Ventilator-associated pneumonia in severe traumatic brain injury: the clinical significance of admission chest computed tomography findings

Abstract

BackgroundVentilator-associated pneumonia (VAP) in severe traumatic brain injury (STBI) is a significant morbidity. Bilateral dependent consolidation (BDC) can be seen on admission chest computed tomography (CCT) in STBI. We hypothesize that this finding may be associated with VAP. Materials and methodsWe retrospectively studied patients who sustained STBI after blunt injury and survived >48 h, who were admitted over a 40-mo period. We defined STBI as an admission Glasgow Coma Scale Score ≤8. We identified VAP by an elevated white blood cell count, a new infiltrate on chest x-ray, and a positive respiratory culture in a ventilated patient. Variables included demographics, injury, admission CCT, and culture data. We compared BDC-positive and BDC-negative patients. ResultsThere were 33 cases of VAP in 94 study patients (35.1%), in whom the incidence of intracranial pressure (ICP) monitoring (66.7% versus 39.3%; P = 0.011) was significantly increased. Ventilator-associated pneumonia was significantly increased in the 28 patients (29.8%) in the BDC-positive group (16 [57.1%] versus 17 (25.6%); P = 0.004). Bilateral dependent consolidation independently predicted VAP. In the 33 VAP cases, gram-negative organisms were present in 27 patients (81.8%), with a predominance of Enterobacteriaceae (16 patients [48.5%]). Culture results did not significantly differ between the early (<4 d) versus late or BDC-positive versus BDC-negative VAP groups. ConclusionsVentilator-associated pneumonia is common after STBI, and BDC is independently associated; however, there is no predilection for specific organisms. Admission CCT findings may prove useful in identifying a group of STBI patients at higher risk for VAP.