Surgical Scrub Techniques and Sterile Gowning Protocols

By Dr. Zubair Khalid, DVM, MS, PhD · 2026-08-11

Key Takeaways

• Surgical hand antisepsis aims for rapid, sustained reduction of bacterial flora, not sterilization, with hands being a primary vector for surgical site contamination. Resident flora, residing in deeper skin layers and follicles, require chemical antisepsis for suppression.
• Chlorhexidine gluconate (CHx) offers sustained residual activity due to binding to the stratum corneum, while alcohol-based rubs (ABR) provide rapid kill but minimal persistence. CHx/alcohol combinations offer both immediate efficacy and residual activity, demonstrating superior bacterial reduction compared to CHx alone in some equine studies.
• Water-based scrubs (5 minutes standard) and ABRs (follow manufacturer instructions) are both effective, with ABRs offering faster preparation and reduced skin irritation, particularly useful in field settings. However, ABRs are ineffective on grossly contaminated hands, necessitating prior washing with soap and water.
• Common aseptic breaches include contact of sterile towels or gowns with nonsterile surfaces, and improper scrubbing technique, occurring in nearly half of student procedures and indicating persistent skill deficits. These errors can increase the time required for gowning and gloving.
• Closed gloving technique is preferred for initial gowning to prevent bare-hand contact with the gown exterior, while open gloving is reserved for glove changes. Double gloving is recommended for procedures exceeding 90 minutes to mitigate increased glove perforation rates.
• Species and setting modifications are crucial; large animal surgery may require waterproof overlays, while production animal practice often necessitates adaptation to limited facilities with ABRs as a practical default for non-visibly soiled hands.

This article provides a procedural reference for veterinary surgeons, residents, and senior students performing surgical hand antisepsis and sterile gowning. It addresses the scientific basis for preoperative hand preparation, compares water-based and alcohol-based techniques across species, and details the stepwise execution of scrub, rub, gown, and glove protocols with attention to common errors. The content is written for practitioners who already understand aseptic principles and require a precise, current reference for technique selection and quality assurance.

Surgical site contamination originates from multiple sources, but the surgical team's hands remain a primary vector. The hands harbour transient bacteria acquired from patient contact and resident flora residing in deeper skin layers, hair follicles, and sebaceous glands. Resident flora resist mechanical removal and require chemical antisepsis for suppression. The goal of preoperative hand preparation is not sterilization but rapid, sustained reduction of both bacterial populations to the lowest achievable level for the duration of the procedure.

At a Glance

Pharmacology of Antiseptic Agents

Chlorhexidine gluconate disrupts bacterial cell membranes and binds to the stratum corneum, providing substantive residual activity that persists for hours. Its activity is minimally affected by organic material and it retains efficacy in the presence of residual soap. Povidone-iodine releases free iodine that oxidises microbial proteins and nucleic acids. Its action is rapid but lacks persistence because the iodine is neutralised by skin proteins, requiring repeated application for sustained effect. Alcohol denatures proteins and provides the fastest kill of all agents but evaporates quickly, leaving no residual protection.

The comparative efficacy of these agents in veterinary surgery has been examined in equine settings. A prospective randomised trial comparing four techniques found that a CHx/alcohol combination product applied by rubbing produced significantly lower bacterial counts than CHx scrub alone, with immediate log reductions of 3.1 versus 2.4 colony forming units respectively. The sole alcohol rub achieved a 2.1 log reduction, indicating that combining CHx with alcohol captures both rapid kill and residual activity. A separate equine study comparing an alcohol-based hand rub with traditional 4% CHx sponges found no significant difference in mean bacterial counts between techniques across all sampling periods, supporting ABR as an equivalent alternative in clinical practice.

Water-Based Scrub Technique

The traditional water-based scrub uses either CHx 4% or PVP-I 7.5% with a sponge or brush. A 5-minute scrub provides adequate bacterial reduction for both clean and dirty procedures, and no significant difference exists between one-brush and two-brush techniques. Brushes are unnecessary for efficacy and increase the risk of skin damage, which paradoxically raises bacterial shedding from disrupted epithelium.

