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: Poly-trauma 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 1 was obtained in 114 patients [mean (SD): 0.89 (0.02)], whereas CvJO(2) greater than 1 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 1 together with accepted clinical criteria (unresponsive coma with brainstem areflexia) provides non-invasive assessment of cerebral circulatory arrest that can help to suspect brain death.