Model for End-Stage Liver Disease
Encyclopedia
The Model for End-Stage Liver Disease, or MELD, is a scoring system for assessing the severity of chronic liver disease
. It was initially developed to predict death within three months of surgery in patients who had undergone a transjugular intrahepatic portosystemic shunt
(TIPS) procedure, and was subsequently found to be useful in determining prognosis and prioritizing for receipt of a liver transplant. This score is now used by the United Network for Organ Sharing
(UNOS) and Eurotransplant
for prioritizing allocation of liver transplants
instead of the older Child-Pugh score
.
, serum creatinine
, and the international normalized ratio for prothrombin time (INR)
to predict survival. It is calculated according to the following formula:
UNOS has made the following modifications to the score:
Patients with a diagnosis of liver cancer will be assigned a MELD score based on how advanced the cancer is.
, and at that point was called the "Mayo End-stage Liver Disease" score. It was derived in a series of patients undergoing TIPS procedures. The original version also included a variable based on the underlying etiology (cause) of the liver disease. The score turned out to be predictive of prognosis in chronic liver disease in general, and–with some modifications–came to be applied as an objective tool in assigning need for a liver transplant. The etiology turned out to be relatively unimportant, and was also regarded as relatively subjective; it was therefore removed from the score.
Chronic liver disease
Chronic liver disease in the clinical context is a disease process of the liver that involves a process of progressive destruction and regeneration of the liver parenchyma leading to fibrosis and cirrhosis.- Causes :...
. It was initially developed to predict death within three months of surgery in patients who had undergone a transjugular intrahepatic portosystemic shunt
Transjugular intrahepatic portosystemic shunt
A Transjugular Intrahepatic Portosystemic Shunt is an artificial channel within the liver that establishes communication between the inflow portal vein and the outflow hepatic vein...
(TIPS) procedure, and was subsequently found to be useful in determining prognosis and prioritizing for receipt of a liver transplant. This score is now used by the United Network for Organ Sharing
United Network for Organ Sharing
Located in Richmond, Virginia, the United Network for Organ Sharing is a non-profit, scientific and educational organization that administers the only Organ Procurement and Transplantation Network in the United States, established by the U.S. Congress in 1984.UNOS was awarded the initial OPTN...
(UNOS) and Eurotransplant
Eurotransplant
The Eurotransplant International Foundation, commonly known simply as Eurotransplant, is an international non-profit organization responsible for encouraging and coordinating organ transplants in its member countries. The headquarters of Eurotransplant are located in Leiden, the Netherlands. The...
for prioritizing allocation of liver transplants
Liver transplantation
Liver transplantation or hepatic transplantation is the replacement of a diseased liver with a healthy liver allograft. The most commonly used technique is orthotopic transplantation, in which the native liver is removed and replaced by the donor organ in the same anatomic location as the original...
instead of the older Child-Pugh score
Child-Pugh score
In medicine , the Child-Pugh score is used to assess the prognosis of chronic liver disease, mainly cirrhosis...
.
Determination
MELD uses the patient's values for serum bilirubinBilirubin
Bilirubin is the yellow breakdown product of normal heme catabolism. Heme is found in hemoglobin, a principal component of red blood cells. Bilirubin is excreted in bile and urine, and elevated levels may indicate certain diseases...
, serum creatinine
Creatinine
Creatinine is a break-down product of creatine phosphate in muscle, and is usually produced at a fairly constant rate by the body...
, and the international normalized ratio for prothrombin time (INR)
Prothrombin time
The prothrombin time and its derived measures of prothrombin ratio and international normalized ratio are measures of the extrinsic pathway of coagulation. This test is also called "ProTime INR" and "INR PT". They are used to determine the clotting tendency of blood, in the measure of warfarin...
to predict survival. It is calculated according to the following formula:
- MELD = 3.78[Ln serum bilirubin (mg/dL)] + 11.2[Ln INR] + 9.57[Ln serum creatinine (mg/dL)] + 6.43
UNOS has made the following modifications to the score:
- If the patient has been dialyzedDialysisIn medicine, dialysis is a process for removing waste and excess water from the blood, and is primarily used to provide an artificial replacement for lost kidney function in people with renal failure...
twice within the last 7 days, then the value for serum creatinine used should be 4.0 - Any value less than one is given a value of 1 (i.e. if bilirubin is 0.8, a value of 1.0 is used) to prevent the occurrence of scores below 0 (the natural logarithmNatural logarithmThe natural logarithm is the logarithm to the base e, where e is an irrational and transcendental constant approximately equal to 2.718281828...
of 1 is 0, and any value below 1 would yield a negative result)
Patients with a diagnosis of liver cancer will be assigned a MELD score based on how advanced the cancer is.
Interpretation
In interpreting the MELD Score in hospitalized patients, the 3 month mortality is:- 40 or more — 71.3% mortality
- 30–39 — 52.6% mortality
- 20–29 — 19.6% mortality
- 10–19 — 6.0% mortality
- <9 — 1.9% mortality
History
MELD was originally developed at the Mayo ClinicMayo Clinic
Mayo Clinic is a not-for-profit medical practice and medical research group specializing in treating difficult patients . Patients are referred to Mayo Clinic from across the U.S. and the world, and it is known for innovative and effective treatments. Mayo Clinic is known for being at the top of...
, and at that point was called the "Mayo End-stage Liver Disease" score. It was derived in a series of patients undergoing TIPS procedures. The original version also included a variable based on the underlying etiology (cause) of the liver disease. The score turned out to be predictive of prognosis in chronic liver disease in general, and–with some modifications–came to be applied as an objective tool in assigning need for a liver transplant. The etiology turned out to be relatively unimportant, and was also regarded as relatively subjective; it was therefore removed from the score.