Hypotension, Hypoxia, and Head Injury

Abstract

BRAIN INJURY is a major cause of death following trauma. The traumatized brain is highly vulnerable to secondary brain injuries, which can be caused by seizures, an elevated temperature, hypoxia, and hypotension. These latter 2 insults may occur immediately after injury, when the brain is most susceptible to ischemia. Retrospective studies^1,2 from large databases (the Traumatic Coma Data Bank and the National Pediatric Trauma Registry) have suggested that early hypotension following brain injury doubles the mortality. The influence of hypoxia alone on mortality is less dramatic, but has not been intensively studied in a prospective fashion. In addition, little is known about the outcome of patients who have sustained early secondary brain injuries but survived. We undertook this investigation to prospectively study the frequency and duration of secondary brain insults occurring during the early resuscitative phase following severe to moderate head injury. We hypothesized that early episodes of hypoxia and hypotension would have a significant impact on the outcome following traumatic brain injury.