Pneumonia in patients with severe head injury: incidence, risk factors, and outcomes

The reported incidence of hospital-acquired bacterial pneumonia in critically ill trauma patients varies from as low as 4% to as high as 87%, with fatality rates varying from 6% to 59%. Clinical studies have identified the risk factors for pneumonia. The authors undertook this retrospective study to evaluate the incidence, risk factors, and outcomes of hospital-acquired bacterial pneumonia in a group of patients with severe head injuries.This was a retrospective review of consecutive adult patients admitted to the neurosurgical ICU in the authors' hospital because of severe head injury (Glasgow Coma Scale scores ≤ 8) between January 2008 and December 2010.During the study period, 290 patients were admitted to the neurosurgical ICU. Multivariate Cox regression analysis showed that age (HR 1.01, 95% CI 1.001-1.02), nasogastric tube insertion (HR 4.56, 95% CI 1.11-18.64), and hemiplegia or hemiparesis (HR 3.79, 95% CI 2.01-7.17) were significantly associated with the development of pneumonia.The authors identified 3 risk factors (age, nasogastric tube insertion, and hemiplegia or hemiparesis) associated with the development of pneumonia in patients with severe head injury. This finding constituted the basis for developing a simple screening tool that can be used to assess the risk of occurrence of pneumonia in such patients.