Background: The role of inhaled colistin as either an adjunctive or substitution for nosocomial pneumonia (NP) caused by carbapenem-resistant organisms (CRO) is highly debated due to conflicting clinical evidence. Given the limitations of intravenous therapy, the optimal administration strategy remains a critical, unresolved question. This study aimed to compare the efficacy and safety of three colistin-based regimens administered via different routes. Methods: In this prospective cohort study, 127 intensive care unit (ICU) patients diagnosed with CRO-related NP and treated with colistin were enrolled. Patients were classified into three groups according to the route of administration: inhalation (IH group), intravenous colistin with adjunctive inhalation (IV+IH group), and intravenous (IV group) therapy. The primary endpoint was clinical efficacy at the end of treatment. Key secondary outcomes included microbiological eradication and nephrotoxicity. Results: Clinical efficacy was achieved in 72.1% of the IH group, 67.4% of the IV+IH group, and 65% of the IV group, with no statistically significant difference among groups ( P =0.786). The IH group demonstrated a significantly higher microbiological eradication rate compared with the IV group ( P =0.004). No significant differences were observed in 28-day all-cause mortality, hospital stay duration, or incidence of acute kidney injury (AKI). Moreover, the development of AKI during treatment was strongly associated with clinical failure, suggesting it may serve as a prognostic marker for poor outcomes. Conclusion: In critically ill patients with CRO-associated NP, inhaled colistin monotherapy provided comparable clinical efficacy to systemic administration. It achieved superior microbiological eradication and showed a favorable safety profile regarding nephrotoxicity, suggesting it represents a viable and potentially safer therapeutic strategy. Keywords: carbapenem-resistant Gram-negative bacteria, colistin, inhalation therapy, intravenous administration, nosocomial pneumonia
Wei et al. (Thu,) studied this question.