Acid-suppressive medication use in acute stroke and hospital-acquired pneumonia

Objective: Pneumonia is a morbid complication of stroke, but evidence-based strategies for its prevention are lacking. Acid-suppressive medications have been associated with increased risk for nosocomial pneumonia in hospitalized patients. It is unclear whether these results can be extrapolated to stroke patients, where other factors strongly modulate pneumonia risk. We investigated the association between acid-suppressive medication and hospital-acquired pneumonia in patients with acute stroke.

Methods: All patients hospitalized with acute ischemic stroke or intracerebral hemorrhage in a large, urban academic medical center in Boston, Massachusetts from June 2000 to June 2010 who were ≥18 years of age and hospitalized for ≥2 days were eligible for inclusion. Acid-suppressive medication use was defined as any pharmacy charge for a proton-pump inhibitor or histamine-2 receptor antagonist. Multivariate logistic regression was used to control for confounders. The main outcome measure was hospital-acquired pneumonia, defined via International Classification of Diseases, Ninth Revision, Clinical Modification codes.

Results: The cohort comprised 1,676 admissions. Acid-suppressive medication was ordered in 1,340 (80%) and hospital-acquired pneumonia occurred in 289 (17.2%). The unadjusted incidence of hospital-acquired pneumonia was higher in the group exposed to acid-suppressive medication compared to those unexposed (20.7% vs 3.6%, odds ratio [OR]=7.0, 95% confidence interval [CI]=3.9-12.7). After adjustment, the OR of hospital-acquired pneumonia in the exposed group was 2.3 (95% CI=1.2-4.6). The association was significant for proton-pump inhibitors (OR=2.7, 95% CI=1.4-5.4), but not for histamine-2 receptor antagonists (OR=1.6, 95% CI=0.8-3.4).

Interpretation: In this large hospital-based cohort of patients presenting with acute stroke, acid-suppressive medication use was associated with increased odds of hospital-acquired pneumonia.