Prediction of Apnea Testing Duration to Ensure Safety During Brain Death Assessment

Abstract

BACKGROUND: Apnea testing is the last step of brain death assessment. This study aimed to determine whether apnea testing is safer when performed over a shorter duration. METHODS: The medical records of 200 brain-dead donors were retrospectively evaluated. All the records were anonymously registered in the Japanese Ministry of Health, Labor, and Welfare from 1999 to 2012. The rate of P aCO 2 increase was analyzed to calculate the duration required for apnea testing. RESULTS: At baseline, body temperature and P aO 2 significantly affected the increase rate of P aCO 2 . At baseline, the apnea testing durations were 4.7 min with normal body temperature and higher P aO 2 (P aCO 2 40-60 mm Hg, body temperature 36.5 C, P aO 2 400 mm Hg); further, it was 3.0 min with higher body temperature and lower P aO 2 at baseline (P aCO 2 40-60 mm Hg, body temperature 38.0 C, P aO 2 100 mm Hg). CONCLUSIONS: The specific duration of apnea testing during brain death assessment may be predicted by measuring the increase rate of P aCO 2 .