On such a view, NHBD
protocols might have more in common with "conscience clauses" than is generally recognized.
Machine preservation using continuous hypothermic pulsatile perfusion has been adopted in NHBD kidney screening initiatives, and perfusion characteristics (flow, pressure, resistance, temperature, weight gain) with enzyme analysis of kidney effluents are used to assess viability.
Original work by the Maastricht NHBD group has established threshold limits for tGST activity in kidney perfusates for the selection of "viable" kidneys for transplantation (6).
Most guidelines describe a potential NHBD as a patient who has suffered a severe head injury, does not meet brain-death criteria, is dependent on a ventilator and is between 5 and 55 years of age.
An uncontrolled NHBD is one in which the time and location of death are not predictable, such as a cardiac arrest in the emergency room.
The above NHBD procedures are now routinely followed despite the fact that there is no scientific evidence that proves how long after the last heartbeat the heart will no longer be able to start beating again and restore circulation.
11) That NHBD supporters define death in inconsistent and non-objective terms is demonstrated in a 1999 study of 108 patients.
Michael Cecka, PhD from the University of California, Los Angeles conservatively estimated that transplantation from NHBD
would represent up to 1,000 more kidneys available for transplant in the United States each year.
26] Many in the transplant field see NHBDs as a key source to meet the growing demand for organs, and many other NHBD protocols have been proposed.
One was that the drugs administered prior to death in NHBD protocols--anticoagulants (heparin) and vasodilators (regitine) to minimize the effects of warm ischemia on organ viability--could hasten or even cause death.
One of the more controversial topics the IOM faced was the timing of death in controlled NHBD protocols.
Two aspects of the legal criteria for death are relevant to the controlled NHBD protocols and the five-minute rule.