Prevalence of Causative Bacteria, Therapeutic Choices of Antimicrobials and Clinical Outcomes among Patients with Hospital-Acquired Pneumonia and Ventilator-Associated Pneumonia in A General Hospital

Abstract

Objectives: To assess the prevalence of etiologic bacteria of hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP), the antibiotic susceptibility of the isolated pathogens and the prescribed antimicrobial therapy. Relationship between select factors and clinical outcomes was tested. Methods: This retrospective study included HAP or VAP patients admitted to Hua-hin Hospital, a general hospital, from January to December 2013. Patients aged 18 or older and diagnosed with HAP or VAP were included. The bacteria isolated from HAP or VAP patients were listed as etiologic pathogens and the clinical outcomes were classified as treatment failure and 30-day mortality rate. Results: Of the 106 patients recruited, their median age was 72 years (range: 18 - 95 years). It was found that 56.6% of 106 patients were male, 81.1% had comorbid diseases and 27.4% were admitted to the intensive care unit. With 15 patients with negative sputum culture, 91 patients contributed 155 isolated organisms. Of the 46 HAP cases, A. baumannii (23.8%), P. aeruginosa (20.6%) and K. pneumoniae (17.5%) were the most frequently found isolated organisms; while A. baumannii (32.6%), P. aeruginosa (18.5%) and S. aureus (22.8%) were the most frequently identified among 60 VAP cases. Imipenem and meropenem were a good option for K. pneumoniae; while vancomycin remained the best drug against methicillin-resistant S. aureus. Of the 106 cases, the crude 30-day mortality rate and treatment failure were 17.9% and 34%, respectively. The appropriate antimicrobial treatment and multi-drug resistant A. baumannii were the two factors significantly associated with treatment failure in the opposite directions, with odds ratios of 0.126 and 3.624, respectively. Conclusion: Our findings illustrated the pattern of causative pathogens in a general hospital that seemed to have the same trouble as in a larger-sized hospital. The appropriate antimicrobial treatment and multi-drug resistant A. baumannii were related to the unfavorable outcome. Keywords: causative pathogens, clinical outcome, pneumonia