Surgical hand antisepsis in veterinary practice: Evaluation of soap scrubs and alcohol based rub techniques

Comparison of chlorhexidine and alcohol-based antisepsis on the paralumbar fossa in cattle

OBJECTIVE

To determine skin reaction, post-treatment reduction (immediate effect), and 1 hour post-treatment reduction (sustained effect) of aerobic bacterial colony forming units (CFU) following three antiseptic protocols in cattle.

STUDY DESIGN

Prospective, randomized experimental study.

ANIMALS

Eighteen cows.

METHODS

Three sites in each paralumbar fossa were clipped and randomly assigned to one of three treatment groups: 5 minute 4% chlorhexidine gluconate scrub (CHG); 90 second 80% ethanol scrub (ET); 90 second 70% isopropyl alcohol scrub (IPA). All sites were monitored at all sampling time points and at 24 hours following treatment for adverse skin reaction. Samples were collected pre-, immediately post-, and 1 hour post-treatment and plated in duplicate. Bacterial counts were shifted to eliminate zeroes, log₁₀ transformed, and averaged. ANOVA was used to compare differences in mean reduction in log₁₀ CFU/ml between groups.

RESULTS

Reduction in log10CFU/ml was more pronounced immediately after application of IPA (p = .001) and ET (p = .001) than CHG. This reduction was better sustained after preparation with CHG than ET (p = .005) but not IPA. Immediate and sustained reductions in bacterial loads did not differ after application of IPA or ET. No adverse skin reactions were noted.

CONCLUSIONS

Skin preparation with alcohol-based antiseptics was well tolerated and improved immediate bacterial reduction compared to CHG. This reduction was better sustained 1 hour after application of CHG than ET, but no difference was detected between CHG and IPA.

CLINICAL RELEVANCE

Lack of adverse skin reaction and performance provide evidence to support skin preparation with alcohol-based antiseptics in cattle.

Comparative antimicrobial efficacy of 4 surgical hand-preparation procedures prior to application of an alcohol-based hand rub in veterinary students

OBJECTIVE

To determine the influence of skin preparations before application of an alcohol-based hand rub (ABHR) on bacterial counts before and after elective surgery.

STUDY DESIGN

Clinical prospective study.

SAMPLE POPULATION

Veterinary students (n = 103) performing ovariohysterectomies on 140 dogs.

METHODS

Participants were randomly assigned to 1 initial surgical preparation on the day of surgery: A - hand preparation with medicated solution (4% w/v chlorhexidine bigluconate followed by an ABHR; B - application of a medication solution (benzalkonium chloride 0.1%-1% and polymeric biguanide hydrochloride 0.01%-0.1%) followed by an ABHR; C - nonmedicated pH-neutral soap hand wash followed by ABHR, and D - direct application of an ABHR. Samples were taken by pressing the distal finger tips to an agar plate before the hand preparation, after the hand preparation (n = 3), after ABHR application, and 120 minutes later. Colony-forming units (CFUs) for samples were determined. Total log CFU and CFU log10 reduction were calculated and used for comparison with P < .05.

RESULTS

Two hours after surgery commenced, the participants of groups that performed a hand preparation had lower total CFUs than those that did not perform a hand preparation (P = .001). In particular, the number of CFUs was lower when ABHR was performed after application of pHN compared to direct ABHR (P = .001).

CONCLUSION

In this population, performing a hand preparation with pHN prior to applying an ABHR had better antimicrobial effect for the duration of surgery than not performing a hand preparation.

CLINICAL SIGNIFICANCE

Surgeons should wash their hands prior to ABHR before starting their first surgery of the day, even when hands appear clean.

