Bedside microdialysis: A tool to monitor cerebral metabolism in subarachnoid hemorrhage patients?*

Abstract

To analyze the time course and changes of cerebral microdialysis parameters after aneurysmal subarachnoid hemorrhage (SAH) in respect to the clinical course (asymptomatic, delayed, and acute ischemic neurologic deficits) to evaluate the method of bedside microdialysis in these patients. Prospective, controlled study during a 3-yr period. Neurosurgical intensive care unit at a primary level university hospital, supervised and staffed by members of both the department of neurosurgery and the department of anesthesiology and intensive care medicine. Ninety-seven patients (51 females/21 males; 52 ± 13 yrs; World Federation of Neurological Surgeons Scale grades 0–5) after aneurysmatic SAH. A microdialysis catheter (CMA 100) was inserted into the region most likely to be affected by vasospasm directly after aneurysm clipping, connected to a pump, and perfused with Ringer solution (0.3 μL/min). The dialysates were collected hourly and analyzed at the bedside for glucose, lactate, lactate-pyruvate ratio, glutamate, and glycerol (CMA 600). Patients were classified according to clinical presentation as being asymptomatic or having acute (AIND) or delayed (DIND) ischemic neurologic deficits. DIND patients (n = 18) had significantly higher lactate and glutamate concentrations on days 1–8 post-SAH and a higher lactate-pyruvate ratio on days 3–8 post-SAH compared with asymptomatic patients (n = 57;p p Cerebral bedside microdialysis is a safe and promising technique for monitoring (impending) regional cerebral ischemia. The dialysate changes can indicate early the onset of delayed neurologic deterioration and are in good accordance with the clinical course of SAH patients. In the future, this technique may be used to monitor the efficacy of the intensive care therapy of these patients.