CEREBRAL VENOUS OXYGEN-SATURATION MONITORING - IS DOMINANT JUGULAR BULB CANNULATION GOOD ENOUGH

Venous oxygen saturation at the clinically dominant jugular bulb (SjO( 2)) and that at the confluence of the cerebral sinuses (SCCSO2) were c ompared by direct simultaneous blood sampling of 13 severely head inju red patients. The side of dominant jugular bulb (JB) was determined by neck compression test. The right side was chosen if the test was equi vocal. In effect, the right side was cannulated in all cases. Subseque nt angiography showed that two of the 13 cases were left side dominant . In all, 176 pairs of blood samples were analysed. Correspondence rat es (the difference between each pair of blood samples being less than 4% of oxygen saturation) for individual case were good (80-100%) in ni ne cases including one case with left side dominance. Correspondence r ates were moderate in two cases (50 and 56%); the differences were not clinically significant. In the remaining two cases, including one wit h left side dominance, the correspondence rates were poor (0 and 4%, r espectively); SCCSO2 was always lower than SjO(2); median differences were 13.4 and 23.1%. Ischaemia in the cerebral hemispheres would have been underestimated if management were based on SjO(2). Monitoring at the dominant JB accurately reflected the global and hemispheric cerebr al oxygenation in 11/13 of cases. Monitoring at the non-dominant JB is not recommended.