6.2 Aseptic Non-Touch Technique (ANTT) & Wound Dressing Selection
Key Takeaways
- The primary objective of ANTT in Irish nursing practice is the continuous identification and rigorous protection of Key-Parts and Key-Sites to eliminate cross-contamination.
- Standard ANTT is used for simple, short procedures with few Key-Parts using clean non-sterile gloves, whereas Surgical ANTT mandates sterile gloves and a full sterile drape field.
- Aseptic dressing changes require strict adherence to surface decontamination contact times (30–60 s), single-stroke cleansing from cleanest to dirtiest, and appropriate clinical waste segregation.
- Moist wound healing accelerates re-epithelialisation up to threefold compared to dry air exposure by promoting autolysis, cellular migration, and growth factor preservation.
- Dressing selection is matched to tissue type and exudate: hydrogels rehydrate dry necrosis, alginates absorb heavy exudate, and hydrocolloids promote autolysis but are strictly contraindicated in infected wounds.
Last updated: September 2026
5.2 Aseptic Non-Touch Technique (ANTT) & Wound Dressing Selection
In Irish healthcare facilities, healthcare-associated infections (HCAIs) and surgical site infections (SSIs) represent significant clinical and economic burdens. The Health Service Executive (HSE) and the Nursing and Midwifery Board of Ireland (NMBI) mandate the universal application of Aseptic Non-Touch Technique (ANTT) for all invasive clinical procedures and wound care. In the RCSI Faculty of Nursing and Midwifery Practical Examination (OSCE), the aseptic dressing change station is a high-stakes, core assessment where examiners rigorously evaluate whether the candidate maintains sterility, manages critical fields, and correctly selects dressings based on the biological requirements of the wound bed.
[!IMPORTANT] The Core Philosophy of ANTT: ANTT is defined by one primary clinical imperative: Protect Key-Parts and Key-Sites at all times. Asepsis is not achieved by wearing sterile gloves alone; it is achieved by systematically identifying Key-Parts and ensuring they never contact non-sterile surfaces, contaminated gloves, or unsterilized environments.
1. The ANTT Clinical Framework: Key-Parts and Key-Sites
The ANTT framework, developed by The Association for Safe Aseptic Practice (ASAP) and embedded in Irish National Clinical Guidelines, categorizes clinical procedures into two distinct operational methodologies based on procedure duration, technical complexity, and the number and size of Key-Parts.
Definitions of Core Components
- Key-Parts: The sterile components of medical equipment that will come into direct or indirect contact with liquid infusions, sterile fields, or the patient's breached body tissues. Examples: the wound-contact surface of a primary dressing, the tips of sterile forceps, the nozzle of a sterile saline ampoule, syringe tips, and catheter lumens.
- Key-Sites: The patient's open body areas where natural skin or mucosal barriers are breached, creating a portal of entry for pathogens. Examples: open surgical wounds, pressure injuries, chronic ulcers, vascular access puncture sites, and the urinary meatus.
- Aseptic Fields:
- General Aseptic Field: A promoting field (e.g., a decontaminated clinical dressing tray or trolley) used when Key-Parts are individually protected by caps or micro-critical fields.
- Critical Aseptic Field: A fully sterile field (e.g., a sterile paper drape) where all working surfaces are sterile and Key-Parts may be laid directly onto the field.
- Micro-Critical Aseptic Field: The inside of sterile packaging or device caps that protect an individual Key-Part until the exact moment of clinical application.
