Benefit of a single recruitment maneuver after an apnea test for the diagnosis of brain death

Abstract

IntroductionMany potential lung transplants are lost because of hypoxemia during donor management. We hypothesized that the apnea test, necessary to confirm the diagnosis of brain death in potential lung donors, was involved in the decrease in the ratio of partial pressure of arterial O2 to fraction of inspired O2 (PaO2/FiO2) and that a single recruitment maneuver performed just after the apnea test can reverse this alteration.MethodsIn this case-control study, we examined the effectiveness of the recruitment maneuver with a comparison cohort of brain dead patients who did not receive the maneuver. Patients were matched one-to-one on the basis of initial PaO2/FiO2 and on the duration of mechanical ventilation before the apnea test. PaO2/FiO2 was measured before (T1), at the end (T2) and two hours after apnea test (T3).ResultsTwenty-seven patients were included in each group. The apnea test was associated with a significant decrease in PaO2/FiO2 from 284 ± 98 to 224 ± 104 mmHg (P < 0.001). The decrease in PaO2/FiO2 between T1 and T3 was significantly lower in the recruitment maneuver group than in the control group (-4 (-68-57) vs -61 (-110--18) mmHg, P = 0.02). The number of potential donors with PaO2/FiO2 > 300 mmHg decreased by 58% (95% CI: 28-85%) in the control group vs 0% (95% CI: 0-34%) in the recruitment maneuver group (P < 0.001).ConclusionsThe apnea test induced a decrease in PaO2/FiO2 in potential lung donors. A single recruitment maneuver performed immediately after the apnea test can reverse this alteration and may prevent the loss of potential lung donors.

Where are We on Organ Donation?

“…In our study blood gas analyses before and after apnea test suggests that apneic oxygenation method is reliable in the presence of appropriate pre-oxygenation. However Paries et al (14) showed that apnea test damages respiratory functions and suggested that lungsaving strategies, especially recruitment maneuvers should be routinely used after the test. An article about criteria for selection of receiver-donor for heart transplantation reported that 20-25% of organs, which are very hardly obtained indeed, were lost due to insufficient treatment of physiopathological responses occurred after brain death (15).…”

Recruitment maneuver after apnea test or continuous positive airway pressure apnea test?

“…We wish to remind that the aim of our study [1] was not to compare the PaO 2 /FiO 2 ratio after apnea tests performed by disconnecting or not the patient from the ventilator. It was to show that hypoxemia after disconnection from the ventilator may be prevented by a single RM applied just after reconnection.…”

“…We read with interest the study by Marie Paries and collaborators [1]. Many potential lung transplants are lost because of hypoxemia after apnea test.…”

Novel method of delivery of continuous positive airway pressure for apnea testing during brain death evaluation

“…For those patients who go on to become organ donors, atelectasis and higher pressures necessary to recruit the collapsed alveoli induced by apnea testing can cause significant injury and potentially decrease lung recovery rates. 7 The objective measure of lung quality used by most transplant surgeons is the P:F ratio, the ratio of the partial pressure of arterial oxygen (PaO 2 ) to fraction of inspired oxygen (FiO 2 ). The P:F ratio has been found to be significantly associated with organ recipient prognosis 8 and most transplant surgeons require a P:F ratio of >300 on a positive end expiratory pressure (PEEP) of 5 for eligibility.…”