Wound Assessment, Aseptic Technique, and Basic Bandaging
Objective. Students will classify a wound by type and contamination level, irrigate and prepare it using aseptic technique, and apply a three-layer Robert Jones or modified bandage that maintains appropriate tension and is correctly documented.
This lesson, its worked examples and its practice questions has not yet been verified by a licensed clinician in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it to make decisions about any patient or medication. Always follow your instructor, your supervising professional, and current official references and regulations.
VoTechWorks program approval and accreditation are still in progress. Credentials are issued only by the certifying bodies named in each program, after their own exams.
Wound Classification
Before touching a wound, assess and classify it. The four standard categories guide every decision that follows.
Clean wounds result from sterile surgical incisions with no entry into the respiratory, gastrointestinal, or genitourinary tracts. Infection risk is low. Clean-contaminated wounds involve controlled entry into a body cavity under good technique, or minor breaks in sterile protocol. Contaminated wounds include traumatic wounds less than a few hours old, gross breaks in sterile technique, or accidental entry into an infected tract. Dirty or infected wounds are older traumatic wounds with devitalized tissue, foreign material, or frank infection already present.
Classification directly affects treatment: a clean surgical incision may be closed primarily, while a dirty wound often requires open management, lavage, and delayed closure.
Wound Healing Stages
All wounds heal through four overlapping phases.
1. Inflammatory phase (days 1–5): Vasodilation brings neutrophils and macrophages to clear bacteria and debris. The wound appears red, warm, and swollen — this is normal.
2. Debridement phase (overlaps inflammation): Macrophages and wound fluids remove dead tissue. Serosanguineous exudate is expected.
3. Proliferative (repair) phase (days 5 onward): Fibroblasts deposit collagen; granulation tissue forms a pink, granular bed. Contraction and epithelialization begin at wound edges.
4. Maturation (remodeling) phase (weeks to months): Collagen reorganizes and the scar gains tensile strength.
Recognizing which phase a wound is in helps the team choose the right contact layer and dressing change frequency.
Principles of Aseptic Technique
Aseptic technique means working in a way that keeps microorganisms away from a wound or sterile field. Key principles:
- Know your sterile field boundaries. The sterile field is the area covered by sterile drapes plus any sterile item opened onto it. Anything below table level or outside the drape edge is considered contaminated.
- Sterile items contact only sterile items. A sterile glove that touches an unsterile surface is contaminated and must be replaced.
- Face the sterile field. Never reach across a colleague or turn your back.
- Minimize air currents. Avoid reaching over an open sterile field; open supplies by peeling packaging away and dropping contents onto the field without touching the inner surface.
- If in doubt, throw it out. Any item whose sterility is uncertain is treated as contaminated.
Sterile Glove Donning
Open the outer wrapper, then the inner wrapper, exposing the gloves cuff-down. Pick up the first glove by the inner cuff only (skin touches the inside). Slide it on. With the gloved hand, slide fingers under the outer (sterile) cuff of the second glove to don it. Adjust fit without touching the outside of either glove with bare skin.
Wound Irrigation
Irrigation physically removes bacteria, debris, and devitalized tissue. The evidence-supported method for companion animal wounds uses a 35 mL syringe fitted with an 18-gauge needle or splash guard held approximately 2–3 cm from the wound surface. This setup generates approximately 8 psi of pressure — enough to dislodge bacteria without driving contaminants deeper. Use sterile isotonic saline. Irrigate until effluent runs clear. Avoid hydrogen peroxide or full-strength disinfectants directly in wounds; they damage healthy tissue and impair healing.
Safety point: wear personal protective equipment (gloves, eye protection, mask) during irrigation — splash-back is common.
Three-Layer Bandage: Modified Robert Jones
A Robert Jones bandage is a heavily padded compressive limb bandage. The modified Robert Jones uses less padding than the classic version, making it practical for routine wound protection. It has three layers:
Layer 1 — Contact (Primary) Layer
Placed directly on the wound. Choose based on wound type:
- Non-adherent pads (e.g., Telfa) for granulating wounds — removes easily without disturbing new tissue.
- Wet-to-dry gauze for wounds needing mechanical debridement (faculty will direct when this is appropriate).
Layer 2 — Padding (Secondary) Layer
Cast padding or roll cotton applied in overlapping spiral turns (50% overlap each pass) from distal to proximal. This layer absorbs exudate, protects bony prominences, and provides even compression. Apply smoothly — wrinkles concentrate pressure and can cause pressure necrosis.
Layer 3 — Outer (Tertiary) Layer
Conforming gauze is applied first to hold the padding, followed by cohesive bandage material (such as Vetrap). Apply with gentle, even tension from distal to proximal. Too tight restricts circulation; too loose allows the bandage to slip and lose its protective function.
The Two-Finger Rule
After the bandage is complete, you should be able to slide two fingers under the proximal edge without forcing them. If you cannot, the bandage is too tight and must be replaced immediately. If the bandage slides or the fingers go in easily past the knuckles, it is too loose.
Safety point: check the toes (if exposed) for swelling, coldness, or pain, which indicate compromised circulation. Document and report any abnormal findings to the supervising veterinarian.
Documentation
Every bandage placed is a medical event. In the patient record note:
- Date and time
- Wound classification and description
- Bandage type and layers used
- Condition of wound at time of bandage change
- Initials of person who applied it
- Next scheduled change or recheck
Accurate records protect the patient, support continuity of care, and are required for NAVTA-approved programs and VTNE competency domains.
Key terms8
Materials: Saline irrigation solution, 35 mL syringes, 18-gauge needles, sterile gloves (multiple sizes), sterile drapes, non-adherent wound pads, cast padding/roll cotton, conforming gauze, cohesive bandage material (Vetrap or equivalent), bandage scissors, wound mannequin limbs, bandage documentation forms
Check: Faculty-scored bandage checklist: correct layering sequence, appropriate tension (two-finger rule met), no wrinkles causing pressure points, and completed documentation; pass mark is all critical items met and 80% of minor items met.
Practice check8
Answer each question, then check it. Nothing is recorded; this is your own practice.