Standard ANTT versus Surgical ANTT
| Assessment Parameter | Standard ANTT | Surgical ANTT |
|---|---|---|
| Clinical Complexity | Simple, short duration (<20 minutes), technically straightforward procedures. | Complex, prolonged duration (>20 minutes), technically challenging procedures. |
| Key-Parts & Key-Sites | Few in number, small in surface area, easily protected. | Numerous, large surface areas, open cavities, or deep invasive sites. |
| Aseptic Working Field | General Aseptic Field (decontaminated clinical tray/trolley) with Key-Parts protected in micro-critical fields. | Critical Aseptic Field (sterile paper drapes covering the entire procedural surface). |
| Glove Requirement | Clean, non-sterile examination gloves are acceptable, provided a strict non-touch technique is maintained (Key-Parts are never touched with bare or gloved hands; forceps or packaging handles are used). | Sterile gloves are mandatory because direct manual contact with Key-Parts and Key-Sites cannot be avoided during manipulation. |
| Clinical Examples | Simple surgical wound dressing changes, peripheral intravenous cannulation, subcutaneous injections, accessing an established peripheral line. | Complex cavity wound dressings, central venous catheter (CVC) insertion and dressing changes, surgical operations, urinary catheterisation, large burn dressings. |
2. Step-by-Step Procedure: Sterile Dressing Change in the RCSI OSCE
In the 10-minute RCSI OSCE station, candidates must execute a standard or surgical dressing change smoothly within the 8-minute active performance period. Every phase contains critical checkpoints assessed by the examiner.
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| 8-STAGE OSCE CLINICAL DRESSING CHANGE SEQUENCE |
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| 1. Patient Verification & Pain Assessment (Check 3 IDs, assess NRS 0-10) |
| v |
| 2. Trolley Decontamination (Clean top to bottom, wait 30-60s dry time) |
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| 3. Hand Hygiene & Equipment Assembly (Sterile pack, dressings, 0.9% NaCl) |
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| 4. Establishing Sterile Field (Open pack corners only, pour saline safely) |
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| 5. Removal of Old Dressing (Clean gloves/apron, assess exudate, discard) |
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| 6. Hand Hygiene & Regloving (6-step technique, don clean or sterile gloves) |
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| 7. Wound Cleansing & Dressing Application (Single stroke, clean to dirty) |
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| 8. Waste Segregation, Trolley Wipe & Documentation (TIME, pain, sign/PIN) |
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Step-by-Step OSCE Dressing Procedure & Critical Evaluator Checkpoints
| Procedural Phase | Clinical Execution Actions | Critical Safety & ANTT Evaluator Checkpoints |
|---|---|---|
| Phase 1: Patient Verification & Preparation | - Introduce self, state designation (Candidate / Registered General Nurse).<br/>- Verify patient identity using three identifiers: full name, date of birth, and Medical Record Number (MRN) against the wristband and chart.<br/>- Assess procedural pain using a 0–10 Numerical Rating Scale (NRS); verify if prescribed analgesia was given 20–30 minutes prior.<br/>- Explain procedure, confirm understanding, obtain verbal consent.<br/>- Ensure patient privacy (close curtains); position comfortably, exposing only the wound site. | Critical Failure Checkpoint: Performing a procedure on an unverified patient or exposing the wound without assessing procedural pain. Exposing excessive body surface violates patient dignity and promotes hypothermia. |
| Phase 2: Trolley Decontamination | - Perform hand hygiene (alcohol rub or soap/water for 20–30 seconds).<br/>- Don clean disposable apron.<br/>- Inspect two-tier clinical dressing trolley.<br/>- Decontaminate trolley using hospital-approved disinfectant wipes (e.g., Clinell detergent/disinfectant wipe). Wipe top shelf first, then legs, then bottom shelf using a continuous S-shaped motion from clean to dirty.<br/>- Allow surface to air-dry completely for 30–60 seconds to achieve full microbial kill and prevent disinfectant strike-through. | Critical Failure Checkpoint: Placing sterile equipment on a wet trolley or failing to wait for the disinfectant to air-dry. Touching uncleaned trolley legs and then touching the top shelf without re-cleaning. |
| Phase 3: Equipment Assembly | - Perform hand hygiene.<br/>- Gather all required equipment: sterile dressing pack (containing gallipot, sterile field, gauze swabs, disposable forceps), sterile 0.9% sodium chloride ampoules, selected primary and secondary dressings, sterile/clean gloves, yellow healthcare risk waste bag, and hypoallergenic retention tape.<br/>- Check all packaging for integrity, dry seals, and expiry dates. | Critical Failure Checkpoint: Using expired equipment or items with compromised packaging integrity (e.g., water stains, tears). |
