Usefulness of venous oxygen saturation in the jugular bulb for the diagnosis of brain death: report of 118 patients

Objective: To assess the usefulness of venous oxygen saturation in the jugular bulb (SjO 2 ) as a complementary test for the diagnosis of brain death. Design: Prospective observational study. Setting: Polytrauma intensive care unit (ICU) of an acute-care teaching hospital in Santander, Spain. Patients: We studied 118 (44%) out of 270 patients with severe head injury and intracranial hemorrhage meeting criteria of brain death (lack of cardiac response to atropine, unresponsive apnea, and iso-electric EEG in the absence of shock, hypotension and treatment with muscle relaxants and/or central nervous system (CNS) depressant drugs). Measurements and results: At the moment at which clinical diagnosis of brain death was made and an iso-electric EEG was obtained, simultaneous oxygen saturation in central venous blood (right atrium) (SvO 2 ) and jugular venous bulb (SjO 2 ) samples was measured. The ratio between SvO 2 and SjO 2 , expressed as CvjO 2 (the so-called central venous-jugular bulb oxygen saturation rate; CvjO 2 = SvO 2 /SjO 2 ) was calculated. CvjO 2 less than I was obtained in 114 patients [mean (SD): 0.89 (0.02)], whereas CvjO 2 greater than I was obtained in only 4 (3.38%). In the group of 152 survivors, a single patient was discharged from the ICU in a vegetative state in which CvjO 2 was below 1. CvjO 2 as a complementary test for the diagnosis of brain death showed 96.6% sensitivity, 99.3% specificity, and 99.1% and 97.4% positive and negative predictive values, respectively. Conclusion: Central venous-jugular bulb oxygen saturation rate below I together with accepted clinical criteria (unresponsive coma with brain-stem areflexia) provides non-invasive assessment of cerebral circulatory arrest that can help to suspect brain death.