Antimicrobial management of acute exacerbation of chronic airflow limitation

Antibiotics are frequently administered for exacerbations of chronic obstructive pulmonary disease and asthma, yet their role remains unclear. We prospectively audited the antimicrobial management of 167 patients aged >50 years hospitalized for exacerbations of chronic airflow limitation. Antibiotics were commenced on admission for 151 (90%) patients (oral 52%, intravenous 38%), including 17/23 (74%) with no evidence of fever, purulent sputum, leucocytosis or inflammatory chest X-ray changes. The mean number of different antibiotics prescribed was 1.8 (range 0-6); a wide range of antibiotics and antibiotic combinations were used. Sputum samples were sent for microbiological examination in 101 (61%) patients. Sputum culture was positive in 34, but only 11 (7% of the total) had amoxycillin-resistant organisms in their sputum. Seventeen patients (10%) developed diarrhoea while in hospital. Under logistic regression analysis, total number of antibiotics prescribed (p<0.0001) and age (p=0.0062) were the two factors associated with hospital-acquired diarrhoea. Only 34% of patients had received an influenza vaccination in the winter of the study, and 10% a pneumococcal vaccination within the last 5 years. In routine clinical practice, aggressive antibiotic therapy was frequently administered to patients admitted with chronic airflow limitation, despite limited clinical, radiological and microbial indications. Excessive use of antibiotics has important implications, including morbidity (antibiotic-associated diarrhoea), cost and the potential for increased microbial antibiotic resistance. A minority of patients with chronic airflow limitation are being vaccinated against influenza and Pneumococcus.