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Discontinuation of ventilation after brain stem death

Editor—We were interested in the educational debate concerning withdrawal of ventilatory support after confirmation of brain stem death.1 Clearly if ventilatory support is withdrawn without the agreement of the family, although such action may be medically and legally correct, the potential for sensationalised unfavourable headings in tabloid newspapers must be considered. 
 
Although the medicolegal and ethical aspects of the issue have been discussed, the scientific aspects have not been. Unlike in the persistent vegetative state, brain stem death is followed by a series of profound changes in the autonomic and hormonal mechanisms regulating the cardiovascular system. Complete cardiovascular and autonomic uncoupling has been shown in humans after brain stem death.2 In validated animal models of brain stem death a catecholamine surge was consistently observed after brain stem death, followed rapidly by decreases in vasopressin, adrenocorticotrophic hormone, thyroxine, and glucagon concentrations.3 Inotropic and vasoactive treatment is therefore frequently required to maintain organ function for potential donation. 
 
It has been established that, despite full cardiovascular support, most deeply comatose patients (97% of 140) will develop asystole in a week.4 Clearly, the time for developing asystole is likely to be shorter in patients with brain stem death, especially if full cardiovascular support is not attempted. We suggest that in such cases it would be reasonable to continue ventilatory and circulatory support without further manipulation. In almost all cases managed in this way rapid cardiac death will ensue. 
 
Although we have no satisfactory answer to the central question raised as to whom the duty of care is greatest—the grieving family or another critically ill patient—we believe that nature should be allowed to take its own course and end the dilemma.