Problems associated with the apnea test in the diagnosis of brain death.

Background: Brain death is the absence of all cortical functions, including the brainstem. The apnea test (AT) is a necessary requisite to complete this diagnosis. Anecdotal reports describing hypotension and acidosis due to apnea test have been reported. However, there are few studies that evaluate complications or difficulties related to this procedure.

Objective: To analyze medical problems associated with the apnea test.

Methods And Patients: We analyzed clinical features, potential risk conditions, and problems in 129 brain dead patients during the apnea test. The diagnosis of brain death was made according to the American Academy of Neurology recommendations.

Results: Clinical problems during the apnea test were detected in more than two thirds of patients, including: arterial hypotension (12%), acidosis (68%), and hypoxemia (23%). Four patients developed major complications, including: pneumothorax, cardiac arrest, bradycardia, atrial fibrillation and myocardial infarction.

Conclusion: The apnea test is not an innocuous procedure. Complications during the AT are more common than reported and limit organ procurement for transplantation. Guidelines for performing the AT should be followed in order to avoid clinical complications.