Pre-surgical hand preparation in veterinary practice

The objective of this paper is to review the evidence for different methods of surgical hand preparation applicable to veterinary practice. Surgical hand preparation is an essential step in performing surgery as a veterinarian. Recommended protocols and products for surgical hand preparation have varied since its inception in the late 1800s. Many factors must be considered when assessing the efficacy, safety, and users' compliance with any available product. Traditional scrub methods employing chlorhexidine gluconate or povidone-iodine have been compared to alcohol-based rub protocols with respect to immediate and prolonged efficacy, safety, compliance, requirements for theatre furniture, cost and water usage. Although much of the comparative data has been generated in human medical facilities, extrapolation of the data to veterinary surgery is appropriate. Considerations for veterinary practice are specifically discussed. Overall, the benefits of alcohol-based rubs indicate that this should be the preferred method of pre-surgical hand preparation for veterinarians in all types of practice.

Influence of intraoperative closed glove exchange on glove contamination during clean soft tissue surgeries

OBJECTIVES

To determine the influence of intraoperative glove exchange on glove contamination during clean soft tissue surgery.

STUDY DESIGN

Prospective clinical study.

SAMPLE POPULATION

Two hundred pairs of gloves and gowns from 50 clean soft tissue surgeries.

METHODS

Gloves and gown cuffs were cultured from the primary surgeon and first assistant using a standardized protocol. Cultures were taken from outer surface of both gown cuffs prior to surgery and after gloves were removed at the end of surgery; gloves were cultured prior to surgery, at end of surgery and after a new pair was donned after closed glove exchange. Cultures were evaluated for colony-forming units after 72 h of inoculation.

RESULTS

Bacterial contamination was documented in 41 of the 50 surgeries (82%). The most common species cultured was Streptocococcus spp. There was no difference (p = .719) in the bacterial contamination rate of gown cuffs prior to surgery (10%; 20/200) compared to after surgery (9.5%; 19/200). The bacterial contamination rate for gloves was 10.5% (21/200) prior to surgery, 19.5% (39/196) after surgery, and 11% (22/200) after regloving. Gloves cultured following surgery were significantly more contaminated than gloves cultured preoperatively (p = .010) or gloves cultured following regloving (p = .018).

CONCLUSION

Glove exchange did not increase bacterial contamination of gloves during the clean soft tissue surgeries tested here.

CLINICAL SIGNIFICANCE

The outside of the gown cuff does not seem to represent a major source of contamination during clean procedures. This study does not provide evidence to support a change in current practices for intraoperative closed glove exchange.

Perforations of tri-layer nitrile-latex and natural rubber latex gloves during ex-vivo equine intestinal anastomoses

OBJECTIVE

To compare perforation rates between tri-layer nitrile-latex and natural rubber latex surgical gloves after single-layer end-to-end jejunojejunal anastomoses in equine cadavers.

STUDY DESIGN

Prospective randomized ex-vivo study.

SAMPLE POPULATION

Pairs of surgical gloves (n = 46) worn during jejunojejunal anastomoses.

METHODS

Tri-layer nitrile-latex and rubber latex pairs of gloves were equally but randomly allocated to a right-handed surgeon performing 46 single-layer end-to-end jejunojejunal anastomoses on cadaveric material. Number and location of perforations were determined with the water leak test after each procedure. Ten unused pairs of both glove types were tested as controls.

RESULTS

At least one perforation occurred in 41% (19/46) of the pairs of gloves. Glove perforations were present in 22% (5/23; 95% CI: 9-42) of tri-layer glove pairs and 61% (14/23; 95% CI: 41-78) of the rubber glove pairs. The odds of glove perforation were 5.6 times (p = .009, 95% CI: 1.5-20.5) lower when tri-layer rather than rubber gloves were used. The duration of procedure did not affect the risk of glove perforation (p = .679). No perforations were observed in the unused gloves.

CONCLUSION

Perforations were less common when the surgeon wore tri-layer nitrile-latex gloves rather than to the natural rubber latex gloves tested in this study.

CLINICAL RELEVANCE

Tri-layer nitrile-latex gloves were more resistant to perforations in experimental settings; further studies may confirm that they are also superior in a clinical setting.

