1300. Comparison of Narrow vs. Broad Spectrum Antibiotics for Treatment of Community-acquired Aspiration Pneumonia

Abstract

Abstract Background Aspiration pneumonia (aspPNA) accounts for 5-15% of pneumonia admissions. Despite the absence of risk factors for organisms such as methicillin-resistant S. aureus (MRSA) or Pseudomonas aeruginosa (PsA), broad-spectrum (BS) antibiotics active against these pathogens are frequently prescribed. We compared outcomes of patients receiving narrow-spectrum (NS) versus BS antibiotics for aspPNA. Methods This is a retrospective cohort study of hospitalized patients started on antibiotics for aspPNA upon admission from 1/1/2019 to 12/31/2019. The BS cohort included patients prescribed antibiotics with activity against PsA or MRSA and were on BS antibiotics for > 50% duration of therapy regardless of de-escalation. The primary endpoint was clinical response, defined as resolved, improved, no change, or worsened. Secondary endpoints included 30-day all-cause mortality, duration of therapy, 30-day C. difficile infection, and length of stay. Outcomes were assessed using logistic regression with antibiotic group as a fixed effect, and all analyses were conducted using R v. 4.0.3. Results A total of N=95 patients were included in the study, 35 in the NS and 60 in the BS groups. Clinical response was similar in distribution between groups (p > 0.3). 30-day all-cause mortality was lower in the NS (11.4%) as compared to the BS group (33.3%) (OR 0.26; 95% CI 0.09- 0.81; p < 0.04). There were no differences for the secondary endpoints including median duration of therapy (4 [IQR 2.5] days vs. 6 [IQR 6] days, p> 0.2), 30-day C. difficile infection (0% vs 6.7%, p > 0.3), and median length of stay (6 [IQR 5] days vs. 7 [IQR 8.5] days, p > 0.2) in NS vs. BS groups, respectively. A positive blood or respiratory culture was isolated in 37% (35/95) patients. Enteric organisms were the most prevalent bacteria isolated (20%), followed by methicillin susceptible S. aureus (8%), and Streptococcus spp (7%). MRSA and PsA were detected in 2% and 3% of patients, respectively. Conclusion There is no difference in efficacy between NS and BS antibiotics for aspPNA. Microbiologic data confirm the low incidence of PsA or MRSA causing aspPNA despite high empiric prescribing of antibiotics active against these pathogens. These results support the ongoing need for targeted antibiotic stewardship initiatives for aspPNA. Disclosures All Authors: No reported disclosures