Model for End-Stage Liver Disease
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 mortality within three months of surgery in patients who had undergone a transjugular intrahepatic portosystemic shunt (TIPS) procedure,[1] and was subsequently found to be useful in determining prognosis and prioritizing for receipt of a liver transplant.[2][3] 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.[3][4]
Determination
MELD uses the patient's values for serum bilirubin, serum creatinine, and the international normalized ratio for prothrombin time (INR) to predict survival. It is calculated according to the following formula:[3]
- MELD = 3.78×ln[serum bilirubin (mg/dL)] + 11.2×ln[INR] + 9.57×ln[serum creatinine (mg/dL)] + 6.43
MELD scores are reported as whole numbers, so the result of the equation above is rounded.
UNOS has made the following modifications to the score:[5]
- If the patient has been dialyzed twice within the last 7 days, then the factor 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 (because any positive value below 1 the natural logarithm would yield a negative result)
The etiology of liver disease was subsequently removed from the model because it posed difficulties such as how to categorize patients with multiple causes of liver disease. Modification of the MELD score by excluding etiology of liver disease did not significantly affect the model's accuracy in predicting three-month survival.
Patients with a diagnosis of liver cancer will be assigned a MELD score based on how advanced the cancer is. [citation needed]
Interpretation
In interpreting the MELD Score in hospitalized patients, the 3 month mortality is:[6]
- 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 Clinic by Dr. Patrick Kamath, 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.[1] 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.[3]
See also
References
- ^ a b Malinchoc M, Kamath PS, Gordon FD, Peine CJ, Rank J, ter Borg PC (April 2000). "A model to predict poor survival in patients undergoing transjugular intrahepatic portosystemic shunts". Hepatology. 31 (4): 864–71. doi:10.1053/he.2000.5852. PMID 10733541.
- ^ Kamath PS, Wiesner RH, Malinchoc M, Kremers W, Therneau TM, Kosberg CL, D'Amico G, Dickson ER, Kim WR (2001). "A model to predict survival in patients with end-stage liver disease". Hepatology. 33 (2): 464–70. doi:10.1053/jhep.2001.22172. PMID 11172350.
- ^ a b c d Kamath PS, Kim WR (March 2007). "The model for end-stage liver disease (MELD)". Hepatology. 45 (3): 797–805. doi:10.1002/hep.21563. PMID 17326206.
- ^ Jung GE, Encke J, Schmidt J, Rahmel A (February 2008). "Model for end-stage liver disease. New basis of allocation for liver transplantations". Chirurg (in German). 79 (2): 157–63. doi:10.1007/s00104-008-1463-4. PMID 18214398.
- ^ UNOS (2009-01-28). "MELD/PELD calculator documentation" (PDF). Retrieved 2010-02-21.
- ^ Wiesner et al. Model for end-stage liver disease (MELD) and allocation of donor livers. Gastroenterology (2003) vol. 124 (1) pp. 91-6. PMID 12512033