Targeting these risk factors with adjunctive therapy may help improve outcomes, say authors of a new study.
Patients with pneumonia and a greater number of specific risk factors were at an increased risk for 30-day mortality than those individuals with no or one risk factor, despite appropriate use of initial antibiotic treatment, according to the results of a study published recently in Lancet Infectious Diseases.
“In terms of the predictors of 30-day mortality in patients who received appropriate initial antibiotics at diagnosis, we clarified five independent factors-hypoalbuminaemia, non-ambulatory status, acidaemia, tachypnoea, and high BUN concentrations,” wrote Yuichiro Shindo, of the Institute for Advanced Research, Nagoya University, Nagoya, Japan, and colleagues. “To our knowledge, this is the first study in which the risk factors in patients who receive appropriate initial antibiotic treatment are explained clearly.”
According to the study, initial antibiotic treatment is a key factor in improved outcomes in patients with pneumonia, and inappropriate initial antibiotic treatment is associated with adverse outcomes. However, studies have shown that positive outcomes are not assured even with appropriate antibiotic therapy.
Therefore, Shino and colleagues conducted a prospective study of 579 patients hospitalized for pneumonia at 10 medical institutions between March 15 and December 22, 2010 to identify risk factors that might be associated with mortality in patients given first-line antibiotic therapy. They used 30-day all-cause mortality as their primary endpoint.
The overall rate of 30-day mortality was 11% in those patients considered to have received appropriate initial antibiotic treatment compared with 17% in those given inappropriate initial antibiotic treatment.
Specifically, the researchers were able to identify several risk factors that increased the risk for 30-day all-cause mortality despite initial antibiotic therapy:
âº Albumin concentration <30 mg/L (adjusted OR=3.39, 95% CI 1·83–6·28),
âº Non-ambulatory status (adjusted OR=3.34; 95% CI, 1·84–6·05),
âº pH <7·35 (adjusted OR=3.13; 95% CI, 1·52–6·42),
âº Respiration rate of at least 30 breaths/min (adjusted OR=2.33; 95% CI, 1·28–4·24), and
âº Blood urea nitrogen of at least 7·14 mmol/L (adjusted OR=2.20; 95% CI, 1·13–4·30)
The risk for mortality increased with an increasing number of risk factors. The 30-day mortality was 1% in patients with no risk factors or one risk factor, compared with 17% in patients with two risk factors, 22% in those with three, and 44% in patients with four or five risk factors.
“For patients with two or more risk factors, comprehensive treatment including appropriate initial antibiotics and other adjunctive therapies would be needed to improve outcomes,” the researchers wrote. “For example, treatment could include the following traditional strategies: appropriate respiratory management, fluid resuscitation, and nutritional care for critically ill patients; oral care and aspiration prevention to reduce the incidence of secondary pneumonia; and physical therapy to interrupt the progression of muscle weakness.”
Shindo Y, Ito R, Kobayashi D, et al. Risk factors for 30-day mortality in patients with pneumonia who received appropriate initial antibiotics: an observational cohort study. Lancet Infect Dis. 2015 July 2. Epub ahead of print.