Ventilator-associated pneumonia in severe traumatic brain injury

Pneumonia is an important cause of morbidity following severe traumatic brain injury (TBI). However, previous studies have been limited by inclusion of specific patient subgroups or by selection bias. The primary objective of this study was to describe the incidence, risk factors for, and outcome of ventilator-associated pneumonia in an unselected population-based cohort of patients with severe TBI. An additional goal was to define the relationship of ventilator-associated pneumonia (VAP) with nonneurological organ dysfunction.

A prospective, observational cohort study was performed at Foothills Medical Centre, the sole adult tertiary-care trauma center servicing southern Alberta. All patients with severe TBI requiring ventilation for more than 48 hours between May 1, 2000 and December 30, 2002 were included.

A total of 60 patients (45%) acquired VAP for an incidence density of 42.7/1000 ventilator days. Patients with polytrauma were at higher risk (risk ratio 1.7, 95% confidence interval, 0.9-3.1) for development of VAP than those with isolated head injury. Development of VAP was associated with a significantly greater degree of nonneurological organ system dysfunction. Although VAP was not associated with increased hospital mortality, patients who developed VAP had a longer duration of mechanical ventilation (15 versus 8 days, p < 0.0001), longer intensive care unit (17 versus 9 days, p < 0.0001) and hospital (60 versus 28 days, p = 0.003) lengths of stay, and more often required tracheostomy (35 versus 18%, p = 0.003).

VAP occurs frequently and is associated with significant morbidity in patients with severe TBI.