Using Waterless Alcohol-based Antiseptic for Skin Preparation and Active Thermal Support in Laboratory Rats

Rodents are frequently used for models that require surgical procedures. At our institution, laboratory rats are increasingly preferred for investigations of neurologic disorders, cardiovascular interventions, and assessment and treatment of addictive and depressive behaviors. For these types of studies, surgical preparations of the head and neck areas are necessary for catheterization and instrumentation. Based upon our former work in laboratory mice, we sought to improve rat surgery outcomes and confirm the efficacy of a waterless alcohol-based (WAB) antiseptic for skin disinfection prior to incision. In addition, we wanted to investigate whether active warming efforts improved perioperative body temperatures for rats to aid in return to consciousness. Prior to cranial surgical incision and placement in stereotactic equipment, rats were assessed after skin preparation with WAB and after thermal interventions, including prewarming cages for 30 min before anesthesia and delivery of warmed fluid (NaCl) supplementation. Core temperatures were recorded and aerobic culture swabs collected from surgical sites at multiple time points. As previously shown in mice, bacterial counts in rats were effectively diminished by WAB agents. Assessment of intraoperative body temperature trajectories did not identify appreciable differences between control rats and rats that were exposed to prewarming or warmed fluid supplementation or both. However, heavier male rats recovered more rapidly from isoflurane anesthesia than did lighter male and female rats. Although these thermal support measures did not significantly improve anesthetic recovery times in rats, animals warmed for 30 min trended toward a faster return to righting reflex after exposure to isoflurane. These findings confirm that WAB antiseptic is an acceptable option for skin preparation in rats and suggest that continued evaluation of thermal interventions remains of interest for improved outcomes in rat surgery.

Surgical hand preparation in an equine hospital: Comparison of general practice with a standardised protocol and characterisation of the methicillin-resistant Staphylococcus aureus recovered

Presurgical hand asepsis is part of the daily routine in veterinary medicine. Nevertheless, basic knowledge seems to be low, even among specialised veterinary surgeons. The major objectives of our study were to assess current habits for presurgical hand preparation (phase 1) among personnel in a veterinary hospital and their effectiveness in reducing bacteria from hands in comparison to a standardised protocol (phase 2). Assessment of individual habits focused on time for hand washing and disinfection, the amount of disinfectant used, and the usage of brushes. The standardised protocol defined hand washing for 1 min with liquid neutral soap without brushing and disinfection for 3 min. All participants (2 surgeons, 8 clinic members, 32 students) used Sterillium®. Total bacterial counts were determined before and after hand washing, after disinfection, and after surgery. Hands were immersed in 100 ml sterile sampling fluid for 1 min and samples were inoculated onto Columbia sheep blood agar using the spread-plate method. Bacterial colonies were manually counted. Glove perforation test was carried out at the end of the surgical procedure. Differences in the reduction of relative bacterial numbers between current habits and the standardised protocol were investigated using Mann-Whitney-Test. The relative increase in bacterial numbers as a function of operation time (≤60 min, >60 min) and glove perforation as well as the interaction of both was investigated by using ANOVA. Forty-six and 41 preparations were carried out during phase 1 and phase 2, respectively. Individual habits differed distinctly with regard to time (up to 8 min) and amount of disinfectant (up to 48 ml) used both between participants and between various applications of a respective participant. Comparison of current habits and the standardised protocol revealed that the duration of hand washing had no significant effect on reducing bacteria. Contrary, the reduction in bacterial numbers after disinfection by the standardised protocol was significantly higher (p<0.001) compared to routine every-day practice. With regard to disinfection efficacy, the standardised protocol completely eliminated individual effects. The mean reduction in phase 1 was 90.72% (LR = 3.23; right hand) and 89.97% (LR = 3.28; left hand) compared to 98.85% (LR = 3.29; right hand) and 98.92% (LR = 3.47; left hand) in phase 2. Eight participants (19%) carried MRSA (spa type t011, CC398) which is well established as a nosocomial pathogen in veterinary clinics. The isolates could further be assigned to a subpopulation which is particularly associated with equine clinics (mainly t011, ST398, gentamicin-resistant). Glove perforation occurred in 54% (surgeons) and 17% (assistants) of gloves, respectively, with a higher number in long-term invasive procedures. Overall, bacterial numbers on hands mainly increased over time, especially when glove perforation occurred. This was most distinct for glove perforations on the left hand and with longer operating times. Our results demonstrate that standardised protocols highly improve the efficacy of hand asepsis measures. Hence, guiding standardised protocols should be prerequisite to ensure state-of-the-art techniques which is essential for a successful infection control intervention.

