Retrospective assessment of perioperative antimicrobial use for elective arthroscopy in horses

Abstract

Objective To describe perioperative antimicrobial use in horses undergoing elective arthroscopy. Study design. Retrospective study. Sample population. Horses that underwent elective arthroscopy at one institution between July 2016 and May 2018, excluding those with a suspected infectious orthopedic disease or with a comorbidity that may have impacted prophylactic antimicrobial use decisions. Methods Medical records were reviewed to evaluate preoperative, intraoperative, and postoperative antimicrobial drug selection, dose, and timing. Associations between body weight and underdosing were evaluated by using analysis of variance, χ2 test was used for categorical comparisons, and least squares fit was used to evaluate factors associated with duration of postoperative antimicrobials. Results Among 150 horses, 149 (99.3%) received systemic preoperative antimicrobials. Only 53 (40.2%) horses were administered doses within 60 minutes of surgical incision. First incision was performed more than two half‐lives after administration of sodium penicillin in 46 of 131 (35.1%) horses but in only 1 of 106 (0.8%) horses that received trimethoprim‐sulfadoxine. Body weight was associated with underdosing for penicillin (P = .0075) and trimethoprim‐sulfadoxine (P = .002) but not gentamicin (P = .92). Twenty‐six (17%) horses received one postoperative antimicrobial dose, while antimicrobials were continued in hospital for a mean of 22.3 ± 4.4 hours after surgery in the other 123 horses. Among the 149 discharged horses, 115 (77.2%) were prescribed antimicrobials after discharge (range, 3‐10 days; median, 3 days, interquartile range, 0 days). Conclusion Deviations from common recommendations were apparent and provide evidence for the requirement to develop interventions to optimize perioperative prophylaxis. Clinical significance Perioperative antimicrobial use practices should be regularly assessed to provide a benchmark and identify areas for intervention.

Use of Clinical Audits to Evaluate Timing of Preoperative Antimicrobials in Equine Surgery at a Veterinary Teaching Hospital

“…In audit 1, 37.5% of the arthroscopies met the <60-min threshold for tAB-INC. However, this percentage increases to 72% if only single joint arthroscopies are considered, which compares favorably to the study by Muntwyler et al where primarily one-joint arthroscopies (66.3% of cases) were included (10). This also highlights the critical contribution of tPREP to tAB-INC as the number of operated joints increases.…”

“…However, our results for tAB-INC are approximately half of that previously reported for arthroscopies (142 min) by a different institution, with different hospital policies (9). A retrospective study conducted by the same institution reported an improvement in their rate of arthroscopies achieving a tAB-INC < 60 min; improving from 6.3 to 40.2% (10). It is possible that the hospital policy regarding antimicrobial prophylaxis was modified after the first study, but the factors that contributed to this improvement were not described in the second study.…”

“…In contrast to human surgery, antimicrobial prophylaxis is routinely used in clean procedures in horses and this practice has received limited research attention and remains controversial (17). The goal of this study, as with previous work, was to evaluate and improve current practice, based upon the degree of adherence to extrapolated human guidelines (5,9,10), and not to assess antimicrobial efficacy. Previous studies reveal a variation in antimicrobial use between institutions as well as differences between intended and actual antimicrobial administration within institutions (5,9,10).…”

“…Additionally, guidelines suggest administration of antimicrobials with a short half-life, such as sodium penicillin, within 60 min of surgical incision to achieve therapeutic tissue concentrations at the time of surgery (1,2,(4)(5)(6)(7)(8). However, previous equine studies have shown that meeting this target is difficult and influenced by hospital policies (5,9,10).…”

Highlights of recent clinically relevant papers

“…This retrospective study by Noah Muntwyler and colleagues in Canada aimed to describe perioperative antimicrobial use in horses undergoing elective arthroscopy.…”