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EVOKED POTENTIALS PREDICT DEATH IN COMATOSE PATIENTS.

The ability of physicians to predict recovery in comatose patients has important ethical and economic implications. These Austrian researchers examined whether measuring sensory evoked potentials can predict death among comatose patients in an intensive care unit. In this procedure, the median nerve is stimulated and electrodes assess neuronal conduction from the periphery to the cerebral cortex; an evoked potential called N20 indicates the presence of cortical function.

The study included 441 adults with nontraumatic coma; the most common causes were hypoxia/ischemia (49 percent), hepatic coma (10 percent), and sepsis with multiorgan failure (10 percent). Evoked potentials were recorded within seven days of the onset of coma, and the results were withheld from the treating physicians, who provided aggressive care.

All 86 patients with absent bilateral N20 peaks died without regaining consciousness. Of the remaining 355 patients with a preserved N20 peak, 42 percent survived, and most were able to perform activities of daily living.

Comment: In this study, the absence of N20 evoked- potential peaks predicted death with 100 percent certainty, and was noted in about a third of patients who died. The authors believe that intensive care should be withdrawn from adults with nontraumatic coma and absent cortical evoked potentials, but it will be interesting to see whether ICU policy-makers agree.

— AS Brett

Published in Journal Watch General Medicine July 12, 1996

Citation(s):

Madl C et al. Detection of nontraumatic comatose patients with no benefit of intensive care treatment by recording of sensory evoked potentials. Arch Neurol 1996 Jun 53 512-516.

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