Serum S100B as a biochemical marker of neurological complications in intensive care patients

Objective

There is growing evidence that S100B protein may be used as a novel biochemical marker of brain cell damage, measured by a simple blood test. Several studies have found increased values in acute neurological diseases such as stroke, head injury, intracerebral haemorrhage or cerebral hypoxia. The objective of our study was to investigate whether measurement of serum S100B is useful to diagnose an acute neurological complication in the analgo-sedated and intubated intensive care patient.

Methods

One hundred and fifty neurointensive care patients with different intracranial diseases were included in our study. Serum S100B protein was measured daily using an immunoluminometric assay (LIAISON^®, Byk-Sangtec Diagnostica, Dietzenbach, Germany). The result of the test was usually available at the bedsite within 3 hours. S100B levels and temporal course were investigated for the sensitivity and specificity to diagnose a neurological complication occurring during the intensive care course.

Results

One hundred and twelve patients (75%) showed primarily increased values due to their neurological disease or after surgery. In 22 patients a complication with neurological deterioration was observed such as vasospastic infarction, brain haemorrhage, or contusion/oedema enlargement. In all of these patients, a significant rise of S100B (> 0.5 μg/l) was found. There was no major complication without S100B increase. In three cases, the increase in S100B was the first sign of neurological complication and prompted emergency computed tomography scanning. In two cases, increasing S100B values changed management towards a surgical intervention.

Conclusion

Serial measurement of S100B protein is suitable to diagnose neurological complications with a high sensitivity and specificity and to have an impact on management decisions in intensive care patients.