Apnea testing is a safety check, not a box to rush through. Abort it for instability, and only call it positive when the physiologic threshold and absent respiratory effort both line up.

For adults, a single completed apnea test combined with matching clinical criteria is legally sufficient; It must be repeated if the individual is under 18 years old; 2025 study highlighted that a second, follow-up transcranial Doppler study provided 100% confirmation of the initial study's findings during brain death evaluations, strongly reinforcing its diagnostic reliability; Life-sustaining measures are formally withdrawn directly inside the operating room; Once circulatory arrest occurs, an independent physician declares death, and the individual must be observed for at least a full two minutes before organ procurement can begin