Brain tissue pO2 related to SjvO2, ICP, and CPP in severe brain injury

The aim of this report is to present first experience in comparing the course of brain tissue oxygen pressure values (PtiO2) to changes in jugular vein oxygen saturation (SjvO2), intracranial pressure (ICP), and cerebral perfusion pressure (CPP) after severe brain injury. PtiO2 monitoring was done using a polarographic Clark type microcatheter (LICOX pO2 probe) (GMS, Kiel, Germany) with a diameter of 0.5 mm and a sensitive area 7.9 mm long inserted in a right frontal position. The microcatheter was connected to a LICOX pO2 device. A fiber-optic catheter was used to measure SjvO2 and placed into the right internal jugular vein. The ICP monitoring was performed with a fiber-optic intraparenchymal device (Camino Laboratories, San Diego, Calif.) inserted in a left frontal position. Consistent correlations could be noticed between reduced PtiO2 and higher ICP and lower CPP levels. However, the absolute value of a single SjvO2 data point seemed to be less relevant diagnostically than its trend over a period of time. Owing to their experience, the authors suppose that PtiO2 monitoring will be a very important and reliable tool in the treatment of brain injury in the future, especially in its correlation to ICP and CPP.