Insulin, intracerebral glucose and bedside biochemical monitoring utilizing microdialysis

Following subarachnoid hemorrhage, hyperglycemia is strongly associated with complications and with impaired neurological recovery. Targeted insulin therapy for glycemic control might, on the contrary, have harmful effects by causing too low cerebral glucose levels. The study published by Schlenk and colleagues in the previous issue of Critical Care shows that insulin caused a significant decrease in the interstitial cerebral glucose concentration although the blood glucose level remained unaffected. Since several studies utilizing various analytical techniques have shown that cerebral blood flow and cerebral glucose uptake and metabolism are insulin-independent processes, the observation remains unexplained.