NONINVASIVE MONITORING OF REGIONAL CEREBRAL OXYGEN-SATURATION - EXPERIENCES IN INTENSIVE-CARE MEDICINE

Regional cerebral oxygen saturation (rSO(2)) was studied in 15 healthy volunteers aged between 23 and 53 years (mean age: 34.2 +/- 8.7 years) and in 17 intensive care patients (mean age: 37.2 +/- 18.6 years; range 17-70). An infrared spectroscopy technique (INVOS(R) 3100, Somanetics Co.) was used. The results were analysed in terms of age, heart rate, temperature at the recording site, blood pressure and peripheral oxygen saturation. The mean +/- SD of rSO(2) was 69.4 % +/- 7.0 % in the healthy volunteers and 66.4 % +/- 7.4 % in intensive care patients (65.3 % +/- 6.2 % in 7 patients with a cerebral lesion, 67.1 % +/- 8.4 % in 10 patients with no cerebral lesion). Individual examples are presented to show that infrared spectroscopy is a useful non-invasive method of investigating cerebral oxygenation. However, regional pathological-anatomical limitations of the technique, and possible extracerebral artefacts make necessary a critical interpretation of the rSO(2) values.