Adjunctive aerosolized colistin for multi-drug resistant gram-negative pneumonia in the critically ill: a retrospective study

• Published in: BMC anesthesiology 2013-11, Vol.13 (1), p.45-45, Article 45
• Main Authors: Doshi, Neha M, Cook, Charles H, Mount, Kari L, Stawicki, Stanislaw P, Frazee, Erin N, Personett, Heather A, Schramm, Garrett E, Arnold, Heather M, Murphy, Claire V
• Format: Article
• Language: English
• Subjects: Acinetobacter; Acinetobacter infections; Bacterial pneumonia; Care and treatment; Colistin; Critically ill; Diagnosis; Dosage and administration; Drug dosages; Drug resistance in microorganisms; Drug therapy; Health aspects; Hospitals; Intensive care; Medical care; Mortality; Organisms; Pharmacy; Pneumonia; Pseudomonas; Pseudomonas infections; Quality management; Review boards; Staphylococcus infections; Statistical analysis; Studies; Transplants & implants
• ISSN: 1471-2253; 1471-2253
• DOI: 10.1186/1471-2253-13-45

The incidence of multi-drug resistant (MDR) gram-negative (GN) organisms including Pseudomonas and Acinetobacter spp has increased in the last decade, prompting re-evaluation of colistin for the management of these infections. Aerosolized colistin as an adjunct to intravenous therapy is a current option for the management of MDR-GN pneumonia, although data supporting this practice is limited. This study evaluates the efficacy of adjunctive aerosolized colistin in combination with intravenous colistin in critically ill patients with MDR-GN pneumonia. A retrospective multi-center cohort analysis comparing critically ill patients with MDR-GN pneumonia who received intravenous colistin (IV) alone or in combination with adjunctive aerosolized colistin (IV/AER) with a primary endpoint of clinical cure at the end of colistin therapy. Secondary endpoints included microbiologic cure, duration of mechanical ventilation, length of stay, and hospital mortality. A post-hoc subgroup analysis was performed for patients with high quality cultures used for diagnosis of MDR-GN pneumonia. Dichotomous data were compared using Fisher's exact test while the student's t-test or Mann-Whitney U test were used for continuous variables. Ninety-five patients met criteria for evaluation with 51 patients receiving IV and 44 receiving IV/AER. Baseline characteristics were similar between the two groups. Twenty patients (39.2%) receiving IV and 24 (54.5%) receiving IV/AER achieved clinical cure (p = 0.135). There was no difference in microbiologic cure rates between the IV and IV/AER colistin groups (40.7vs. 44.4%, p = 0.805). The IV group demonstrated a trend towards higher pneumonia attributable mortality (70.4 vs. 40%, p = 0.055). In the subgroup analysis of patients with high quality respiratory cultures, there was a significantly lower clinical cure rate for those in the IV group as compared to the IV/AER group (31.3 vs. 57.1%, p = 0.033). Addition of aerosolized colistin to IV colistin may improve clinical cure and mortality for patients with MDR-GN pneumonia. Larger, prospective trials are warranted to confirm the benefit of adjunctive aerosolized colistin in critically ill patients with MDR-GN pneumonia.