Complications associated with the apnea test in the determination of the brain death

Background An apnea test is essential in the clinical determination of brain death. This study was conducted to analyse complications associated with the apnea test in the determination of the brain death. Methods On 93 adult patients in coma in Zhejiang Province of China from January 2003 to December 2006,179 apnea tests were performed as a part of the determination of brain death. Potential risk conditions and complications were analysed during apnea tests. Results During apnea, serious cardiac arrhythmia did not occur in all patients. Complications occurred in 37 of 179 (21%) apnea tests. Hypotension occurred in 30 patients (17%) and it was observed in 8/94 (9%) tests with baseline value of systolic arterial blood pressure not less than 120 mmHg, and 22/85 (26%) less than 120 mmHg (P<0.05). Severe hypoxaemia occurred in 10 patients (6%) of which 3/138 (2%) tests with baseline value of arterial oxygen pressure not less than 200 mmHg, and 7/41 (17%) less than 200 mmHg (P<0.05). Conclusions This study demonstrated that complications occurred mostly in patients with inadequate baseline systolic arterial blood pressure and preoxygenation. Adequate precautions during the apnea tests may reduce the risk of cardiovascular and oxygenation complication.