Perform the scrub in the following sequence. Remove jewellery and watches. Use a neutral soap and water to remove gross contamination from hands and forearms, then rinse thoroughly. Open the sterile scrub brush or sponge and wet it. Starting at the fingertips, work the agent between all fingers, over the dorsal and palmar surfaces of each hand, and progress proximally to the elbows. Keep the hands elevated above the elbows throughout so that water and suds run from the cleanest area toward the dirtiest. Spend the majority of the 5 minutes on the hands and fingers, with less time on the forearms. Rinse in one direction only, from fingertips to elbows, and do not shake excess water from the hands. Dry with a sterile towel, using one side for each hand and progressing from fingers to elbows without returning to previously dried areas.

Alcohol-Based Hand Rub Technique

Alcohol-based hand rubs are applied to dry, grossly clean hands without water. The World Health Organization recommends ABR for surgical hand preparation in human surgery, and equine studies demonstrate equivalent efficacy to water-based CHx scrubbing. The technique requires a sufficient volume of product, typically 6 to 10 mL depending on formulation, applied to the hands and forearms and rubbed until dry. The manufacturer's stated application time must be followed, usually 90 seconds to 3 minutes.

Alcohol rubs are particularly useful in field settings or when running water is unavailable. However, they are ineffective in the presence of organic material. A study of hand hygiene in an equine hospital found that after heavy fecal contamination, positive cultures were obtained from almost all participants following both alcohol gel and CHx protocols, confirming that gross contamination must be removed with soap and water before any antiseptic technique. The same study found that alcohol gel provided greater bacterial reduction than CHx at 2 hours after application on clean contaminated hands, supporting its use when sustained efficacy is required.

Common Errors in Scrub and Gowning

Observational data from veterinary teaching hospitals reveal that aseptic protocol breaches occur in nearly half of student procedures. The most frequent errors are contact of the sterile towel with nonsterile surfaces, contact of the gown with nonsterile surfaces, touching sterile objects with bare hands, and improper scrubbing technique. These breaches occur regardless of the student's stage of rotation or previous surgical experience, indicating that they reflect persistent skill deficits instead of inexperience alone. Students who committed breaches took longer to gown and glove, averaging 4.6 minutes versus 3.7 minutes for those without breaches, suggesting that rushed or inefficient technique increases error risk.

Specific technical points reduce breach frequency. When drying hands, the sterile towel must be unfolded without allowing it to drop below waist level or contact the scrub sink. The gown is picked up by the inner surface only, and the hands are advanced into the sleeves without touching the exterior. The closed gloving method keeps the hands inside the gown cuffs while grasping the glove, eliminating bare-hand contact with the glove exterior.

Technique Selection and Clinical Decision Making

The choice between water-based scrub and alcohol-based hand rub depends on clinical context, available facilities, and patient status. Comparative trials in equine surgery have found no significant difference in bacterial reduction between chlorhexidine scrub and alcohol-based rub techniques, with one prospective study reporting equivalent efficacy for an alcohol-based hand rub (Avagard) and traditional 4% chlorhexidine gluconate sponges prior to elective surgery in horses da Silveira et al., 2016. A separate randomised trial comparing four techniques found that a chlorhexidine-alcohol combination product applied by rub achieved significantly lower bacterial counts than chlorhexidine scrub, while 80% ethanol alone produced the smallest immediate reduction Biermann et al., 2019.

For routine clean procedures in a hospital setting with intact skin, alcohol-based rubs offer comparable efficacy with shorter preparation time and reduced skin irritation. Water-based scrubs remain appropriate when hands are visibly soiled, when repeated procedures require multiple preparations in a single session, or when the surgical team prefers the tactile feedback of a timed scrub. In field settings or ambulatory practice where running water may be limited, alcohol-based rubs are the practical default, provided hands are grossly clean before application.

