HEMODYNAMIC-CHANGES DURING THE APNEA TEST IN PATIENTS WITH BRAIN-DEATH

Objective: in France, an apnoea test is compulsory to confirm brain de ath. This test results in a major hypercarbia and respiratory acidosis . This study aimed to assess haemodynamic changes elicited by the apno ea test. Study design: Prospective clinical study. Patients: Fifteen p atients with brain death. Methods: Before the apnoea test, the lungs w ere ventilated with pure oxygen for 20 minutes. Thereafter, the test w as conducted with continuous oxygen flow through the endotracheal tube , and SpO(2) monitoring. Blood gases and haemodynamic parameters, incl uding systemic arterial pressure, pulmonary artery pressure, pulmonary artery occlusion pressure, cardiac index and right Ventricular functi on parameters were assessed before, during and 20 minutes after the ap noea test. Mean Values at the Various times were compared. Results: Hy percarbia and acidosis induced a major pulmonary hypertension and an i ncrease in cardiac output, associated with a decrease in systemic vasc ular resistances. Despite pulmonary hypertension and acidosis, right v entricular function was maintained. All haemodynamic modifications wer e reversed by reventilation. Conclusion: Apnoea test induces a reversi ble pulmonary hypertension that is seemingly not deleterious for right ventricular function. Apnoea test probably does not alter viability o f the donor's organs.