Small animal patient preoperative preparation: a review of common antiseptics, comparison studies, and resistance

This review aims to describe commonly used antiseptics in veterinary medicine including their mechanism of action, spectrum of activity, potential adverse effects, and application techniques. Additionally, it provides a review of the veterinary literature comparing antiseptics, a discussion of effectiveness and efficacy studies, and the potential for increased resistance to biocides and antimicrobials. This review concludes that appropriate selection and use is necessary to prevent the occurrence of surgical site infections, adverse effects, and potential for increasing resistance to antimicrobials. Continued research is needed to fill gaps in the current knowledge such as optimal preparation procedures for various surgical sites, standardization of efficacy and effectiveness testing, and the clinical impact of decreased susceptibility to chlorhexidine and other antiseptics.

Effectiveness of chlorhexidine diacetate and povidone-iodine in antiseptic preparation of the canine external ear canal prior to total ear canal ablation with bulla osteotomy procedure: A preliminary study

OBJECTIVE

This article is a preliminary study to compare the ability of 0.05% chlorhexidine diacetate (CD) and 1% povidone-iodine (PI) solutions to reduce bacterial contamination on the canine external ear canal during initial patient preparation and comparison of the incidence of immediate tissue reactions.

STUDY DESIGN

The study is a multi-institutional, randomised, clinical prospective study.

ANIMALS OR SAMPLE POPULATION

Dogs (n = 19) undergoing total ear canal ablation with bulla osteotomy (TECABO).

METHODS

The external ear of each dog was cleaned with the assigned antiseptic solution. Culture of the ear was performed by standard techniques to semi-quantitatively evaluate bacterial growth and to identify bacterial organisms pre- and post-antiseptic use.

RESULTS

Both antiseptic groups showed a significant reduction in bacterial growth score (BGS) between pre- and post-antiseptic use (CD p = 0.009, PI p = 0.005). There was no difference in the reduction of BGS between CD and PI solutions (p = 0.53). Minor adverse skin reactions occurred in 25% of cases. There was no significant difference in the occurrence of adverse skin reactions between antiseptics (p = 0.63).

CONCLUSION

CD and PI were similarly able to decrease the number of bacteria on the external ear following initial preparation. No difference in the incidence of adverse tissue reactions was found.

CLINICAL SIGNIFICANCE

Properly diluted aqueous formulations of either antiseptic may be used for safe preparation limited to the external ear canal of dogs. Additional studies evaluating outcomes such as duration of bacterial inhibition and incidence of surgical site infections are needed to fully elucidate differences between CD and PI antiseptics prior to TECABO.

Pilot clinical trial: propidium monoazide PCR quantifies reduction of the viable bacterial load after antiseptic preparation of canine oral mucosa

OBJECTIVE

A pilot clinical study to evaluate the use of propidium monoazide PCR (PMA-PCR) in quantifying a reduction of bacterial load after antiseptic use on the canine oral mucosa and skin, comparison of quantitative PCR (qPCR) to PMA-PCR, and comparison of patterns seen between PCR methods and bacterial culture.

ANIMALS

Client-owned dogs (n = 10) undergoing general anesthesia and intravenous catheter placement.

PROCEDURES

The oral mucosa and antebrachial skin of each dog underwent swabs for culture, qPCR, and PMA-PCR before and after antiseptic preparation of each site. Reduction in bacterial load between sampling times was evaluated for each quantification method.

RESULTS

All testing methods found a significant decrease in bacterial load from oral mucosa after antiseptic preparation (culture P = .0020, qPCR P = .0039, PMA-PCR P = .0039). PMA-PCR had a significantly greater reduction of bacterial load after preparation than qPCR (P = .0494). Only culture detected a significant reduction after preparation of the skin (culture P = .0039, qPCR P = .3125, PMA-PCR P = .0703).

CLINICAL RELEVANCE

PMA-PCR was able to quantify a reduction of bacterial load after antiseptic preparation of the high-bacterial load environment, with a pattern similar to that of culture, and was more specific than qPCR for detecting viable bacterial load. The results of this study support the use of PMA-PCR for antiseptic effectiveness studies performed on a high-bacterial load environment, such as canine oral mucosa.

Retrospective multicentric study comparing durations of surgery and anesthesia and likelihoods of short- and long-term complications between cats positioned in sternal or dorsal recumbency for perineal urethrostomy

OBJECTIVE

To compare the durations of surgery and anesthesia and the likelihoods of short- and long-term postoperative complications between cats positioned in sternal recumbency versus dorsal recumbency for perineal urethrostomy (PU).

ANIMALS

247 client-owned cats that underwent PU between January 2004 and December 2015 at 6 veterinary teaching hospitals and 1 private veterinary referral hospital.

PROCEDURES

Medical records were reviewed, and signalment, presenting complaints, previous history of urethral obstruction or PU, diet fed, medications administered, indication for PU, durations of surgery and anesthesia for PU, suture type and size, suture pattern for skin closure, and short- and long-term postoperative complications were recorded. Univariable and multivariable analyses were performed to identify differences in durations of surgery and anesthesia and the likelihoods of short- and long-term complications between cats positioned in sternal recumbency and those positioned in dorsal recumbency.

RESULTS

Patient position was not associated with durations of surgery and anesthesia for PU, even if a concurrent cystotomy was necessary or the patient required repositioning from sternal to dorsal recumbency. Likewise, patient position was not associated with the likelihood of short- and long-term complications.

CONCLUSIONS AND CLINICAL RELEVANCE

The observed lack of differences in outcomes between sternal and dorsal recumbency suggested that logistic considerations and personal preference can continue to guide veterinarians when positioning cats for PU.