The MELD score (Model for End-stage Liver Disease) is a classification used to grade liver dysfunction in preparation for liver transplantation. It is an estimate of 3 month mortality.
The components of the score are:
- serum creatinine (mg/dl)
- if dialysis twice in last week, then bilirubin is given a value of 4 mg/dl
- total bilirubin (mg/dl)
These variables are used to calculate the score 2:
MELD = (0.957 x ln [Cr]) + (0.378 x ln [bilirubin]) + (1.120 x ln [INR]) + 0.643
(ln = log to the base of e, loge)
Scores are used to prioritize liver transplantation:
- >15: may benefit from liver transplantation
Certain clinical situations lead to automatic increases in the MELD score in an attempt to increase or decrease waiting times on a liver transplant waiting list:
- hepatocellular carcinoma: +22 points
- hepatopulmonary syndrome
- familial amyloidosis
- primary oxaluria (pediatric patients)
Use of the MELD score to prioritize transplants has lead to a decreased rate of pretransplant death for those on the waiting list, but use of the score causes some controversy because it does not indicate survival benefit of transplantation.
Patients with acute liver failure are given a distinction called "status 1," which supersedes MELD scores in terms of transplantation prioritization.
The PELD score is used for patients younger than 12 years of age.