Early SjvO2 monitoring in patients with severe brain trauma

Objective: To investigate early cerebral variables after minimal resuscitation and to compare the adequacy of a cerebral perfusion pressure (CPP) guideline above 70 mmHg, with jugular bulb venous oxygen saturation (SjvO(2)) monitoring in a patient with traumatic brain injury (TBI). Design: Prospective, observational study. Setting: Anesthesiological intensive care unit. Patients: 27 TBI patients with a postresuscitation Glasgow Coma Scale score less than 8. Intervention: After initial resuscitation, cerebral monitoring was performed and CPP increased to 70 mmHg by an increase in mean arterial pressure (MAP) with volume expansion and vasopressors as needed. Measurements and results: MAP, in tracranial pressure (ICP), CPP, and simultaneous arterial and venous blood gases were measured at baseline and after treatment. Before treatment, 37 % of patients had an SjvO(2) below 55 %, and SjvO(2) was significantly correlated with CPP (r = 0.73, p < 0.0001). After treatment, we observed a significant increase (p < 0,0001) in CPP (78 +/- 10 vs 53 +/- 15 mmHg), MAP (103 +/- 10 vs 79 +/- 9 mmHg) and SvjO(2) (72 +/- 7 vs 56 +/- 12), without a significant change in ICP (25 +/- 14 vs 25 +/- 11 mmHg). Conclusion: The present study shows that early cerebral monitoring with SjvO(2) is critical to assess cerebral ischemic risk and that MAP monitoring alone is not sensitive enough to determine the state of oxygenation of the brain. SjvO(2) monitoring permits the early identification of patients with low CPP and high risk of cerebral ischemia. In emergency situations it can be used alone when ICP monitoring is contraindicated or not readily available. However, ICP monitoring gives complementary information necessary to adapt treatment.