Antimicrobial Use in Horses Undergoing Colic Surgery

Abstract

Background: Recommendations for antimicrobial prophylaxis for surgery are well-described in human medicine, but information is limited for veterinary practice.Objective: To characterize antimicrobial use in horses undergoing emergency colic surgery. Animals: A total of 761 horses undergoing emergency colic surgery (2001)(2002)(2003)(2004)(2005)(2006)(2007). Methods: Retrospective case review. Antimicrobial dose and timing, surgical description, and duration of treatment were collected from medical records. Associations between antimicrobial use and the occurrence of fever, incisional inflammation or infection, catheter-associated complications, or Salmonella shedding during hospitalization were analyzed using rank-sum methods and logistic regression.Results: A total of 511 (67.2%) horses received an inappropriate amount of drug preoperatively. Median time from preoperative dose to incision was 70 (IQR 55-90) minutes; median total surgery time was 110 (IQR 80-160) minutes. Seventy-three horses were euthanized under anesthesia because of poor prognosis. Of 688 horses, 438 should have been redosed intraoperatively based on the duration of surgery. Only 8 (1.8%) horses were redosed correctly. Horses remained on perioperative antimicrobials a median of 3 (IQR 2-4.5) days. Antimicrobial therapy was reinstituted in 193 (28.9%) horses, and median days of total treatment were 3.8 (IQR 2-6). Signs that led to reinstituting therapy were fever (OR 3.13, P = .001) and incisional inflammation/infection (OR 2.95, P = .001). Horses in which treatment was reinstituted had 2.3 greater odds of shedding Salmonella (P = .003). Increased surgical time was associated with longer duration of antimicrobial therapy (OR 1.02, P = .001).Conclusions and Clinical Relevance: Despite published recommendations regarding antimicrobial prophylaxis, compliance is poor; improvement might reduce postoperative complications.

Antimicrobial prescribing practices by Swiss, German and Austrian equine practitioners

“…The authors’ data are in agreement with data from other countries, supporting that similar concerns regarding antimicrobial prescribing practices are present in North America and Europe (Weese and Sabino 2005, Weese and Cruz 2009, Dallap Schaer and others 2012, Hughes and others 2013, De Briyne and others 2014). The frequency of selection of a CIA (European Medicines Agency 2014) was similar to a European-wide survey (De Briyne and others 2014).…”

“…Extending the perioperative treatment is controversial as no beneficial effect of prolonged duration compared with single dose or no prophylactic administration could be shown (Borg and Carmalt 2013, Freeman and others 2012). This study and others indicate that excessive use of surgical antimicrobial prophylaxis is common in equine practice (Weese and Cruz 2009, Dallap Schaer and others 2012). …”

Incisional infections associated with ventral midline celiotomy in horses

“…Horses receive perioperative antimicrobial therapy during emergency exploratory celiotomy due to the likelihood of the procedure being clean contaminated or contaminated, as well as the risk of pneumonia in horses that are anesthetized or shipped long distances to reach the hospital 67,68 . Suggested guidelines for antimicrobial prophylaxis in horses undergoing clean‐contaminated procedures include choosing a broad‐spectrum antimicrobial of lower generation (to minimize development of bacterial resistance), administration within 30–60 min of the initial incision, and re‐dosing intraoperatively if surgery exceeds 2 half‐lives of the preoperative dose 69 . A retrospective study at one institution reported frequent improper use of antimicrobial prophylaxis including inaccurate dosing, administration >60 min prior to surgery, and lack of re‐dosing when surgery time exceeded 2 half‐lives of the drug 69 .…”

“…Suggested guidelines for antimicrobial prophylaxis in horses undergoing clean‐contaminated procedures include choosing a broad‐spectrum antimicrobial of lower generation (to minimize development of bacterial resistance), administration within 30–60 min of the initial incision, and re‐dosing intraoperatively if surgery exceeds 2 half‐lives of the preoperative dose 69 . A retrospective study at one institution reported frequent improper use of antimicrobial prophylaxis including inaccurate dosing, administration >60 min prior to surgery, and lack of re‐dosing when surgery time exceeded 2 half‐lives of the drug 69 . This study reported a surgical site infection rate of 15.6% and suggested that some postoperative complications including surgical site infections may be reduced by using appropriate antimicrobial protocols 69 .…”

“…A retrospective study at one institution reported frequent improper use of antimicrobial prophylaxis including inaccurate dosing, administration >60 min prior to surgery, and lack of re‐dosing when surgery time exceeded 2 half‐lives of the drug 69 . This study reported a surgical site infection rate of 15.6% and suggested that some postoperative complications including surgical site infections may be reduced by using appropriate antimicrobial protocols 69 . Antimicrobial drug re‐dosing in this study was related to potassium penicillin, 69 and 92% of isolates from surgical site infections in a different cohort of horses after colic surgery were resistant to penicillin 36 .…”