RT Journal Article SR Electronic T1 Normal jugular bulb oxygen saturation JF Journal of Neurology, Neurosurgery & Psychiatry JO J Neurol Neurosurg Psychiatry FD BMJ Publishing Group Ltd SP 784 OP 786 DO 10.1136/jnnp.74.6.784 VO 74 IS 6 A1 A Chieregato A1 F Calzolari A1 G Trasforini A1 L Targa A1 N Latronico YR 2003 UL http://jnnp.bmj.com/content/74/6/784.abstract AB 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 concerning the normal lower limit (54.6% and 55.0% respectively). Comparative analysis suggests that contamination 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 practical implications for treating severe head trauma patients.