Use of nebulized antimicrobial agents in burned and mechanically ventilated patients with persistent Acinetobacter baumannii, Pseudomonas aeruginosa, or Enterobacteriacea.

BACKGROUND: Nebulized antibiotics are used to locally treat colonizations of multi-resistant organisms. Prior systemic nephrotoxic antibiotic use with serum creatinine rises warranted an alternative therapy in 69 ventilator-dependent patients with persisting sputum cultures and need for ventilatory support. MATERIALS AND METHODS: Following IRB approval, retrospective patient data were reviewed. Analysis included comparison of these 69 patients (71 treatments) to 142 Gram-negative infected burn patients matched for age and burn size. RESULTS: Mean pooled age and burn wound percent for the 71 triplicates (n=211 patients) were 55.6±18.3 years and 27.4±22.3% burns. Fifty-seven of 69 (83%) patients had inhalation injuries and 54 of 69 (78%) patients survived. Nebulizations averaged 6.8±3.3 days (range 3-12 days). Serum creatinine rose in 2 patients receiving colistimethate nebulizations, known to cause nephrotoxicity following nebulization. Triplicate comparisons via ANOVA noted prolonged ventilatory support (F=13.39; p≪0.05) and length of stay (F=6.11; p≪0.5). Variance was attributed to the sicker nebulized patients. Twenty-four inhalation injury-only triplicates further confirmed that nebulized patient subgroup was more ill. CONCLUSION: Short duration antibiotic nebulization may allow higher intra-tracheal antibiotic concentrations and may facilitate weaning from the ventilator by reducing bacterial bioburden.