Early onset pneumonia: risk factors and consequences in head trauma patients

Early onset pneumonia occurs frequently in head trauma patients, but the potential consequences and the risk factors of this event have been poorly studied.

This prospective observational study was undertaken in the surgical intensive care unit of a university teaching hospital in Clichy, France. Head trauma patients requiring tracheal intubation for neurologic reasons and ventilation for at least 2 days were studied to assess the risk factors and the consequences of early onset pneumonia.

During a 2-yr period, 109 head trauma patients were studied. The authors found an incidence of early onset pneumonia of 41.3%. Staphylococcus aureus was the most common bacteria involved in early onset pneumonia. Patients with early onset pneumonia had a lower worst arterial oxygen tension:fraction of inspired oxygen ratio, more fever, more arterial hypotension, and more intracranial hypertension, factors known to worsen the neurologic prognosis of head trauma patients. Nasal carriage of S. aureus on admission (odds ratio, 5.1; 95% confidence interval, 1.9-14.0), aspiration before intubation (odds ratio, 5.5; 95% confidence interval, 1.9-16.4) and barbiturate use (odds ratio, 3.9; 95% confidence interval, 1.2-12.8) were found to be independent risk factors of early onset pneumonia.

The results suggest that early onset pneumonia leads to secondary injuries in head-injured patients. Nasal carriage of S. aureus, aspiration before intubation, and use of barbiturates are specific independent risk factors for early onset pneumonia and must be assessed to find and evaluate strategies to prevent early onset pneumonia.