NEW YORK (Reuters Health) – Starting antibiotics within the first two days of hospitalization for chronic obstructive pulmonary disease (COPD) significantly improved outcomes in a large cohort study – supporting the advice of published guidelines, according to a new report.

“These findings confirm our belief that antibiotics are helpful in severe COPD exacerbations, even though that belief was founded on some very small studies,” lead author Dr. Michael B. Rothberg, of Baystate Medical Center in Springfield, Massachusetts, told Reuters Health by e-mail. “In contrast, our study contained almost 85,000 hospitalized patients, so we were able to detect differences in rare outcomes like mortality.

Over a 2-year period (January 2006 through December 2007), 84,621 patients aged 40 and older were hospitalized with acute COPD exacerbation at 413 U.S. acute care hospitals. According to Dr. Rothberg and his colleagues, 79% of them received at least 2 consecutive days of antibiotic treatment starting on day 1 or 2, most commonly a quinolone (60%), a cephalosporin (37%), or a macrolide (38%).

Compared to patients who either did not receive antibiotics or received them later in their hospital stay, the early antibiotics group had lower rates of mechanical ventilation after the second hospital day (1.07% vs 1.80%), lower inpatient mortality (1.04% vs 1.59%%), and lower 30-day readmission rates for acute COPD flare up (7.91% vs 8.79%). Antibiotic treatment did not make a difference in terms of length of hospital stay, but it did lower costs.

Antibiotic therapy in patients hospitalized with acute COPD exacerbation was associated with a 13% decrease in the risk of treatment failure — a composite of these outcomes.

“We tried to find patients that would not benefit from antibiotics based on several factors, including how likely they were to fail treatment, and whether their doctor ordered a sputum test or a blood gas, but we couldn’t find one,” Dr. Rothberg said.

Furthermore, “we found little evidence of harm,” the researchers report in the May 26th Journal of the American Medical Association.

Dr. Rothberg told Reuters Health that patients who received antibiotics were “slightly more likely” to be readmitted with Clostridium difficile diarrhea, “but this was rare (about 1 in 1000 patients) and the mortality benefit was much greater than the risk of severe diarrhea.” There was no difference in the number of allergic reactions between patients who did and did not receive antibiotics.

Current COPD treatment guidelines recommend antibiotics only for patients with increased sputum production or purulent sputum. “That is too bad,” Dr. Rothberg said, “because we believe that only about half of COPD exacerbations are caused by infections, so probably a lot of patients don’t need antibiotics.  We just couldn’t tell which ones do and which ones don’t.”

“There are some exciting studies going on now trying to tell who has a bacterial infection, but until we have more definitive answers, our results suggest that all hospitalized patients with COPD exacerbations should get antibiotics,” he said.

Since only about 80% of patients in the current study did receive antibiotics, “we definitely have room for improvement,” he said.

Reference:

JAMA 2010;303:2035-2042.