Abstract
Intraoperative investigations of local intracapillary haemoglobin oxygenation have been performed in 5 patients during neurosurgical interventions using the Erlangen micro-lightguide spectrophotometer (EMPHO). As the measurements can be performed in a very short period of time (approximately 60 s) the EMPHO enables rapid monitoring of local haemoglobin oxygenation in the brain. All patients received thiopental anaesthesia and were mechanically ventilated. The local measurements were performed during normoventilation (arterial PCO2-PaCO2 37.8+or-0.7 mm Hg) and hyperventilation (PaCO2 31+or-0.5 mm Hg). Hyperventilation caused a decrease in the mean SO2 from 47.8% to 41.1%. The number of SO2 values 2 values is discussed.