The Susceptibility of MDR-K. Pneumoniae to Polymyxin B Plus its Nebulised Form Versus Polymyxin B Alone in Critically Ill South Asian Patients

Introduction: Critically ill patients in intensive care units are at high risk of dying not only from the severity of their illness but also from secondary causes such as hospital-acquired infections. USA national medical record-data show that approximately 10% of patients on mechanical ventilation in an intensive care unit developed ventilator-associated pneumonia. Polymyxin B has been used intravenously in the treatment of multi-drug resistant gram-negative infections, either as a monotherapy or with other potentially effective antibiotics, and the recent international guidelines have emphasised the use of nebulised polymyxin B together with intravenous polymyxin B to gain the optimum clinical outcome in ventilator-associated pneumonia cases caused by multi-drug resistant gram-negative infections.
Methods: One hundred and seventy-eight patients with ventilator-associated pneumonia due to multi-drug resistant K. pneumoniae were identified during the study period. Following the inclusion and exclusion criteria, 121 patients were enrolled in the study and randomly allocated to two study groups. Group 1 patients were treated with intravenous Polymyxin B plus nebulised polymyxin B (n=64) and Group 2 patients with intravenous Polymyxin B alone (n=57). The study aimed to compare the use of Polymyxin B plus its nebulised form to polymyxin B alone, in the treatment of MDR-K. pneumoniae associated ventilator-associated pneumonia in critically ill patients.
Results: In Group 1, a complete clearance of K. pneumoniae was found in fifty-nine patients (92.1%; n=64) compared to forty patients (70.1%, n=57) in the Group 2 (P<0.003). The average time till extubation was significantly higher in Group 2 compared to Group 1 (P<0.05). The total length-of-stay in the ICU was significantly higher in Group 2 compared to Group 1. (P<0.05). These results support the view that the Polymyxin B dual-route regime may be considered as an appropriate antibiotic therapy, in critically ill South Asian patients with ventilator-associated pneumonia.