Cerebral microdialysis: perioperative monitoring and treatment of severe neurosurgical patient.

The early signs of brain ischemia are key indicators of secondary brain injury and their recognition on time can ultimately save life. Direct recording of cerebral ischemia is possible using the method of cerebral microdialysis (CM). This paper presents results of the five-year experience in applying this method at University Department of Neurosurgery, Sarajevo University Clinical Center in Sarajevo. In this observational prospective clinical study, the treatment and outcome of 51 patients with subarachnoid hemorrhage (SAH) and traumatic intracranial hemorrhage (tICH) undergoing neurosurgery and consequently treated conservatively at Neurosurgical Intensive Care Unit (NICU) were analyzed. All patients were followed up by unified monitoring at NICU and additionally by the CM method. Between December 2006 and September 2010, CM monitoring was performed in 51 patients: 18 patients with SAH and 33 patients with tICH. In all patients, samples were obtained on 367 occasions, yielding a total of 3314 samples for biochemical parameters (mean 64.98 per patient, range 42-114 samples). Positive correlation was found between glucose level and outcome at one-year follow up (when glucose level was lower, the patient Glasgow Outcome Scale (GOS) score was worse). The correlation coefficient for glycerol was negative (r=-0.81), and so was for the lactate/pyruvate ratio. There was a significant difference in patient outcome in favor of the group of patients monitored by use of CM in terms of poor and good outcome graded according to GOS score 12 months after the injury compared with the group of patients not monitored with CM (P<0.028). According to our experience, we believe that CM enables early initiation of appropriate therapeutic strategies to overcome cerebral ischemia and secondary brain damage, eventually leading to better patient outcome.