Diagnosis of ventilator-associated pneumonia may be difficult because many other processes may cause pulmonary infiltrates and fever, and cultures obtained by suctioning secretions through the endotracheal tube do not reliably differentiate between pneumonia and bacterial colonization of the trachea. In confusing cases, use of the fiberoptic bronchoscope to obtain specimens with a protected brush or quantitative cultures of bronchial lavage fluid may be helpful. In addition, a recent study found that continuous aspiration of subglottic secretions via a modified endotracheal tube resulted in a significant reduction in pneumonia. Reintubation is associated with an increased incidence of nosocomial pneumonia, the risk of which may be lessened by prevention of premature extubation. Selective decontamination of the oropharynx and gastrointestinal tract by nonabsorbable antibiotics reduces bacterial colonization but does not clearly decrease the incidence of serious pneumonia and has no effect on mortality.
Nosocomial sinusitis is strongly related to the nasotracheal route of intubation.
Computed tomography demonstrates fluid in the maxillary sinus in over 70 percent of patients who undergo both nasotracheal and nasogastric intubation for one week, as compared with only 34 percent of those in whom endotracheal and feeding tubes are placed via the oral route. Aspiration of the sinus may reveal nonpurulent mucoid fluid, but in a significant number of cases, sinusitis will be evidenced by aspiration of pus with positive stains and cultures for bacteria. Treatment of nosocomial sinusitis includes antibiotic therapy, replacement of nasotracheal and nasoenteral tubes with tubes placed via the oral route, and use of decongestants and head elevation to help facilitate drainage. A number of mechanical problems can arise during the period of ventilatory support, and in some cases, these may be life threatening. Inadequate humidification can lead to excessive drying of airway secretions and damage to the tracheobronchial mucosa.