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

Abstract 

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.