Efficacy and safety of adjunctive nebulized colistin sulfate for multidrug-resistant Gram-negative bacteria pneumonia: a retrospective comparative cohort study.

ABSTRACT

BACKGROUND: The incidence of multidrug-resistant Gram-negative bacteria (MDR-GNB) pneumonia has increased in the last decade. If antibiotics are given only through intravenous, the antibiotic concentrations in lung tissue will be insufficient. Recently, nebulized antibiotics have shown effectiveness as an adjunctive therapy with intravenous antibiotics for resistant strains. Therefore, the goal of this study was to assess the efficacy and safety of adjunctive nebulized colistin sulfate in combination with intravenous antibiotics in patients with MDR-GNB pneumonia. METHODS: A total of 203 patients who were infected with MDR-GNB pneumonia were selected. Based on whether patients received nebulized colistin sulfate, patients were divided into 2 groups the NCIA group (nebulized colistin sulfate in combination with intravenous antibiotics) and the IA group (intravenous antibiotics without nebulized colistin sulfate). After propensity score matching (PSM) analysis, we compared the efficacy in terms of favorable clinical outcomes, the bacteria detection rate, days of hospital stay, days of intensive care unit (ICU) stay, days of mechanical ventilation (MV), antipyretic time, days of antibiotic therapy, and 28-day all-cause mortality. Safety was also compared between groups. RESULTS: A total of 116 patients met the criteria for evaluation, with 46 patients in the NCIA group and 70 patients in the IA group. After PSM, 31 patients were selected from each group. There were significant differences in favorable clinical outcomes on days 7 (67.7% vs. 32.3%, P=0.005) and 14 (71% vs. 41.9%, P=0.045) and the bacteria detection rate on days 7, 14, and the last day. There were also significant differences in days of hospital stay (17 vs. 23 days, P=0.01), antipyretic time (0.5 vs. 7.5 days, P=0.037), and days of antibiotic therapy (14 vs. 23 days, P=0.002). However, there were no significant differences in days of ICU stay, days of MV, and 28-day all-cause mortality. For nephrotoxicity, the NCIA group did not increase the risk of acute kidney injury (16.1% vs. 9.7%, P=0.707), only one patient (3.2%) in the NCIA group developed airway hyperresponsiveness (P=1.000). CONCLUSIONS: For MDR-GNB pneumonia, nebulized colistin sulfate as an adjuvant supportive treatment for intravenous antibiotics maybe can improve clinical efficacy and has high safety.