Yield of sputum culture and sensitivity in acute exacerbation of chronic obstructive pulmonary disease patients

Background: Acute exacerbations of chronic obstructive pulmonary disease (COPD) are frequently triggered by bacterial infections, leading to increased morbidity, mortality, and healthcare burden. Identification of causative organisms and their antibiotic sensitivity patterns is crucial for guiding empirical therapy, improving patient outcomes, and combating antimicrobial resistance. This study aim to determine the diagnostic yield of sputum culture and sensitivity in acute exacerbation of COPD patients and assess antimicrobial susceptibility patterns to guide targeted antibiotic therapy and promote antimicrobial stewardship. Methods: This cross-sectional study was conducted in the Pulmonology Department, Khyber Teaching Hospital, Peshawar, from December 2024 to June 2025. A total of 135 patients, aged 18–80 years, diagnosed with COPD per GOLD criteria, were enrolled using non-probability consecutive sampling. The WHO sample size calculator (5% margin of error) determined the sample size. Exclusion criteria included recent antibiotic use (within 2 weeks), active tuberculosis, coexisting pulmonary diseases, inability to produce sputum, and immunocompromised states such as HIV/AIDS or immunosuppressive therapy. Results: Of the 135 patients, sputum culture positivity was 71.7%, with all isolates being Gram-negative. The most frequent organisms were Escherichia coli and Citrobacter (17.4% each), followed by Klebsiella (13.8%) and Pseudomonas aeruginosa (8.7%). Acinetobacter and Enterobacter was least common (2.9% each). Highest sensitivities were observed for tigecycline (84.4%), amikacin (78.1%), ertapenem (70.8%), and Meropenem (66.7%), whereas ampicillin, co-amoxiclav, and ceftriaxone showed the highest resistance. Conclusion: Gram-negative organisms, notably E. coli and Citrobacter, predominated in sputum cultures of COPD exacerbation patients. Tigecycline, amikacin, ertapenem, and Meropenem exhibited the best sensitivity profiles, while ampicillin, co-amoxiclav, and ceftriaxone showed marked resistance. Empirical treatment should focus on antibiotics active against these prevalent Gram-negative pathogens to optimize patient outcomes.