Ethical considerations in the allocation of organs and other scarce medical resources among patients. Council on Ethical and Judicial Affairs, American Medical Association

Physicians' efforts on behalf of patients often involve the use of resources that, because of naturally limited supply or economic constraints, are not readily available to all who need them. The dilemma in such cases is how physicians may fulfill their ethical duties to "do all that [they] can for the benefit of the individual patient" when the care that they can provide is constrained by the scarcity of needed resources.

Published by Archives of internal medicine, 1995. The guideline itself is at the source linked here.

pubmed.ncbi.nlm.nih.gov/7802518/