Background: Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is a leading cause of intensive care unit (ICU) admission, and bacterial infections are its most common precipitants. The rising burden of antimicrobial resistance (AMR) among respiratory pathogens has rendered empirical antibiotic therapy increasingly ineffective, raising morbidity, mortality, and healthcare costs. Knowledge of local microbial profiles and resistance patterns is critical to improving patient outcomes in ICU settings.

Objective: To assess the bacterial pattern and antibiotic resistance profile among patients with AECOPD admitted to the ICU, and to evaluate the clinical utility of sputum characteristics as bedside predictors of infection and drug resistance.

Methods: A hospital-based observational study was conducted in the Department of Respiratory Medicine, National Institute of Medical Sciences and Research, Jaipur, over 18 months (July 2024 – December 2025). One hundred patients aged ≥40 years with clinico-radiologically confirmed COPD admitted to the ICU with acute exacerbation were enrolled using purposive sampling. Respiratory samples (sputum and endotracheal aspirate [ETA]) were collected aseptically and processed for bacterial culture and antibiotic susceptibility testing as per Clinical and Laboratory Standards Institute (CLSI) guidelines. Statistical analysis was performed using SPSS version 25.

Results: The mean age was 61.8 ± 8.9 years; 70% were male. Smoking history was present in 92% of patients. Bacterial growth was identified in 61% of samples. Gram-negative organisms predominated; the leading isolates were Pseudomonas aeruginosa (16%), Escherichia coli (13%), Staphylococcus aureus (12%), Klebsiella pneumoniae (11%), and Acinetobacter baumannii (5%). Purulent sputum was significantly associated with both culture positivity (p = 0.001) and MDR organisms (p = 0.001). Sputum color correlated significantly with bacterial type (p = 0.001). Resistance was widespread to multiple antibiotic classes; tobramycin and trimethoprim-sulfamethoxazole retained complete susceptibility among tested isolates. Patients with irregular or absent bronchodilator therapy had significantly higher MDR rates (p = 0.01).

Conclusion: ICU-admitted AECOPD patients demonstrate a high burden of gram-negative MDR infections. Sputum purulence and color serve as clinically practical markers of bacterial involvement and resistance risk. Culture-guided antibiotic therapy and institution-specific antibiograms are essential for rational management.

KEYWORDS: AECOPD; COPD Exacerbation; Intensive Care Unit, Bacterial Isolates, Antibiotic Resistance, Multidrug Resistance.