Scientific Poster Session I - Original Research

Original Research
  Saturday, October 12, 2024
  11:30 AM–01:00 PM

Abstract

Introduction: Intraabdominal infections (IAI) remain a significant cause of sepsis in the critically ill. Optimal antimicrobial regimens for IAI are controversial. Although guidelines recommend limiting empiric antibiotics to 4-7 days after source control, antibiotic duration is variable in practice.

Research Question or Hypothesis: This study's aim was to describe antimicrobial prescribing practices for treatment of IAI and assess the need for empiric MRSA coverage in critically ill surgical patients.

Study Design: This single-center, retrospective, cohort study at Vanderbilt University Medical Center included all adults admitted to the Surgical Intensive Care Unit that received antibiotics for an IAI from 6/1/2021-4/30/2023.

Methods: Manual chart review was conducted to confirm an IAI. The primary outcome was antibiotic duration for IAI. Other outcomes included were infections from multi-drug resistant organisms (MDRO) and mortality. Statistical analyses were performed using SPSS. Categorical and continuous data were analyzed using x2 and Mann-Whitney U. Logistic and linear regression were performed to determine risk factors for vancomycin use, mortality, and prolonged antibiotic use.

Results: Of 722 encounters, 334 met inclusion criteria. The median age was 59 years, with 39.5% having septic shock. Most patients received piperacillin-tazobactam (68%), followed by cefepime (36.5%), meropenem (21.9%), and levofloxacin (18.3%). The median antibiotic duration was 8 days (IQR 5-12.25).Vancomycin was used in 71.3% of patients for a median of 4 days (IQR 3-7). Among 130 positive cultures, 8 isolated MRSA, and 67 had MDRO. Those with an infectious disease consult had an average of 5.6 (95% CI 3.2-8.1) more days of antibiotic coverage. Vancomycin was used less frequently with piperacillin-tazobactam (OR 0.34, 95% CI 0.1-0.8). Age (OR 1.05, 95% CI 1.00-1.08) and septic shock (OR 2.8, 95% CI 1.3-6.1) were associated with mortality.

Conclusion: This study provides evidence that broad-spectrum antibiotics for IAI are used for prolonged durations and vancomycin may be over utilized based on the low incidence of MRSA infections.

Presenting Author

Tara Ladsavong PharmD Candidate
Vanderbilt University Medical Center

Authors

Benjamin Brewer PharmD Candidate
Vanderbilt University Medical Center

Kelli Rumbaugh PharmD, BCPS, BCCCP, FCCM
Vanderbilt University Medical Center