SSEP amplitude for prognostication in post-anoxic coma: A further step towards standardisation

Recent sttudies have shown that short-latency somatosensory (SSEP) amplitude as a predictor of outcome in post-anoxi coma is a continuous – rather than a dichotomous – variable. In addition, these studies showed that low-voltage SSEP is as reliable as a bilaterally absent SSEP for predicting severe hypoxic-ischaemic brain injury. Inevitably, when continuous variables are used to predict a dichotomous outcome (good vs. poor), there is a trade-off between sensitivity and specificity along the values of these variables, and we need to establish a threshold value to maximise the measure of accuracy that is more clinically relevant (in this case, specificity). The major problem with this approach is that these thresholds are often inconsistent across studies.