Efficacy and Safety of Different Colistin Administration Routes for Nosocomial Pneumonia Caused by Carbapenem-Resistant Organisms: A Single Centre, Open Label, Prospective Cohort Study.

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.