Comparison of hydroalcoholic rubbing and conventional chlorhexidine scrubbing for aseptic skin preparation in dogs

OBJECTIVE

To compare preparation time, ease of application, and elimination of skin contamination of 3 skin preparation methods for asepsis.

STUDY DESIGN

Experimental study.

ANIMALS

Healthy dogs (n = 6) with no clinical signs of skin disease.

METHODS

Three sites on each dog were randomly allocated to 1 of 3 preparation protocols for asepsis: (1) 5 scrubbings with chlorhexidine gluconate and rinsing (CHXG), (2) washing with mild soap prior to 3 rubbings with hydroalcoholic solution (soap-HAR), or (3) 3 rubbings with hydroalcoholic solution (HAR). The duration of each method of skin preparation was recorded. A Count-Tact agar plate was placed in the center of each site before, immediately after, 1 hour after, and 3 hours after antiseptic application. Plates were cultured, and colony forming units (CFU) were counted.

RESULTS

Skin preparation lasted an average of 375 seconds for CHXG, 240 seconds for soap-HAR, and 190 seconds for HAR (P = .00049). Nine CFU (median) were cultured from the skin prior to preparation, with no difference between sites on any animal or for any method. Colony forming units were not detected at any time on any site in any dog after antiseptic application.

CONCLUSION

Rubbing with hydroalcoholic (HA) solution was as effective as CHXG and prevented bacterial growth for at least 3 hours under these experimental conditions. Rubbing with hydroalcoholic solution was also faster and easier to perform.

CLINICAL SIGNIFICANCE

Because there is currently no known resistance to HA solution, preparation of the surgical site with HAR should be considered to prevent the emergence of bacterial resistance to chlorhexidine as well as potential cross-resistances to antibiotics. Transfer to clinical animals requires additional investigation.

Efficacy of application of an alcohol-based antiseptic hand rub or a 2% chlorhexidine gluconate scrub for immediate reduction of the bacterial population on the skin of dogs

OBJECTIVE To compare the efficacy of application of an alcohol-based antiseptic (80% ethyl alcohol) hand rub (ABAHR) with that of a 2% chlorhexidine gluconate scrub (CGS2) for immediate reduction of the bacterial population on the skin of dogs. ANIMALS 50 client-owned dogs with no evidence of skin disease. PROCEDURES On each dog, 2 areas of hair on the ventral aspect of the abdomen were clipped with a No. 40 blade and cleared of debris. A direct contact plate holding tryptic soy agar with polysorbate 80 and lecithin was gently pressed (for 2 seconds) on each skin site (preapplication sample). The CGS2 and ABAHR were each aseptically applied to 1 skin site on each dog. A direct contact plate was subsequently applied to each site in a similar manner (postapplication sample). All plates were cultured, and bacterial isolates were identified and quantified by the number of CFUs per plate. RESULTS Application of the CGS2 and ABAHR significantly decreased skin bacterial colony counts, compared with findings for preapplication samples. The number of CFUs per plate or postapplication percentage reduction in CFUs per plate did not differ between treatments. There were no adverse skin reactions associated with either application. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that applications of ABAHR and CGS2 were equally effective at immediately reducing the bacterial population on the skin of dogs, and there was no significant difference in percentage reduction in colony counts between the 2 applications.

