PAPER Normal jugular bulb oxygen saturation

Background: Normal values of the jugular bulb oxygen saturation were obtained in 1942 and in 1963. Correct catheter positioning was not confirmed radiologically. Objectives: To replicate the measurements during angiographic catheterisation of the jugular bulb. Methods: Oxygen saturation in the jugular bulb (SjO2), inferior petrosal sinus (SipsO2), and internal jugular vein was bilaterally measured in 12 patients with Cushing’s syndrome undergoing selective bilateral catheterisation of the inferior petrosal sinus. In addition, data from the two old series were reanalysed for comparison. Results: SjO2 values (44.7%) were significantly lower than in the two old series, particularly concern-ing the normal lower limit (54.6 % and 55.0 % respectively). Comparative analysis suggests that con-tamination with the extracerebral blood of the facial veins and inferior petrosal sinuses was responsible for falsely high SjO2 values in the two old series. Conclusions: The normal lower SjO2 limit is lower than previously recognised. This may have practi-cal implications for treating severe head trauma patients. Monitoring of jugular bulb vascular oxygen saturation(SjO2) is currently suggested in patients with severehead trauma as a global measure of the adequacy of the cerebral blood flow (CBF) to brain metaboli