| Phase 4: Establishing the Sterile Field | - Perform hand hygiene.<br/>- Affix the yellow clinical waste bag to the side of the trolley without contaminating the top surface.<br/>- Carefully peel open the outer plastic wrapper of the sterile dressing pack; discard wrapper into general waste.<br/>- Grasping only the outermost 1–2 cm border/corners of the sterile paper drape, open the four folds outward, creating a pristine sterile field on the top shelf.<br/>- Open sterile 0.9% saline ampoule; pour into the gallipot from a height of ~10–15 cm without touching the nozzle to the sterile field or splashing.<br/>- Peel open additional sterile dressing packages using a non-touch peel-back method, dropping them gently onto the sterile field without hovering arms over the field. | Critical Failure Checkpoint: Reaching directly over an open sterile field with non-sterile arms. Splashing saline onto paper drapes (moisture penetration causes capillary action strike-through, pulling microbes through the paper). Touching the inner sterile field with bare hands. |
| Phase 5: Removing Existing Dressing | - Don clean non-sterile examination gloves.<br/>- Gently loosen adhesive tape by peeling parallel to the skin toward the wound, supporting adjacent tissue to prevent epidermal stripping.<br/>- Lift old dressing away from the wound bed.<br/>- Closely inspect the inner surface of the removed dressing for exudate volume, colour, consistency, and odour (TIME evaluation).<br/>- Invert the dressing into the glove or discard directly into the yellow clinical waste bag.<br/>- Remove gloves and apron; discard into clinical waste.<br/>- Perform 6-step hand hygiene immediately. | Critical Failure Checkpoint: Failing to perform hand hygiene immediately after removing soiled gloves. Touching clean trolley equipment or sterile fields while wearing gloves contaminated by the old dressing. |
| Phase 6: Wound Cleansing | - Don clean gloves (for Standard ANTT with forceps) or sterile gloves (for Surgical ANTT).<br/>- Saturate sterile gauze swabs in 0.9% sodium chloride; squeeze excess fluid using forceps over the gallipot.<br/>- Clean the wound from cleanest area to dirtiest area:<br/> * Surgical incision: Single downward stroke along the suture line; discard swab. Clean parallel lateral aspects with fresh swabs; discard each immediately.<br/> * Open ulcer / cavity: Clean from the centre outwards, or from cleanest margins to dirtiest base depending on exudate.<br/>- Rule: Exactly one swab per single stroke; never re-dip a used swab into the saline gallipot.<br/>- Dry the peri-wound skin gently with dry sterile gauze using light patting (do not rub). | Critical Failure Checkpoint: Re-dipping a used, contaminated swab into the sterile saline. Wiping back and forth in a sawing motion across a surgical incision. Allowing wet saline to run down into surrounding bedding. |
| Phase 7: Dressing Application | - Inspect the clean wound bed (re-evaluating TIME parameters).<br/>- Using sterile forceps or a non-touch technique, place the primary dressing directly onto the wound bed.<br/>- Apply secondary absorbent pad if required; secure with adhesive border or retention tape (e.g., Hypafix / Mefix).<br/>- Ensure dressing is wrinkle-free, fully seals margins, and allows joint mobility. | Critical Failure Checkpoint: Touching the wound-contact surface of the dressing with non-sterile gloved fingers. Leaving unsealed gaps that allow environmental microbial ingress. |
| Phase 8: Disposal, Decontamination & Documentation | - Discard all used swabs, drapes, and packaging into the yellow risk waste bag; seal bag.<br/>- Remove gloves, wash hands, and decontaminate trolley top with a disinfectant wipe.<br/>- Dispose of apron and perform final hand hygiene.<br/>- Ensure patient is comfortable, warm, and call bell is within reach.<br/>- Record comprehensive clinical documentation in the nursing notes and wound assessment chart: date, time, TIME parameters, exudate status, dressing products applied, pain score, signature, and NMBI Personal Identification Number (PIN). | Critical Failure Checkpoint: Leaving clinical waste unsealed on the ward. Failing to decontaminate trolley post-procedure. Documenting vague notes without specifying dressing type, exudate volume, or signature/PIN. |
3. Principles of Moist Wound Healing
For decades, traditional clinical practice held that wounds should be kept dry and exposed to air to form hard protective scabs. In 1962, landmark research by Dr. George Winter fundamentally transformed tissue viability by demonstrating that epithelialisation occurs two to three times faster in a warm, moist physiological environment than under a dry crust.
