Cerebral Oxygen Desaturation with Normal ICP and CPP in Severe TBI

Introduction: Standard monitoring of severe traumatic brain injury patients (TBI) by intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring fails to recognize episodes of cerebral oxygen desaturation. We found and characterized frequent episodes of desaturation of jugular venous oxygen (SjO2) in the face of normal ICP and CPP. Methods: Fifty six patients with severe TBI had SjO2 and ICP monitors placed. The charts were retrospectively reviewed and all episodes of desaturation were recorded and characterized. Results: Nineteen patients had episodes of desaturation with normal ICP and CPP. The average GCS score was 5.8. 63% of desaturations occurred in the first 24 hours, 17% of desaturations occurred in 24-48 hours, and 20% occurred in 48-72 hours. The depth of desaturation was 50-54% in 50% of instances, 45-49% in 37% of instances, and 40-44% in 13% of in- stances. The duration of the desaturation episodes was less than 10 minutes in 47%, 10-30 minutes in 17%, 30-60 minutes in 23%, and greater than 50 minutes in 13%. Treatment of the desaturation was elevation of FIO2 in all patients, elevation of pCO2 in 15 patients, volume expansion in 9 patients, pressors in 9 patients, and Propofol in 5 patients. Conclusions: The monitoring of severe TBI patients with ICP and CPP alone is insufficient to recognize cerebral oxygen de- saturation episodes in 34% of patients. The monitoring of SjO2 facilitates the recognition and treatment of these episodes.