24, 28
The apnoea test is attempted in only half of ECMO patients assessed for brain death and fails about one time in five when attempted - but a single centre with a written technique completed it in all 25 of its ECMO patients without a severe complication. The variable is the protocol, not the patient.
Completion and confirmation of the determination
DOI 10.1016/j.jtcvs.2020.03.038
Apnoea testing on a circuit, by any method, plus ancillary testing
Pooled heterogeneous case reports and small series with widely varying and often unreported technique. Structured abstract only. [VERIFICATION REQUIRED]
Only 88 patients (50%) underwent an apnoea test. Method most often decreasing sweep flow (14 studies, n = 42, 48%), then carbon dioxide via the ventilator (n = 6, 7%) or the oxygenator (n = 1, 1%); method unreported for 39 (44%). The test was non-confirmatory in 19 of 88 (22%) because of haemodynamic instability, hypoxia, insufficient carbon dioxide rise or unreliability. 157 ancillary tests were performed (EEG 62%, CT angiography 22%, transcranial Doppler 6%, nuclear cerebral blood flow 5%, cerebral angiography 4%). 47 patients (53% of those with a confirmatory apnoea test) had ancillary testing anyway, and only 21 patients (12% of the cohort) were declared on a confirmatory apnoea test alone.
22 studies, 177 adults assessed for brain death while on ECMO