The effect of fiberoptic bronchoscopy on cerebral hemodynamics in patients with severe head injury

Abstract

Study objective: Concerns exist about the effect of flexible fiberoptic bronchoscopy (FFB) on intracranial pressure (ICP). We studied the effect of FFB on cerebral hemodynamics in patients with severe head injury.

Design: Prior to FFB, patients were anesthetized and muscle relaxants were given as necessary to eliminate coughing. Comparisons were made of mean arterial pressure (MAP), ICP, and cerebral perfusion pressure (CPP) prior to, during, and after FFB, as well as comparisons of mean cerebral hemodynamic values in an 8-hour period before and after FFB. Observations were made of changes in neurologic status post-FFB.

Setting: Surgical intensive care unit of Level 1 Trauma Center.

Patient population: Fifteen patients with severe head injury in whom ICP was monitored and who required FFB for diagnosis of nosocomial pneumonia or treatment of lobar collapse.

Results: Pre-FFB ICP averaged 14.3 mm Hg (range, 6 to 26 mm Hg). During FFB, patients experienced a mean increase in ICP of 13.5 mm Hg above basal values (p = 0.0001). At peak ICP, MAP increased from a baseline of 92.3 mm Hg (SD +/- 16.1) to 111.5 mm Hg (+/- 13.9). Mean CPP was 83.7 mm Hg at peak ICP (range, 52 to 121 mm Hg), a 14.0% increase over baseline. The ICP and MAP returned to basal levels following bronchoscopy. No patient had a clinically significant increase in ICP or demonstrated any deterioration in Glasgow Coma Scale score or neurologic examination findings post-FFB.

Conclusions: Although FFB causes an increase in ICP in patients with severe head injury, MAP also rises, and an adequate CPP is maintained. The ICP returns to basal levels after the procedure. When properly performed, FFB does not adversely affect neurologic status in patients with severe head injury.