The treatment of multidrug-resistant Pseudomonas aeruginosa with polymyxin B or E in a patient with the highly pathogenic avian influenza A (H ₅N ₁) infection: A case report and review of the literature

Objective: To study the treatment of the multidrug-resistant Pseudomonas aeruginosa (MDRP) pulmonary infection in patient with the highly pathogenic avian influenza A (H ₅N ₁)infection. Methods: In June 2006, a 31-year old male with avian influenza A (H ₅N ₁) infection complicated with acute respiratory distress syndrome (ARDS) was mechanically ventilated, and then MDRP pulmonary infection was confirmed. The antimicrobial susceptibility tests indicated that the infected MDRP strain in the case was sensitive only to polymyxin B or E. Polymyxin B was subsequently administered intramuscularly or intravenously at a dosage of 40-100mg/day in two divided doses and combined with polymyxin E aerosol therapy with a dosage of 30-50 million IU per day in 3-4 divided doses. The dosage adjustments were done mainly according to the semi-quantitative MDRP analysis, and the overall evaluation of the clinical and laboratory data was considered to decide the course of MDRP antibiotic therapy. Results: The cumulative duration of polymyxin B systemic administration was 33 days and its cumulative dosage was 1,760 mg while that of polymyxin E aerosol administration was 36 days and its cumulative dosage was 1485 million IU. The pulmonary infection in the patient was well controlled with the improvement of clinical outeomes. Counts of Pseudonomas aeruginosa (HH) found in sputum culture were reduced siynificantly (+). Polymyxin was effective in the treatment of MDRP pulmonary infections and had slight side effects. Conclusions: Polymyxin was effective in the management of MDRP pulmonary infections in patient with avian influenza.