Polymyxin B | The Journal of Critical Care Medicine

Aerosolized Plus Intravenous Polymyxin B Versus Colistin in the Treatment of Pandrug-Resistant Klebsiella Pneumonia-mediated Ventilator-Associated Pneumonia: A Retrospective Cohort Study in Bangladesh

Md Jahidul Hasan¹, Chandra Datta Sumi², Shihan Mahmud Redwanul Huq³, Ahmad Mursel Anam⁴, Raihan Rabbani³

1 University of New South Wales, Sydney, NSW, Australia
2 The University of Queensland, Brisbane, Australia
3 Internal Medicine and ICU, Square Hospitals Ltd., Dhaka, Bangladesh.
4 High Dependency Unit, Square Hospitals Ltd., Dhaka, Bangladesh

DOI: 10.2478/jccm-2023-0012

Background: Pandrug-resistant Klebsiella pneumoniae ventilator associated pneumonia (VAP) is associated with high rate of mortality in intensive care unit (ICU) and has been recognized as a difficult-to-treat infection worldwide. Polymyxin B or colistin-based combination therapies are frequently used worldwide though microbial eradication rate is not promising.
Aim: The aim of this study is to compare the clinical outcome of intravenous with aerosolized polymyxin B versus colistin in the treatment of pandrug-resistant K. pneumoniae VAP.
Methods: This retrospective cohort study was conducted on 222 mechanically ventilated patients admitted from May 11, 2019 to October 19, 2020. K. pneumoniae isolates were resistant to all available antibiotics, including polymyxins in culture sensitivity tests. As treatment, polymyxin B and colistin was administered in intravenous and aerosolized form concurrently twice daily in 106 patients and 116 patients in PMB and CLN group, respectively for 14 days. Survival rate, safety, and clinical outcomes were compared among the groups. The Cox proportional-hazard model was performed to calculate hazard ratio (HR) with 95% confidence intervals (CI).
Results: Patients in PMB group showed more microbial eradication than the patients CLN group [68.1% (n=116)/83% (n=106), respectively; P <0.05). The median day of intubation and ICU stay in PMB group was shorter than that in CLN group [10 (IQR: 9-12.25) vs. 14 (IQR: 11-19), P <0.05; 12 (IQR: 10-14) vs. 15 (IQR: 9-18.5), P=0.072, respectively] with reduced 60-day all-cause mortality rate [15% (n=106) vs. 21.55% (n=116)]. Polymyxin B improved survival compared to colistin (multivariate HR: 0.662; 95% CI=0.359- 1.222, P=0.195).
Conclusions: Concurrent administration of intravenous and aerosolized polymyxin B in patients with pandrug-resistant K. pneumoniae-associated VAP revealed better microbial eradication, reduced the length of intubation and ICU stay, and improved survival rate compared to colistin.

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

Md. Jahidul Hasan¹, Raihan Rabbani², Ahmad Mursel Anam³, Ario Santini⁴, Shihan Mahmud Redwanul Huq²

1 Clinical Pharmacy Services, Square Hospitals Ltd., Dhaka, Bangladesh
2 ICU and Internal Medicine, Square Hospitals Ltd., Dhaka, Bangladesh
3 High Dependency Unit (HDU), Square Hospitals Ltd., Dhaka, Bangladesh
4 University of Medicine, Pharmacy, Science and Technology of Targu Mures, Romania

DOI: 10.2478/jccm-2020-0044

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.