Identification and Role of Antimicrobial Susceptibility Patterns of Aerobic Bacteria in the Management of Refractory Chronic Suppurative Otitis Media – A Tertiary Hospital-based Retrospective Study

Objectives: This study identifies aerobic bacteria that cause refractory chronic suppurative otitis media (CSOM) and compares the treatment outcomes of patients treated with antibiotic sensitivity testing (AST) directed antibiotics against those treated with empirical antibiotics. Methods: This retrospective study was conducted at the departments of ENT and Microbiology, AIIMS, Patna. Data were collected from clinical and microbiological laboratory records of patients with complaints of persistent ear discharge from September 2018 to February 2020. Ear discharge samples were cultured and AST data from all patients were examined. Antibiotics were administered to those patients diagnosed with refractory CSOM based on their AST report. Patients were followed up, and their treatment responses were assessed and recorded. Data were analyzed by using IBM SPSS Statistics software Version 20.0. Descriptive analysis was performed and Pearson Chi-square tests were applied and p-values were determined to draw relevant conclusions. Results: A total of 90 patients were examined, of which 70 showed significant bacterial growth and were prescribed AST-directed antibiotics. The remaining 20 patients with insignificant growth were treated empirically. Common microorganisms isolated in our study were P. aeruginosa and S. aureus. Gram-negative and Gram-positive isolates were highly resistant to commonly used fluoroquinolones. Among intravenous (IV) formulations, piperacillin-tazobactam and cefoperazone-sulbactam had the highest sensitivity (>80%) against Gram-negative isolates. There was a statistically significant (p < 0.05) difference in cure rates between patients treated with AST-directed antibiotics (n = 54; 77.1%) and empirical therapy (n = 9; 45%). Route of antibiotic administration (oral versus IV) had no statistically significant effect on treatment outcomes (p > 0.05). Conclusion: In the management of refractory CSOM, AST-directed antibiotic therapy is more effective than empirical treatment. Oral and IV antibiotics were equally effective when combined with aural toileting and ototopical antibiotics. Therefore, when treating such cases, AST-directed antibiotics should always be used to prevent widespread antibiotic resistance caused by injudicious antibiotic use.