Biological Advantages of the Moist Wound Environment
- Accelerated Keratinocyte Migration: Epithelial cells require a liquid medium to migrate. In a dry wound, keratinocytes must secrete collagenases to burrow down into deeper, moist connective tissue beneath dry eschar. In a moist environment, cells glide freely across the wound surface.
- Enhanced Autolytic Debridement: Endogenous proteolytic enzymes (elastases, collagenases) and tissue macrophages function optimally in a moist, normothermic (37°C) medium, naturally liquifying slough and necrotic debris without damaging viable granulation.
- Angiogenesis & Fibroplasia: Low-tension moist environments encourage capillary endothelial budding and fibroblast proliferation.
- Preservation of Growth Factors: Wound fluid contains high concentrations of essential cytokines, PDGF, VEGF, and EGF. Moist dressings retain these physiological mediators at the tissue interface.
- Significant Pain Reduction: Exposing sensory nerve endings to air desiccation triggers intense nociceptive pain. Moist primary dressings cover and bathe exposed nerve endings, substantially alleviating discomfort.
4. Wound Dressing Categories and Pharmacodynamics
Selecting an appropriate wound dressing requires matching the physical and chemical properties of the dressing to the clinical presentation of the wound bed, depth, and exudate volume.
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| WOUND DRESSING SELECTION BY EXUDATE & TISSUE |
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| DRY / MINIMAL EXUDATE (Necrotic / Dry Slough) |
| -> DONATE MOISTURE: Amorphous Hydrogels (Intrasite Gel, Purilon) |
| -> Semi-permeable Film or Hydrocolloid cover |
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| LOW TO MODERATE EXUDATE (Clean Granulation / Epithelialisation) |
| -> MAINTAIN MOISTURE: Hydrocolloids (DuoDERM, Comfeel) |
| -> Thin Polyurethane Foams (Mepilex Lite, Allevyn Gentle Border) |
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|
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| MODERATE TO HEAVY EXUDATE (Sloughy / Cavity / Exuding Granulation) |
| -> ABSORB MOISTURE: Calcium Alginates (Kaltostat, Sorbsan) |
| -> Polyurethane Foams (Allevyn, Biatain) / Hydrofibres (Aquacel) |
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| CRITICALLY COLONISED / INFECTED WOUNDS |
| -> TOPICAL ANTIMICROBIALS: Silver (Aquacel Ag) / Medical Honey (Medihoney) |
| -> Cadexomer Iodine (Iodosorb) - *Check thyroid & renal contraindications* |
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Comprehensive Wound Dressing Selection Guide
| Dressing Class | Mechanism of Action & Composition | Primary Indications | Contraindications & Clinical Cautions | Clinical Examples |
|---|---|---|---|---|
| Alginates | Natural polysaccharide fibres derived from brown seaweed (calcium/sodium alginate). In contact with wound exudate, calcium ions exchange for sodium ions, transforming dry fibres into a soft, hydrophilic calcium-sodium alginate gel. Absorbs 15 to 20 times its dry weight in fluid. Released calcium stimulates platelet activation, providing mild hemostatic properties. | - Moderate-to-heavily exuding wounds.<br/>- Cavity wounds and sinuses (alginate ribbon/rope).<br/>- Minor bleeding wounds and donor sites.<br/>- Sloughy wounds requiring moist softening. | - Dry wounds or minimally exuding wounds (adheres to wound bed, causing desiccation and severe pain upon removal).<br/>- Third-degree burns.<br/>- Requires a secondary cover dressing. | Kaltostat, Sorbsan, Algisite M |