Patient status changes the decision in specific ways. For immunocompromised patients, oncology patients receiving chemotherapy, or patients undergoing implant placement, the sustained antimicrobial activity of chlorhexidine may justify a water-based scrub despite the longer preparation time. For emergency procedures where every minute counts, an alcohol-based rub with a chlorhexidine-alcohol combination product provides rapid, broad-spectrum reduction without the need for drying towels or running water.

Comparative Table of Scrub Agents

Contact times assume manufacturer instructions are followed. Current formulary and label references must be consulted for specific product concentrations and application protocols, as formulations vary between manufacturers and jurisdictions.

Gowning and Gloving Sequence

Closed gloving technique is the standard for initial gowning because it prevents bare-hand contact with the gown exterior. The sequence proceeds as follows: after the surgical scrub and hand drying, the gown is lifted by the inner surface at the neckline, held away from the body, and allowed to unfold without touching the floor or surrounding surfaces. The hands are inserted into the sleeves only to the level of the cuff, not through the cuff. The circulator pulls the gown over the shoulders and secures the neck and back closures. With hands still inside the sleeves, the surgeon grasps the glove through the sleeve fabric, positions the glove over the opposite hand, and pulls the glove cuff over the sleeve cuff. The process is repeated for the second hand.

Open gloving is reserved for situations where the gown has been donned but gloves must be replaced, or when a second pair of gloves is added over the first. The bare hand touches only the inner surface of the glove cuff, while the gloved hand touches only the outer surface. This distinction is the most common source of contamination during regloving.

For double gloving, the outer glove is applied over the inner glove using the closed technique if the inner glove is already in place. The outer glove should be one half size larger to prevent compression of the fingers and loss of tactile sensitivity. Some surgeons prefer to apply the inner pair, then the gown, then the outer pair, which allows both pairs to be applied with the closed technique.

Troubleshooting Gowning Breaches

Observational data from veterinary teaching hospitals show that aseptic protocol breaches occur in nearly half of student procedures, with the most frequent errors being contact of the sterile towel with nonsterile surfaces, contact of the gown with nonsterile surfaces, touching sterile objects with bare hands, and improper scrubbing technique Souders and Kim, 2025. The same study found that students who committed a breach took longer to gown and glove, suggesting that rushed or uncertain technique increases contamination risk instead of reducing it.

When a breach occurs, the contaminated item is discarded and the surgeon rescrubs or reapplies antiseptic before redonning. The threshold for rescrubbing versus regloving depends on the nature of the contact. Contact of a gloved hand with a nonsterile surface requires glove change only, provided the gown sleeve cuffs remain intact. Contact of bare skin with any nonsterile surface requires a full rescrub. Contact of the gown with a nonsterile surface requires gown change and rescrub of the hands, because the hands pass through the contaminated gown during removal.

Species and Setting Modifications

Large animal surgery presents specific challenges. The height of the surgical table, the size of the patient, and the need for additional personnel to position the patient all increase the risk of gown contamination. In equine surgery, the surgeon should gown and glove in a designated preparation area away from the patient, then approach the surgical site with hands clasped at chest level. For standing procedures, a waterproof gown overlay or impervious sleeve covers may be necessary to prevent strike-through from blood or lavage fluid.

In small animal practice, the primary modification is the use of smaller glove sizes and the need for greater manual dexterity during microsurgical procedures. Some surgeons prefer thinner gloves for delicate work, accepting a higher perforation rate in exchange for improved tactile feedback. For procedures longer than 90 minutes, double gloving is recommended because glove perforation rates increase with duration, and the inner glove provides a barrier if the outer glove fails.

Production animal practice often requires adaptation to limited facilities. When running water is unavailable, alcohol-based rubs are the only practical option, but hands must be visibly clean before application. When water is available but the setting is nonsterile, a water-based scrub followed by an alcohol-based rub provides additional reduction. The surgeon should carry personal antiseptic supplies, as farm-provided products may be expired, diluted, or contaminated.

Regional differences in product availability and regulatory status affect agent selection. Chlorhexidine is widely available globally, but povidone-iodine may be more accessible in some regions. Alcohol-based rubs formulated for surgical use are increasingly standard in Europe and North America but may be less available in other regions. The surgeon should select from what is available and verify the concentration and expiration date of each product before use.

