Difficulties in assessing brain death in a case of benzodiazepine poisoning with persistent cerebral blood flow.

Assessing brain death may sometimes be difficult, with isoelectric EEG following psychotrope overdoses or normal cerebral blood flow (CBF) persisting despite brain death in the case of ventricular drainage or craniotomy. A 42-year-old man, resuscitated after cardiac arrest following a suicidal ingestion of ethanol, bromazepam and zopiclone, was admitted in deep coma. On day 4, his brainstem reflexes and EEG activity disappeared. On day 5, his serum bromazepam concentration was 817 ng/ml (therapeutic: 80-150). The patient was unresponsive to 1 mg of flumazenil. MRI showed diffuse cerebral swelling. CBF assessed by angiography and Doppler remained normal and EEG isoelectric until he died on day 8 with multiorgan failure. There was a discrepancy between the clinically and EEG-assessed brain death, and CBF persistence. We hypothesized that brain death, resulting from diffuse anoxic injury, may lead, in the absence of major intracranial hypertension, to angiographic misdiagnoses. Therefore, EEG remains useful to assess diagnosis in such unusual cases.

Predicting survival with good neurological recovery at hospital admission after successful resuscitation of out-of-hospital cardiac arrest: the OHCA score.

AIMS: Out-of-hospital cardiac arrest (OHCA) is common and carries a bleak prognosis. Early prediction of unfavourable outcomes is difficult but crucial to improve resource allocation. The aim of this study was to develop a simple tool for predicting survival with good neurological function in the overall population of patients with successfully resuscitated cardiac arrest. METHODS AND RESULTS: We used logistic regression analysis to identify clinical and laboratory variables that were both readily available at admission and predictive of poor outcomes (death or severe neurological impairment) in a development cohort of 130 consecutive OHCA patients admitted to a French intensive care unit (ICU) between 1999 and 2003. To test the prediction score built from these variables, we used a validation cohort of 210 patients recruited in four French ICUs between 2003 and 2005. Initial rhythm, estimated no-flow and low-flow intervals, blood lactate, and creatinine levels determined using whole blood analyzers were independently associated with poor outcomes and were used to build a continuous severity score. Goodness-of-fit tests indicated good performance (P=0.79 in the development cohort and P=0.13 in the validation cohort). The area under the receiver-operating characteristics curve was 0.82 in the development cohort and 0.88 in the validation cohort. CONCLUSION: The outcome can be accurately predicted after OHCA using variables that are readily available at ICU admission.