Comparison of Aqueous and Alcohol-based Agents for Presurgical Skin Preparation Methods in Mice

Preparing the skin of rodents for surgery often involves multiple applications of antiseptic agents. However, fewer applications may achieve the same antiseptic outcome. We evaluated the antimicrobial efficacy and effects on intraoperative body temperature of various surgical scrub agents, including novel waterless alcohol-based (WAB) options. Prior to ventral laparotomy, female C57BL/6 mice were treated with 0.9% saline (control); 70% ethanol; 10% povidone-iodine alternated with saline or 70% ethanol; 2% chlorhexidine digluconate alternated with saline or 70% ethanol; or 1 of 3 WAB products-commercial surgical scrub A, commercial surgical scrub B, or a common commercial hand sanitizer. Core temperatures were recorded, and aerobic culture swabs were collected from the surgical site at multiple time points. Intraoperative temperature trajectories for animals treated with scrub B, 10% povidone-iodine with saline, or hand sanitizer did not differ from saline (control). Temperature trajectories of mice treated with other scrub agents did differ significantly from saline. Bacteria were not detected at the operative site after 3 scrubs of 70% ethanol or 10% povidone-iodine alternated with ethanol, 2 scrubs of scrub A or B, 1 scrub of hand sanitizer, and both 1 and 3 scrubs of 2% chlorhexidine alternated with ethanol. Scrub B and 2% chlorhexidine-ethanol demonstrated prolonged antibacterial efficacy. Histology of corresponding haired skin sections revealed no differences in postoperative healing between groups, and no postoperative infections occurred. These results indicate that various novel WAB disinfectants, particularly scrub B (61% ethanol and 1% chlorhexidine gluconate), mitigate intraoperative temperature effects associated with several traditional agents and combinations. Furthermore, reduction of skin bacterial load without adverse effects on healing was seen with fewer than triplicate applications of most tested agents. Ultimately effective skin preparation can be achieved by using only 1 or 2 applications of scrub, thus rendering the triplicate skin-prep method unnecessary in laboratory mice.

Comparison of an alcohol-based hand sanitation product with a traditional chlorhexidine hand scrub technique for hand hygiene preparation in an equine hospital

AIMS

To investigate the efficacy of an alcohol gel-based hand antisepsis protocol compared with a traditional chlorhexidine-based protocol under conditions of routine clinical contamination, and following heavy faecal contamination.

METHODS

Twelve adult participants were recruited and on four separate days completed a hand sanitation protocol using a chlorhexidine scrub or an alcohol-based gel, with hands that were grossly clean but contaminated or with faecal contamination. Bacterial samples were obtained from participants' hands before sanitation, immediately after and then 2 hours later. All samples were cultured on blood and MacConkey agar and bacterial colonies counted after 48 hours.

RESULTS

for clean contaminated hands, the percentage reduction in bacterial colonies on blood agar immediately after hand sanitation was similar for both protocols (p=0.3), but was greater for the alcohol gel than chlorhexidine after 2 hours (p=0.005). For hands with faecal contamination, the percentage reduction in bacterial colonies on blood agar was similar for both protocols immediately and 2 hours after sanitation (p>0.2), but positive cultures were obtained on blood agar from samples collected after both protocols, for almost all participants.

CONCLUSIONS

The results indicate equivalent efficacy of the alcohol-based gel and the pre-surgical chlorhexidine protocol.

CLINICAL RELEVANCE

The alcohol-based gel protocol is an effective hand asepsis technique for grossly clean contaminated hands and those following faecal contamination, with comparable efficacy to chlorhexidine based scrub.

Antibacterial Efficacy of Several Surgical Hand Preparation Products Used by Veterinary Students

OBJECTIVE

To compare the antibacterial efficacy of different surgical hand antisepsis protocols used by veterinary students.

STUDY DESIGN

Prospective, randomized, controlled study.

STUDY POPULATION

Third year veterinary students (n=45).

