INFLUENCE OF BODY POSITION ON JUGULAR VENOUS OXYGEN-SATURATION, INTRACRANIAL-PRESSURE AND CEREBRAL PERFUSION-PRESSURE

Elevation of the head as a common practice to reduce raised intracrani al pressure (ICP) has been discussed controversially of late. Some inv estigators were able to show that besides lowering ICP head elevation may also reduce cerebral perfusion pressure (CPP). For a new evaluatio n of optimal head position in neurosurgical care it would be of import ance to know the influence of body position on cerebral perfusion. We therefore employed continuous jugular venous oximetry, monitoring cere bral oxygenation, to study the effect of 0-degrees, 15-degrees, 30-deg rees, and 45-degrees head elevation on ICP, CPP and jugular venous oxy gen saturation (SJVO2) in 25 comatose patients with reduced intracrani al compliance. As expected, head elevation significantly reduced ICP f rom 19.8 +/- 1.3 mmHg at 0-degrees to 10.2 +/- 1.2 mmHg at 45-degrees. Already at 30-degrees 92% of the possible effect on ICP was detected. There was no statistically significant change in CPP and SJVO2 associ ated with varying head position. Individual reactions of CPP to change s in head position, however, were quite unpredictable. The data sugges t that an individual approach to head elevation is to be prefered. A m oderate head evelation between 15-degrees and 30-degrees significantly reduces ICP and, in general, does not impair cerebral perfusion. Jugu lar venous oximetry may be used to optimize ICP, CPP and cerebral oxyg enation.