Complications and Failure Modes

Surgical site infection remains the sentinel outcome measure for aseptic technique failure, but more immediate complications arise during the scrub and gowning process itself. Contact dermatitis from repeated chlorhexidine or povidone-iodine exposure presents as erythema, pruritus, and scaling of the hands and forearms. Detection is early and visual: inspect the skin before each scrub, because compromised integument harbours higher bacterial densities and increases the risk of contaminating the sterile field. Alcohol-based rubs cause less skin irritation than brush scrubbing, which supports their use in personnel with sensitive skin Biermann et al., equine surgical hand antisepsis trial.

Chemical conjunctivitis or corneal injury can occur when antiseptic splashes the surgeon's face during the scrub. Prevention relies on positioning the elbows higher than the hands during the water-based scrub and keeping the face turned away from the splash zone. Detection is immediate: burning, tearing, and blepharospasm. The affected eye should be irrigated with sterile saline or lactated Ringer's solution for at least 15 minutes, and the surgeon must not proceed to gown until the episode is resolved and the hands have been re-scrubbed if contamination occurred.

Failure of the gown or gloves to maintain integrity is a distinct failure mode. Gown perforation at the elbows or chest occurs most often during draping or when leaning over the patient. Glove perforation is reported in a substantial proportion of procedures and is frequently unnoticed by the surgeon. Detection requires vigilance: visible blood or fluid tracking onto the glove surface, a sudden change in tactile sensation, or the appearance of moisture inside the glove. Double gloving provides an indicator system when the inner glove is a contrasting color, and it reduces the risk of skin contact with patient fluids. When a breach is detected, the glove must be changed immediately using the closed technique, and the gown should be replaced if the forearm or sleeve is contaminated.

Common Errors and Corrective Actions

Observational data from veterinary teaching hospitals show that at least one aseptic protocol breach occurs in nearly half of student scrubbing, gowning, and gloving procedures Souders and Kim, aseptic protocol breaches in veterinary students. The most frequent errors are contact of the sterile towel with nonsterile surfaces, contact of the gown with nonsterile surfaces, touching sterile objects with bare hands, and improper scrubbing technique. Notably, breaches were not associated with stage of rotation or previous surgical experience, which indicates that repetition alone does not correct faulty technique. Structured feedback and direct observation are required.

The towel-drying step is a common source of contamination. The towel is held at one end and the opposite end is used to dry each hand and forearm with a separate pass. A frequent error is allowing the towel to drape over the scrub sink or the surgeon's gown. The corrective action is to hold the towel well away from the body and to discard it after both hands are dried, before gowning begins.

Gowning errors typically involve touching the exterior of the gown with bare hands or allowing the gown to contact the floor or a table edge. The closed gloving technique, in which the hands remain inside the gown cuffs until the gloves are pulled over them, reduces the risk of bare-hand contact with the glove exterior. When a breach occurs, the contaminated item must be discarded and replaced. The time cost of correcting a breach is measurable: students who made an error took nearly one minute longer to complete gowning and gloving than those who did not Souders and Kim, aseptic protocol breaches in veterinary students. This delay is acceptable when it prevents a contaminated field.

Improper scrub technique includes incomplete coverage of the nail beds, inadequate contact time with the antiseptic, and rinsing from the fingers toward the elbows in a manner that allows contaminated water to flow back over clean skin. The corrective action is to follow a fixed sequence: nail cleaning, timed application of antiseptic to each hand and forearm, and one-way rinsing with the hands held higher than the elbows.

