Community-Acquired Pneumonia (CAP) Therapy Is Insufficient for Most Patients With Culture-Positive Healthcare-Associated Pneumonia (HCAP)

Abstract

Background. Guidelines for HCAP recommend broad spectrum coverage with multiple antibiotics. Some question whether all HCAP patients are at risk for resistant organisms; in practice many receive antibiotics consistent with community-acquired pneumonia (CAP) guidelines. We examined antibiotic resistance among HCAP patients in a contemporary national sample. Methods. This retrospective cohort study assessed adult patients admitted with HCAP from 2010 to 2015 to 177 US hospitals that participate in Premier, providing administrative and microbacteriological data. HCAP was defined as having prior hospitalization within 90 days, hemodialysis, admission from a skilled nursing facility (SNF), or immune suppression. Patients with identical Gram negative organisms in blood and urine were excluded. Cultures were obtained in the first 5 hospital days. Resistance to empiric CAP therapy was defined as resistance to a respiratory quinolone, or a 3rd-generation cephalosporin and macrolide. Results. A total of 48,440 patients had HCAP. Overall mean age was 69 ± 15 (range 18-89); 49% were male, and 98% had ≥1 culture, including blood (96%) and respiratory (64%) specimens. Of these, 9354 (19%) had a positive culture; 7391 had culturesensitivity available for all CAP antibiotics: 5383 (73%) were resistant to either a quinolone (47.0%) or a macrolide/3rd-generation cephalosporin (66.6%); 41% were resistant to all three. Of patients with resistant pathogens, 73% had Gram-negatives, most commonly P. aeruginosa, E. coli and K. pneumoniae and 35% had Gram-positives, most commonly S. aureus. Except for K. pneumoniae and P. aeruginosa, respiratory cultures yielded more resistant pathogens compared to blood cultures (80% versus 54.1%; p < 0.001). Resistance to CAP therapy was most common with recent hospitalization (85%) and transfer from SNF (84%); less common for patients on hemodialysis (69%). Patients with resistance to CAP antibiotics had increased length of stay and cost and higher unadjusted mortality. From 2010 to 2015, the proportion of patients resistant to CAP therapy decreased from 75% to 66% (p for trend 0.02). Conclusion. In a large US sample, most HCAP pathogens were resistant to either a quinolone or a macrolide/cephalosporin. CAP therapy appears insufficient for most HCAP patients.