Through the Organ Procurement Transplant Network (OPTN) and the United Network for Organ Sharing (UNOS), the transplant community has developed a new organ allocation system for lung patients awaiting transplantation, effective April 2005. The system was designed to more effectively use the limited number of available donor lungs among transplant candidates in order to reduce the number of deaths on the waiting list. As with changes that have occurred in heart and liver allocation, UNOS has moved away from using waiting time and has moved toward using need to prioritize patients on the national lung waiting list. |
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Under the new system, each lung patient over the age of twelve will receive a "lung allocation score," ranging from 0 (less ill) to 100 (gravely ill). Patients with higher scores will receive priority over those with lower scores. The score will be updated every six months based on regularly scheduled testing. The score can also be reassessed by additional testing at any point if a patient’s clinical status changes.
The Transplant Team has been discussing the upcoming change with lung patients as UNOS’ plans have evolved. In addition, the team has a data collection system to ensure that patients’ lung allocation scores are updated as soon as they complete their required six month testing. The transplant center may update testing or diagnostic information on the system at any time to reflect a change in a candidate’s disease severity. A Lung Review Board will review those candidates that the team considers to have an exceptional case.
The lung score will be computed based on a variety of clinical factors (described below).
Forced vital capacity This is a lung function test that measures the maximum amount of air you can breathe out after you breathe in as deeply as possible. Pulmonary artery pressure This is the pressure the heart must generate to pump blood through the lungs. This pressure may be high in some patients with serious lung disease. Oxygen at rest This is the amount of oxygen needed by a patient at rest to maintain adequate oxygen levels in the blood. Patients with severe lung disease may need additional oxygen. Age This is the candidate’s age at the time lungs are offered. Body mass index BMI is a ratio of a patient’s weight to height that, when interpreted with other medical test results, helps to evaluate health status. Insulin dependent diabetes Diabetes may be a predictor of health status in some patients with lung disease. Functional status The New York Heart Association classifications measure effects that lung disease may have on a patient’s function in everyday life. Creatinine Creatinine levels are a measure of kidney function. 6-Minute walk distance In the 6-minute walk test, a patient is asked to walk as far as s/he can in 6 minutes. The distance walked is a measure of functional status. Ventilator use The use of a ventilator to assist breathing may be a measure of disease severity and may affect success after transplant. Pulmonary capillary wedge pressure PCW or "Wedge Pressure" is the pressure blood returning to the heart from the lungs must overcome. This pressure can become increased when the heart is not pumping effectively. Diagnosis Research has shown that urgency among patients needing a transplant and success after transplant vary among patients with different lung diseases due to the specific progression of the particular disease. Therefore, for every patient, diagnosis factors into the calculation of the lung allocation score. Source: UNOS brochure, "Questions and Answers About the Change in the Lung Allocation Policy." You can access the full brochure by visiting the "What’s New" area of the CTC’s website: |
The clinical factors that make up the basis of the lung allocation score measure candidates’ medical urgency prior to transplant and thier probability of success following a transplant, their transplant benefit. Those expected to receive the greatest transplant benefit will receive priority for lung offers.
How must patients prepare for the new system? "Because we have to update the lung allocation score a minimum of every six months, it is important now,
more than ever, that there not be delays in obtaining testing or keeping clinic appointments. Also, patients will need to inform their transplant team of changes in their medical condition which may affect their scoring or need for additional testing," says Terri Cook, Transplant Coordinator.
If you are a lung patient and have questions or need more information, contact your transplant coordinator, 410-614-4898.
- Terri Cook, R.N., B.S.N. and Jonathan Orens, M.D. contributed to this article.
