Evaluation of the Clinical and Electrophysiological Responses of the Brainstem in Patients With Alteration of Consciousness in Relation or Not With Sedation: Prognostic Study of Brain Reflexes

Severe diseases in intensive care unit (ICU) patients are associated with a high mortality rate which nevertheless remains difficult to predict. Recently, the abolition of some brainstem reflexes at clinical examination of ICU patients within the first 24 hours after has been shown of prognostic value in ICU patients requiring sedation. Early abolition of the cough reflex was associated with an increase in mortality and that of the oculocephalic reflex was predictive of coma or delirium after sedation has been stopped. A dysfunction of the brainstem may account for these results and be present in other patient subpopulations, particularly those who do not receive iv sedation or the brain injured patients, who were eluded from the previous study. This dysfunction could take place in the muti-organ failure characteristic of the severe ICU patient. On the other hand, a preliminary study performed on somatosensory evoked potentials has shown that a latency of the P14 wave greater than 16 ms between day 1 and day 3 after admission was associated with death at 28 days. The primary goal of this project is to confirm this hypothesis. By studying the clinical and electrophysiological responses of the brainstem in ICU patients, with or without brain injury, with alteration of consciousness in relation or not with sedation. The other objectives are to determine the correlations between neurophysiological clinical neurological, or neuroradiological data with delirium occurrence.

The main objective of this study is to determine, in ICU patients with or without brain injury and with alteration of consciousness in relation or not with sedation, if abolition of the cough reflex at Day 1 after admission is predictive of mortality at 28 days, independent from cause for admission and severity.