Etiological profile, prescribing pattern of antibiotics and clinical outcomes of pneumonia patients in a tertiary care hospital in South India during 5-year period

Background: Pneumonia is one of the most important and serious lower respiratory tract infections, which requires implacable attention. This work aimed to document the causative organisms, antibiotics used, and outcome of pneumonia patients hospitalized in a tertiary care hospital. Materials and Methods: A retrospective study was conducted in the medical departments of a tertiary care teaching hospital for 5 years. Demographic details and clinical details including pertinent laboratory values of patients diagnosed with pneumonia were documented and analyzed using a specifically designed data collection form. Results: The study was conducted on 190 patients. The average age of the study population was 56.7 ± 22.6 years and there was a male preponderance of 111(58.4%) patients. Klebsiella pneumonia was found to be the most frequently isolated pathogen in 12.5% of the sputum culture, followed by Acinetobacter baumannii in 10.22% and Pseudomonas aeruginosa in 9.09%. The most commonly prescribed empirical antibiotics were beta-lactam antibiotics mostly in combination with macrolides for synergy irrespective of Pneumonia Severity Index (PSI) classes. Definitive therapy was classified based on World Health Organization (WHO) Access, Watch, and Reserve (AWaRe) classification of antibiotics, watch category antibiotics were prescribed according to culture report and reserve antibiotics were prescribed only in those cases where watch category antibiotics were resistant. On analyzing PSI of community-acquired pneumonia (176 patients), most of the patients in the study belong to class 4: 61 patients (34.7%) and class 5: 44 patients (25%). For the high-risk patients (PSI class 4 and 5), mortality was approximately 3.8% (4 of 105) and for low-risk patients, there was zero mortality reported within 30 days. Conclusion: Gram-negative bacteria were the major pathogens causing Pneumonia in the study site contradictory to the data from developed countries. Identifications of pathogens and appropriate antibiotic therapy based on PSI score can bring down the duration of hospital stay and mortality of patients with pneumonia.