Clinical Outcomes of Aerosolized Versus Intravenous Colistin in Ventilator-Associated Pneumonia Caused by Multidrug-Resistant Gram-Negative Bacteria

Background: Ventilator-associated pneumonia (VAP) caused by multidrug-resistant (MDR) Gram-negative bacteria has presented significant treatment challenges in critical care. While intravenous colistin is commonly used, its nephrotoxicity and limited lung penetration raise concerns. This study aimed to compare the clinical efficacy and safety of aerosolized versus intravenous colistin in patients with VAP. Methods: The study included 60 adult patients diagnosed with VAP caused by colistin-sensitive MDR Gram-negative bacteria. Treatment decisions (aerosolized or intravenous colistin) were made by attending physicians based on clinical judgment (n = 30 per each group). The primary outcome was clinical success; secondary outcomes included time to defervescence, Clinical Pulmonary Infection Score changes, and adverse events. Results: Clinical success was achieved in 80.0% of patients in the aerosolized group compared with 70.0% in the intravenous group (P = 0.38). The time to defervescence was significantly shorter in the aerosolized group (3.0 ± 1.2 days) than in the intravenous group (5.0 ± 1.7 days; P = 0.002). Nephrotoxicity occurred in 13.3% of patients receiving aerosolized colistin and in 23.3% of those receiving intravenous colistin (odds ratio (OR) 0.51; 95% confidence interval (95% CI) 0.13-2.03; P = 0.19). Microbiological clearance was observed in 66.7% of the aerosolized group and 56.7% of the intravenous group (P = 0.44). Intensive care unit mortality was 16.7% in the aerosolized group and 23.3% in the intravenous group (P = 0.52). Conclusion: Aerosolized colistin was feasible and generally well tolerated; however, these findings should be interpreted as descriptive and hypothesis-generating, and further studies are needed to confirm their clinical relevance.