Evidence Limitations and Divergent Expert Opinion

The comparative efficacy of water-based scrubs and alcohol-based rubs is supported by several equine studies, but the evidence base has important limits. A randomised trial in equine surgery found that a chlorhexidine-alcohol combination product produced significantly lower bacterial counts than chlorhexidine scrub alone, while a sole alcohol rub had the lowest immediate reduction Biermann et al., equine surgical hand antisepsis trial. Other equine studies report equivalent efficacy between alcohol-based rubs and chlorhexidine scrubs da Silveira et al., alcohol-based hand rub versus chlorhexidine scrub in horses and Edwards et al., alcohol-based hand sanitation in an equine hospital. These findings are not contradictory so much as context-dependent: the products, contact times, and outcome measures differ across studies.

The evidence base is drawn almost entirely from equine and human surgery. Data from small animal, ruminant, and porcine practice are sparse. Whether the equivalence of alcohol-based rubs holds in high-contamination settings, such as emergency laparotomy in a ruminant with a ruptured viscus, is not established. Expert opinion still differs on whether a water-based scrub should precede the first alcohol-based rub of the day, and on the required duration of the water-based scrub when it is used. Some authorities advocate a full five-minute scrub, while others accept three minutes for chlorhexidine. The available comparative data do not resolve this question Wan et al., surgical scrub methods for large animal surgeons.

Referral, Consultation, and Reporting

Most breaches of aseptic technique are managed locally by discarding the contaminated item and repeating the affected step. Referral to a specialist is warranted when a surgeon develops recurrent contact dermatitis that does not respond to a change in antiseptic agent, because this may indicate an allergy requiring patch testing and occupational health input. A veterinary dermatologist or a human occupational medicine service can provide this evaluation.

Laboratory involvement is indicated when a surgical site infection occurs despite apparently correct aseptic technique. Aerobic and anaerobic culture with susceptibility testing of the infected site guides antimicrobial selection. When multiple infections cluster in a single surgeon, a single theatre, or a single time period, the laboratory should be asked to type the isolates to determine whether a common source exists.

Regulatory reporting obligations vary by jurisdiction. In many regions, a cluster of surgical site infections in a veterinary teaching hospital or referral practice is reportable to the relevant veterinary licensing body or to a hospital infection control committee. Practitioners should consult their local regulatory authority for the applicable requirements AVMA professional practice resources. International movement of animals with postoperative complications is governed by separate trade and health standards WOAH terrestrial animal health standards, which are relevant when a surgical infection affects an animal intended for export.

Troubleshooting Table

Frequently Asked Questions

What is the minimum acceptable hand antisepsis protocol when running water is unavailable?

When running water and sinks are unavailable, an alcohol-based hand rub is the practical alternative, provided the hands are visibly clean. The sequence is to remove gross debris with wipes or a dry paper towel, apply 3 to 5 mL of alcohol rub to dry hands, and rub until completely dry, covering all surfaces including nails and interdigital spaces. Do not use water after the rub. Evidence from equine hospital settings shows alcohol-based products achieve bacterial reduction equivalent to traditional chlorhexidine scrubs for clean-contaminated hands, though heavy fecal contamination reduces efficacy for both methods (alcohol gel versus chlorhexidine scrub comparison). For grossly contaminated hands, a water source remains necessary before relying on alcohol rub alone.

How should I manage a detected gowning breach when no replacement gown is available?

If a sterile gown touches a nonsterile surface and no replacement exists, the safest option is to remove the gown and regown if any sterile gown remains. When none is available, you must decide between aborting the procedure or continuing with documented increased risk. If the breach is minor, such as the gown cuff touching the drape edge, and the surgical field is already established, some surgeons continue while covering the contact point with a sterile towel or drape. Breaches involving the front chest or sleeves over the sterile field are more serious. Observational data from veterinary teaching hospitals show gown contact with nonsterile surfaces is among the most common student errors, and longer donning times correlate with more breaches. Document the breach in the surgical record and discuss it with the team before proceeding.

Does the choice of antiseptic differ for equine versus small animal surgery?

