Reliability of calcium-binding protein S100B measurement toward optimization of hyperosmolal therapy in traumatic brain injury

BACKGROUND: Osmotherapy is a cornerstone for the management of severe Traumatic Brain Injury (TBI). Hypertonic saline (HTS) has advantages as being preferred osmotic agent, but there is inadequte knowledge regarding dose and its saftey in comparison to mannitol. S100B, as a specific neuroinflammatory biomarker in TBI might be a reliable therapeutic index following osmotic therapy. AIM: To compare both administration ways of HTS 5% (bolus and infusion) with mannitol upon S100B as a therapeutic tool for monitoring treatment in TBI patients. METHOD: Adult patients wih modrate to severe TBI were recruited and have randomly received one of the three protocols: 125 cc of HTS 5% every 6 hrs (N: 11) as bolus; 500 cc of HTS 5% (N: 12) as infusion for 24 hrs; or 1 g/kg mannitol of 20% (N: 10) as a bolus, repeated with a dose of 0.25-0.5 g/kg every 6 hrs based on patient's response for 3 days. Serum S100B, blood pressure, serum sodium and osmolality and Glascow coma score (GCS) were measured at baseline and daily for 3 days. RESULTS: Initial serum S100B level in TBI patients was higher than control group (p < 0.0001). Levels of measured S100B have decreased for all treatment groups, but reduction wasn't significantly after hyperosmolal therapy. GCS level increased significantly in infusion group (p = 0.002) and there were negative and significant correlation between serum S100B level and GCS level in some days. Mean arterial pressure increased significantly in HTS groups (bolus: p = 0.002, infusion < 0.0001). CONCLUSIONS: S100B is closely related to the pathophysiological mechanism in TBI and may be useful as a therapeutic tool for treatment monitoring in TBI patients HTS is a safe and effective osmotic agent in TBI setting.