Sinusitis in mechanically ventilated patients and its role in the pathogenesis of nosocomial pneumonia.

Nosocomial sinusitis is a complication of endotracheal intubation and mechanical ventilation in critically ill patients. Its incidence is often underestimated because of a lack of clinical signs. It is suspected in patients with nasal discharge or unexplained fever. Its diagnosis is based on radiological examination, by radiograph or computed tomography scan, and microbiological cultures of maxillary sinus aspirate. Maxillary sinusitis is often associated with involvement of the sphenoid, ethmoid, and/or frontal sinuses. Its incidence varies greatly according to diagnostic criteria and the population studied. Infectious sinusitis is less frequent than noninfectious sinusitis, occurring in 20 to 30% of patients intubated for at least seven days. Its incidence is higher in nasotracheally than in orotracheally intubated patients. Other risk factors include nasogastric tubes and head trauma. The main causative agents are gram-negative bacilli, primarily Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacteriaceae, but Staphylococcus aureus and yeasts are also common. Patients with nosocomial sinusitis are more likely to develop pneumonia than those without sinusitis. The sinus provides a bacterial reservoir from which organisms may seed the tracheobronchial tree. The association of sinusitis and pneumonia is mainly due to Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter baumannii. The treatment of sinusitis is based on the removal of all nasal tubes, topical decongestants, and maxillary sinus drainage and lavage. The role of intravenous antibiotics is controversial.