| Hydrocolloids | Composed of hydrophilic colloidal particles (sodium carboxymethylcellulose, gelatin, pectin) dispersed in an adhesive elastomer matrix. In contact with exudate, colloidal particles swell and form a moist cohesive gel over the wound bed. Occlusive or semi-occlusive; provides thermal insulation, waterproof barrier, and promotes autolytic debridement. | - Low-to-moderately exuding wounds.<br/>- Superficial pressure injuries (Category 2).<br/>- Minor burns, donor sites, and abrasions.<br/>- Epithelialising clean wounds. | - STRICTLY CONTRAINDICATED in clinically infected wounds (anaerobic bacteria proliferate rapidly under occlusive conditions).<br/>- Heavily exuding wounds (rapid leakage and maceration).<br/>- Diabetic foot ulcers with ischemia.<br/>- Note: Forms a yellowish, malodorous gel breakdown ("pseudopus") that must be washed away before assessing for true infection. | DuoDERM Extra Thin, Comfeel Plus, Granuflex |
| Hydrogels | Insoluble polymers (carboxymethylcellulose or propylene glycol) containing 80% to 90% water. Formulated as amorphous viscous gels or cross-linked polymer sheets. Acts as a moisture donor, rehydrating hard, dry necrotic eschar and slough to promote autolytic debridement by endogenous enzymes. Provides cooling, soothing pain relief. | - Dry, black necrotic wounds (eschar).<br/>- Dry sloughy wounds requiring rehydration.<br/>- Painful superficial wounds and radiation dermatitis.<br/>- Shallow arterial ulcers with minimal exudate. | - Heavily exuding wounds (causes severe peri-wound maceration).<br/>- Gangrenous ischemic limbs where eschar must remain dry.<br/>- Amorphous gels require a secondary retention dressing (film or foam). | Intrasite Gel, Purilon Gel, ActiformCool |
| Foams (Polyurethane) | Hydrophilic polyurethane foam with an open-cell porous structure, often backed by a semi-permeable film. Highly absorbent; manages moderate-to-heavy exudate via vertical capillary absorption while maintaining a moist wound interface. Provides thermal insulation and mechanical cushioning. | - Moderate-to-heavily exuding wounds.<br/>- Category 2, 3, and 4 pressure injuries.<br/>- Venous leg ulcers under compression bandaging.<br/>- Skin tears and lacerations. | - Dry wounds, minimal exudate, or hard dry eschar (may adhere to fragile beds).<br/>- Deep cavity wounds without primary packing (creates dead space). | Allevyn, Mepilex Border, Biatain |
| Antimicrobial: Silver | Impregnated with elemental silver, ionic silver ($Ag^+$), or nanocrystalline silver. Silver ions bind bacterial cellular wall proteins, disrupt DNA replication, and denature bacterial enzymes. Broad-spectrum bactericidal activity against Gram-positive, Gram-negative, MRSA, and Pseudomonas aeruginosa. | - Critically colonised wounds with stalled healing.<br/>- Locally infected wounds.<br/>- High-risk surgical incisions. | - Silver hypersensitivity.<br/>- Must be used under a two-week challenge protocol; discontinue once bioburden is controlled to prevent resistance and cytotoxicity.<br/>- Nanocrystalline silver forms must be removed before Magnetic Resonance Imaging (MRI). | Aquacel Ag, Acticoat, Mepilex Ag |
| Antimicrobial: Medical Honey | Formulated from standardized medical-grade Leptospermum (Manuka) honey. High osmolarity draws interstitial lymph fluid into the wound bed, creating osmotic bacterial lysis. Naturally low pH (3.5 to 4.5) inhibits bacterial proliferation and enhances tissue oxygenation. Glucose oxidase produces sustained low-level hydrogen peroxide. Deodorises malodorous wounds. | - Sloughy, malodorous wounds.<br/>- Critically colonised ulcers and acute trauma wounds.<br/>- Wounds requiring gentle autolytic debridement. | - Known hypersensitivity to honey or bee venom.<br/>- May cause temporary stinging pain due to low pH and osmotic fluid shift. | Medihoney, Activon Tube, Algivon |
| Antimicrobial: Cadexomer Iodine | 3D cross-linked starch (cadexomer) beads containing 0.9% elemental iodine. Beads absorb wound exudate, swell, and slowly release sustained bactericidal molecular iodine directly into the wound bed. Highly effective at penetrating and disrupting polymicrobial biofilms. | - Chronic, heavily exuding, sloughy wounds with confirmed critical colonisation or biofilm.<br/>- Chronic venous leg ulcers. | - STRICTLY CONTRAINDICATED in thyroid disorders (Hashimoto's thyroiditis, Graves' disease, non-toxic goitre) due to systemic iodine absorption.<br/>- Severe renal impairment.<br/>- Pregnancy, lactation, and children under 12 years.<br/>- Limit continuous treatment to maximum 3 months. | Iodosorb Ointment, Iodosorb Powder, Iodoflex |
