Relationship between early patterns of cerebral extraction of oxygen and outcome from severe acute traumatic brain swelling: cerebral ischemia or cerebral viability?

OBJECTIVE

To evaluate outcome from severe acute traumatic diffuse brain swelling, in relation to early patterns of global cerebral extraction of oxygen.

DESIGN

Prospective, interventional study.

SETTING

Neuroscience intensive care unit of a university hospital.

PATIENTS

Adults (n = 205) with acute, essentially isolated brain trauma (predominantly diffuse brain swelling), undergoing routine early monitoring of cerebral extraction of oxygen and intracranial pressure, along with other monitoring modalities.

INTERVENTIONS

Routine neuroemergency procedures.

MEASUREMENTS AND MAIN RESULTS

Cerebral extraction of oxygen (arteriojugular oxyhemoglobin saturation difference) was measured in each patient, early in the acute phase (2 to 8 hrs postinjury). Outcome at 6 months postinjury was significantly better in patients with initially increased cerebral extraction of oxygen (>42%) than in those patients with normal (24% to 42%) or decreased (<24%) values. In contrast, no significant differences were found among these three groups with respect to age, initial Glasgow Coma Scale score, intracranial pressure, cerebral perfusion pressure, PaCO2, total hemoglobin content, and time from injury when the initial measurements were performed.

CONCLUSIONS

Initially increased cerebral extraction of oxygen appears to indicate global cerebral viability rather than cerebral ischemia in patients with acute traumatic diffuse brain swelling.