493: MULTIMODAL NEUROMONITORING: CEREBRAL MICRODIALYSIS IN A CASE OF INTRACEREBRAL HEMORRHAGE

Abstract

Introduction: Cerebral Microdialysis (CMD) is a FDA approved multimodal invasive monitor technique that provides measurements of local brain metabolism via continuous sampling of interstitial brain fluid at bedside. Past applications in TBI and SAH show that acute brain injury (ABI) can lead to metabolic crisis reflected by changes in cerebral glucose, pyruvate and lactate. Limited literature exists on CMD in spontaneous intracerebral hemorrhage (ICH). Description: A 45 year old woman presented with a GCS of 8T and a 89 cc left frontal ICH with ventricular involvement and 9 mm of midline shift. She underwent craniotomy and minimally invasive perifascicular surgery with BrainPath (NICO, IN) for evacuation. Intraoperatively, Quad Lumen Bolt (Hemedex, MA) with CMD (M-Dialysis, MA), PbtO2 (Licox, Integra, NJ) and ICP (Camino, Natus, CA) monitors were placed in the peri-hematoma region. Post operatively, mean ICP was normal (13.2 +/- 4.7 mm Hg) though mean brain tissue oxygen (5.4 +/- 4 mmHg) and glucose (13.9 +/- 4.9 mg/dl) were low and lactate/pyruvate ratio (65.8 +/- 16 mmol/L) was high. Due to concern for metabolic crisis, poor exam and hydrocephalous on head CT, the patient underwent external ventricular drainage (EVD). Post EVD, mean ICP (8.8 +/- 2.7 mmHG) and L/P ratio (31.4 +/- 9 mmol/L) decreased, and PbtO2 (23.8 +/- 11 mmHg) and glucose (26.2 +/- 6.1 mg/dl) increased. All pre and post EVD changes were statistically significant on student-test (P<.05). Monitors were removed without complication. The patient was discharged to nursing facility with a modified rankin scale of 4. Discussion: Here we demonstrate the safe implementation of CMD in ICH and the use of CMD in tandem with PbtO2/ICP to guide treatment in ICH. Despite a normal ICP, numerous cerebral metabolic derangements existed and improved after CSF diversion. A normal ICP may not reflect underlying metabolic-substrate demands of the brain during acute brain injury. CMD and PbtO2 monitoring augment traditional ICP monitoring in brain injury. Further prospective studies will need to be performed to understand the interplay between ICP, cerebral metabolic and PbtO2 in ABI.