How is Liver Transplantation Need Determined?

There are a number of "scoring systems" or "scales" used for determining a patient's need for a liver transplant. Two of the most common are known as MELD and PELD. A number value is assigned to the patient's condition, and that number which reflects the urgency of the patient's need for a liver transplant. Doctors assign the number based on lab tests and other diagnostic tools. They also take into account any other health problems the patient may be experiencing.

MELD MELD stands for Model for End-Stage Liver Disease. The MELD system rates the patient's risk of death within 3 months if the patient doesn't get a liver transplant. It's used for adult liver candidates who are age 18 or older. The number will be between 6 and 40, and the higher it is, the more urgent the need. The score may fluctuate while the patient is waiting for a donor, depending on factors related to the health of their liver as evaluated by their medical team.

PELD The Pediatric End-Stage Liver Disease, or PELD scale, has a similar 6-40 point scale. PELD scoring rates the risk or probability of death within 3 months. The PELD score takes growth parameters into account along with laboratory and clinical values.

In both MELD and PELD, the length of time a patient has been on the waiting list becomes a factor in determining the number. A patient who has been on the list longest will get a transplant soonest. This assumes, of course, that other factors are equal and there's a matching blood type.

In early 2002, the United Network for Organ Sharing (UNOS) modified the way need for a liver transplant was assigned. Before 2002, patients were ranked as status 1, 2A, 2B, and 3. The status 1 listing has remained, but all other patients are now classified using MELD or PELD scoring systems, depending on age.

Status 1 is considered extremely urgent, and it supersedes the MELD and PELD scores. Someone with's classified as status 1 is considered to have complete liver failure and would probably die within seven days without a liver transplant.

When a liver becomes available from a donor, it is available first to status 1 patients in the local area first, followed by patients with the highest MELD or PELD scores. If there are no local match, the liver would then be offered regionally (again using MELD and PELD values), and finally, on a national level.