Nosocomial Pneumonia

Nosocomial pneumonia, or hospital acquired pneumonia, occurs 48 h or more after admission. It is estimated that its incidence is ∼4–8 episodes per 1,000 hospitalizations. With a mortality rate between 33 and 50%, nosocomial pneumonias have the highest mortality rate of all types of nosocomial infections. Additionally, the development of a nosocomial pneumonia increases the cost of hospitalization by !40,000 per patient. Several predisposing endogenous host factors and exogenous conditions have been identified. Host risk factors include age >70, chronic lung disease, depressed consciousness, immune deficiency, organ failure, smoking, and low serum albumin. Exogenous risk factors include mechanical ventilation, chest surgery, the presence of an intracranial pressure monitor or nasogastric tube, transport from the ICU for procedures, reintubation, and hospitalization during the fall or winter. Medications such as H-2 blockers or antacid therapy, previous antibiotic exposure, steroids, and immunosuppressive drugs may also predispose patients to nosocomial pneumonia. While most cases occur in nonventilated patients, the rate of infection is increased 20-fold in ventilated patients.