| Film Dressings (Polyurethane) | Thin, transparent polyurethane sheets coated with a hypoallergenic acrylic adhesive. Semi-permeable: permeable to moisture vapour and oxygen, but impermeable to liquid water, bacteria, and viral particles. Allows continuous visual inspection of the wound without removal. | - Superficial epithelialising wounds.<br/>- Secondary retention dressing over gels/alginates.<br/>- Intravenous cannula insertion sites.<br/>- Stage 1 pressure injuries (friction reduction). | - Moderately to heavily exuding wounds (fluid pools beneath film, causing blister formation and severe peri-wound maceration).<br/>- Clinically infected wounds.<br/>- Fragile, thin skin (removal risks epidermal stripping). | Tegaderm, Opsite Flexigrid, IV3000 |
5. Clinical Pitfalls in ANTT & Dressing Selection
| Clinical Error in Practice | Pathophysiological Consequence | Correct Irish Nursing Action |
|---|---|---|
| Applying a hydrocolloid to a clinically infected wound. | The airtight occlusive barrier creates a warm, anaerobic microenvironment, accelerating the proliferation of virulent anaerobic pathogens (Clostridium, Bacteroides) and precipitating deep cellulitis or sepsis. | Never apply occlusive hydrocolloids to infected wounds. Select a breathable antimicrobial foam or alginate dressing combined with systemic medical review. |
| Allowing saline to splash onto sterile paper drapes. | Fluid wetting the paper drape creates a capillary bridge (strike-through contamination), immediately drawing micro-organisms from the non-sterile trolley shelf through to the sterile field. | Pour saline gently from a low height (~10 cm) directly into the gallipot; discard and re-establish any sterile drape that becomes contaminated by liquid strike-through. |
| Using dry gauze to pack an exuding cavity wound. | Dry gauze adheres to fragile capillary buds in the granulation bed. When removed, it rips away newly formed endothelial tissue, causing severe pain and setting the wound back into the inflammatory phase. | Loosely pack cavities with moist ribbon gauze, calcium alginate rope, or hydrofibre ribbon, ensuring dead space is eliminated without packing under high tension. |
| Prescribing Cadexomer Iodine without checking thyroid history. | Systemic absorption of molecular iodine can precipitate severe thyrotoxicosis, thyroid storm, or profound hypothyroidism in patients with pre-existing thyroid abnormalities. | Thoroughly review the patient's medical history and medication kardex before applying iodine; verify normal thyroid function tests (TFTs) and absence of goitre. |
Test Your Knowledge
During an RCSI OSCE station demonstrating a standard ANTT dressing change on a surgical wound, which candidate action constitutes an immediate critical error (Not Yet Competent) in aseptic technique?
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Test Your Knowledge
A patient has a chronic, dry, hard black necrotic eschar on the left posterior heel with no surrounding erythema, fluctuance, edema, or malodour. An ankle-brachial pressure index (ABPI) is pending due to severe peripheral arterial disease. According to Irish tissue viability principles, what is the most appropriate management approach for this heel wound?
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Test Your Knowledge
A 74-year-old female with a heavily exuding, sloughy venous leg ulcer has signs of critical colonisation and delayed healing. The nurse considers using a cadexomer iodine paste dressing to reduce bioburden and break down biofilm. Which condition in the patient's medical history represents an absolute contraindication to this dressing?
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D