Bacteriology of Nosocomial Sinusitis

Nosocomial sinusitis often develops in patients who require extended periods of intensive care (postoperative patients, burn victims, and patients with severe trauma) involving prolonged endotracheal or nasogastric intubation. P. aeruginosa and other aerobic and facultative gramnegative rods are common in sinusitis of nosocomial origin (especially in patients who have nasal tubes or catheters), the immunocompromised, patients with human immune deficiency viral infection and patients who suffer from cystic fibrosis (17,47).

Nasotracheal intubation places the patient at a substantially higher risk for nosocomial sinusitis than orotracheal intubation. Approximately 25% of patients requiring nasotracheal intubation for more than five days develop nosocomial sinusitis (48). In contrast to community-acquired sinusitis, the usual pathogens are gram-negative enterics (i.e., P. aeruginosa, K. pneumoniae, Enterobacter spp., P. mirabilis, Serratia marcescens) and aerobic gram-positive cocci (occasionally streptococci and staphylococci). Whether these organisms are actually pathogenic is unclear as their recovery may represent only colonization of an environment with impaired mucociliary transport and foreign body presence in the nasal cavity.

Evaluation of the microbiology of nosocomial sinusitis in nine children with neurologic impairment revealed anaerobic bacteria, always mixed with aerobic and facultative bacteria, in six (67%) sinus aspirates and aerobic bacteria only in three (33%) (49). There were 24 bacterial isolates, 12 aerobic or facultative, and 12 anaerobic. The predominant aerobic isolates were K. pneumoniae, E. coli, and S. aureus and P. mirabilis, P. aeruginosa, H. influenzae, M. catarrhalis, and S. pneumoniae. The predominant anaerobes were Prevotella spp., Peptostreptococcus spp., F. nucleatum, and B. fragilis. Organisms similar to those recovered from the sinuses were also found in the tracheostomy site and gastrostomy wound aspirates in five of seven instances. This study demonstrates the uniqueness of the microbiologic features of sinusitis in neurologically impaired children, in which, in addition to the organisms known to cause infection in children without neurologic impairment, aerobic, facultative and anaerobic gram-negative organisms that can colonize other body sites are predominant.

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