The evidence base for hand antisepsis is strongest in equine surgery, where multiple trials compare chlorhexidine scrubs, alcohol rubs, and combination products. A randomised equine trial found a chlorhexidine-alcohol combination rub achieved significantly lower bacterial counts than chlorhexidine scrub alone, while a sole alcohol rub had the lowest immediate reduction. Another equine study found no significant difference between alcohol rub and chlorhexidine scrub across the perioperative period. For small animal practice, the same principles apply, but the evidence base is extrapolated instead of directly tested. Consider case duration: for prolonged procedures, chlorhexidine-based products provide sustained activity, whereas alcohol rubs offer rapid immediate kill with less residual effect. Product availability and surgeon familiarity often determine the practical choice.

What is the correct response when a sterile glove tears during surgery?

A torn glove must be replaced immediately. Remove the glove using the closed technique if possible, or have a circulating assistant grasp the glove cuff and peel it off without touching your skin. Perform a rapid hand rub with alcohol-based solution on the exposed hand, then don a new sterile glove. If the tear is on the dominant hand and the procedure is at a critical stage, ask an assistant to hold tension or pack the site while you reglove. Do not continue with a torn glove, as bacterial counts under gloves rise progressively during surgery. Studies of scrub efficacy show bacterial regrowth occurs within 120 minutes of scrubbing, so a torn glove late in a long procedure carries meaningful contamination risk. Record the glove change in the operative notes.

How should I document hand antisepsis and gowning in the medical record?

The surgical record should include the antiseptic product and technique used, the surgeon and assistant names, the time of hand preparation, and any breaches or glove changes. This documentation supports infection control review if a surgical site infection develops postoperatively. Professional practice resources from the AVMA emphasize that accurate surgical records are part of standard of care and support outcome tracking. If a breach occurred, note it factually without assigning blame, for example "gown cuff contacted drape, replaced before incision." For research or quality improvement, record the specific product lot number and scrub duration. This level of detail allows retrospective analysis of infection clusters and supports compliance audits within teaching hospitals or multi-surgeon practices.

How do I explain a surgical site infection to an owner when aseptic technique was followed correctly?

Explain that surgical site infections occur despite correct aseptic technique in a small percentage of cases, because no preparation method eliminates all bacteria. The MSD Veterinary Manual describes surgical site infection as a recognized complication influenced by patient factors, procedure duration, and tissue handling, not solely by skin preparation. Describe the specific steps taken, including hand antisepsis, sterile gowning, and draping, to reassure the owner that protocols were followed. Avoid defensiveness. Acknowledge the infection, outline the treatment plan, and state that the case will be reviewed. If a breach occurred, be transparent about it and explain the corrective measures. This approach maintains trust while accurately representing the limitations of aseptic technique.

Related Clinical & Scientific Guides

• Perioperative Antibiotic Prophylaxis: Timing and Selection
• Surgical Approaches to the Femur and Stifle
• Fracture Healing Assessment: Radiographic and Clinical Evaluation

References and Further Reading

• Prospective, randomised clinical trial of four different presurgical hand antiseptic techniques in equine surgery.. 2019.
• Foaming Betadine Spray as a potential agent for non-labor-intensive preoperative surgical site preparation.. 2015.
• Aseptic protocol breaches are common among veterinary students scrubbing, gowning, and gloving into surgery.. 2025.
• Comparison of an alcohol-based hand sanitation product with a traditional chlorhexidine hand scrub technique for hand hygiene preparation in an equine hospital.. 2017.
• Comparison of an alcohol-based hand rub and water-based chlorhexidine gluconate scrub technique for hand antisepsis prior to elective surgery in horses.. 2016.
• Evaluation of surgical scrub methods for large animal surgeons.. 1997.
• American College of Veterinary Surgeons Animal Health Resources. American College of Veterinary Surgeons.
• MSD Veterinary Manual, Professional Edition. MSD Veterinary Manual.
• American Veterinary Medical Association Practice Resources. American Veterinary Medical Association.

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• Surgical Biopsy Techniques: Incisional vs Excisional
• Surgical Draping Materials and Techniques for Contamination Control
• Surgical Instrumentation: Essential Set and Handling Techniques

This article is educational professional reference material for veterinary audiences. It is not a substitute for veterinary diagnosis, individual clinical judgment, current product labeling, or applicable regulatory requirements.