin

mg/dL

Creatinine

mg/dL

INR

Sodium

mEq/L

Dialysis (at least twice in the past week)

Quantifies end-stage liver disease for transplant planning with sodium.

Why Use

In February 2002, MELD was accepted by the United Network for Organ Sharing (UNOS) for prioritization of patients awaiting for liver transplantation in the United States, replacing the Child-Pugh Score . It has been widely studied and validated.

When to Use

Primarily used to stratify patients ≥12 years old on liver transplant waiting lists. Predicts mortality in the following scenarios: (a) after transjugular intrahepatic portosystemic shunt (TIPS), (b) cirrhotic patients undergoing non-transplantation surgical procedures, (c) acute alcoholic hepatitis, and (d) acute variceal hemorrhage.

Formula

Per OPTN policy, January 2016 (pages 4–5) : Candidates who are at least 12 years old receive an initial MELD(i) score equal to: MELD(i) = 0.957 × ln(Cr) + 0.378 × ln(bilirubin) + 1.120 × ln(INR) + 0.643 Then, round to the tenth decimal place and multiply by 10. If MELD(i) > 11, perform additional MELD calculation as follows: MELD = MELD(i) + 1.32 × (137 – Na) – [ 0.033 × MELD(i) × (137 – Na) ] Additional rules: All values in US units (Cr and bilirubin in mg/dL, Na in mEq/L, and INR unitless). If bilirubin, Cr, or INR is <1.0, use 1.0. If any of the following is true, use Cr 4.0: Cr >4.0. ≥2 dialysis treatments within the prior 7 days. 24 hours of continuous veno-venous hemodialysis (CVVHD) within the prior 7 days. If Na <125 mmol/L, use 125. If Na >137 mmol/L, use 137. Maximum MELD = 40.

Pearls / Pitfalls

The MELD Score predicts three-month survival in patients (age 12+) with liver cirrhosis. Scores range from 6 to 40, with higher scores correlating with increased severity of liver dysfunction and higher three-month mortality. The MELD was updated in January 2016 and now includes serum sodium level. It is preferable to using the calculator to calculate the MELD as there are several caveats relating to minimum and maximum values assigned in the MELD. Values should be no more than 48 hours old. MELD can be used on any patient with end stage liver disease irrespective of cirrhosis etiology. Currently, there is no modification in the score for patients on anticoagulation (given their INR may be elevated). Several conditions are “standard MELD exceptions” and receive a different score (see Next Steps > Critical Actions ): hepatocellular carcinoma, hepatopulmonary syndrome, portopulmonary hypertension, familial amyloid polyneuropathy, primary hyperoxaluria, cystic fibrosis, hilar cholangiocarcinoma and hepatic artery thrombosis. One of the exclusion criteria for the original data set was absence of acute reversible conditions such as spontaneous bacterial peritonitis or prerenal azotemia secondary to dehydration. Therefore, in principle, the score should only be applied after these reversible conditions have been treated, according to the authors ( Kamath 2007 ).

Critical Actions

Standard MELD Exceptions The following conditions are automatically assigned a MELD Score of 22 (28 in case of hyperoxaluria), with a 10% increase in score every 3 months from diagnosis. Hepatocellular carcinoma (HCC) with one lesion between 2 - 5 cm or two to three lesions <3 cm (Milan criteria), provided no vascular invasion or extrahepatic disease. Hepatopulmonary syndrome with PaO 2 <60 mmHg on room air. Portopulmonary hypertension, with mean pulmonary artery pressure (mPAP) >25 mmHg at rest but maintained <35 mmHg with treatment. Hepatic artery thrombosis 7–14 days post-liver transplantation. Familial amyloid polyneuropathy, as diagnosed by identification of the transthyretin (TTR) gene mutation by DNA analysis or mass spectrometry in a biopsy sample and confirmation of amyloid deposition in an involved organ. Primary hyperoxaluria with evidence of alanine glyoxylate aminotransferase deficiency (these patients requires combined liver-kidney transplantation). Cystic fibrosis with FEV1 (forced expiratory volume in 1 second) <40%. Hilar cholangiocarcinoma.

Advice

Consider referral to hepatologist or liver transplant center for patients with MELD Score ≥10. MELD Score should be periodically re-assessed, as it changes with changing lab values. All cirrhosis patients should be periodically screened for hepatocellular carcinoma with serum alpha-fetoprotein (AFP) and by appropriate imaging to see if they can earn “standard MELD exceptions”.

More Information

Interpretation: MELD Score Mortality ≤9 1.9% 10–19 6.0% 20–29 19.6% 30–39 52.6% ≥40 71.3% More Info: OPTN/UNOS Documentation on MELD and PELD