METHODS

The participants were randomly assigned to 4 of the following 12 hand preparation product/time combinations: nonabrasive hand scrub method with 4% chlorhexidine gluconate (CH); hand rub with a mixture of 30% 1-propanol and 45% 2-propanol solution (MPS), 70% 2-propanol solution (IPS), or 61% ethanol solution with 1% chlorhexidine gluconate (ES/CH), with a contact time of 1.5, 3, or 5 minutes. Antibacterial efficacy was assessed after surgical hand preparation and at the end of surgery. Log reductions of total bacterial colony forming unit (CFU)/mL and positive aerobic culture rates were compared using multivariable analysis of variance and multivariable logistic regression, respectively.

RESULTS

After surgical hand preparation, CH and ES/CH provided significantly higher log CFU reduction and lower positive culture rate for Gram-positive and spore-forming bacteria compared to MPS and IPS. Increase in contact time did not provide significant improvement in bacterial reduction. At the end of surgery, ES/CH provided significantly higher log CFU reduction compared to IPS and lower positive culture rate for Gram-positive bacteria compared to CH, MPS, and IPS. Increase in contact time significantly improved log CFU reduction in ES/CH and MPS groups.

CONCLUSION

In our population of veterinary students ES/CH hand rubs or CH scrubs were more effective in reducing bacterial CFU during surgical hand preparation than MPS or IPS.

Fighting surgical site infections in small animals: are we getting anywhere?

A diverse array of pathogen-related, patient-related, and caretaker-related issues influence risk and prevention of surgical site infections (SSIs). The entire surgical team involved in health care settings in which surgical procedures are performed play a pivotal role in the prevention of SSIs. In this article, current knowledge of SSI risk factors and prevention methods is reviewed. Although new avenues that can be explored in the prevention of SSIs in veterinary medicine are described, the main conclusion drawn is that the best method for prevention of SSI is to adhere to what we already know.

Observational study of patient and surgeon preoperative preparation in ten companion animal clinics in Ontario, Canada

Background

Surgical site infections (SSIs) are a recognized risk of any surgical procedure in veterinary medicine. One of the keys to prevention of SSIs is reducing exposure of the surgical site to endogenous and exogenous microbes, beginning in the preoperative period. While guidelines are available for preoperative preparation procedures, there has been no objective investigation of compliance with these recommendations in veterinary practices. The objectives of this pilot study were to describe preoperative patient and surgeon preparation practices in a sample of non-equine companion animal veterinary clinics, and to determine if there were any areas that consistently did not meet current guidelines.

Results

Observation of preparation practices was performed in 10 clinics over 9–14 days each using up to 3 small wireless surveillance cameras. Data were coded for 148 surgical patients, and 31 surgeons performing 190 preoperative preparations. When patient hair removal was observed, it was most commonly done using clippers (117/133, 88%), and in only one case was it performed prior to anesthetic induction. Patient contact time with soap ranged from 10-462 s (average of clinic means 75 s, average of clinic medians 67 s), and with alcohol from 3-220 s (average of clinic means 44 s, average of clinic medians 37 s). Alcohol-based hand rub (AHR) was used preoperatively in 2/10 facilities, but soap-and-water hand scrub was most commonly used at all clinics. Proximal-to-distal scrubbing was noted in 95/142 (67%) of soap-and-water scrubs. Contact time during surgeon hand preparation ranged from 7-529 s (average mean 121 s, average median 122 s) for soap-and-water and from 4-123 s (average mean 25 s, average median 19 s) for AHR. No significant changes in practices were identified over time during the observation period. Practices that did not conform to guidelines available in major companion animal surgical textbooks were commonly observed.

Conclusions

Some preoperative preparation practices were relatively consistent between clinics in this study, while others were quite variable. Contact times with preoperative preparatory solutions for both patients and surgeons were often shorter than recommended. Evidence-based guidelines for these procedures in veterinary medicine should be established and implemented in order to help reduce preventable SSIs, while maintaining efficiency and cost-effectiveness.