Cerebral microdialysis monitoring

Cerebral metabolic monitoring was performed using an intra-parenchymal CMA 70 catheter with a 20 kDa cut-off, perfused with artificial cerebrospinal fluid via a CMA 106 pump at a rate of 0.3 μL/min (CMA Microdialysis AB, Stockholm, Sweden). Brain extracellular samples were collected every 60 min and immediately analyzed at the bedside for concentrations of glucose, lactate, and pyruvate, using a kinetic enzymatic analyzer (ISCUS^flex; CMA Microdialysis AB). The CMD catheter was inserted in the operating room by an experienced neurosurgeon through a multiple-lumen bolt (Integra Neurosciences, Plainsboro, NJ) and was placed in the right frontal lobe, in apparently normal sub-cortical white matter. Adjacent to the CMD catheter, a Codman^® ICP monitor (Codman, Raynham, MA) was inserted for continuous measurement of ICP. The appropriate location of all monitors was assessed by a follow-up head CT scan, performed within the first 24 h from intensive care unit (ICU) admission.