Week 11: Irrigation and Physical Agents in Wound Management

Wound Irrigation

The use of fluids, typically saline, to remove dressing residue, devitalized tissue, topical agents, and surface bacteria from a wound bed.

Irrigation vs. Wound Cleansing

Irrigation is targeted fluid delivery to remove contaminants; cleansing is a broader term encompassing any wound‐cleaning method.

Standard of Care for Irrigation

Every wound should be irrigated after dressing removal to prevent debris accumulation and infection.

Irrigation Fluid Choice

Selection between saline and tap water based on availability, cost, and infection risk (tap water shows no added infection risk).

Irrigation Goal

Remove necrotic tissue and debris without traumatizing the wound bed.

Safe Irrigation Pressure

4–15 PSI is considered effective and atraumatic for wound irrigation.

High Irrigation Pressure Warning

15 PSI may damage tissue and should be avoided.

Bulb Syringe PSI

Delivers approximately 4 PSI, often regarded as rinsing rather than true irrigation.

Angiocath Irrigation System

A 35-mL syringe coupled with a 19-gauge catheter producing 4–15 PSI for controlled irrigation.

Pressurized Saline Canister

Pre-filled container delivering pressurized saline; useful but can be messy and needs fluid collection.

Waterpik for Wounds

Dental irrigator set on low (≈6 PSI) adapted for wound irrigation when other devices unavailable.

Pulsed Lavage

Hand-held device delivering irrigation (4–15 PSI) with simultaneous suction to evacuate fluid and contaminants.

Typical Clinical PSI for Pulsed Lavage

8 PSI is most commonly applied in practice.

Pulsed Lavage Suction Benefit

Creates negative pressure that removes irrigant and pathogens directly from the wound.

Granulation Enhancement by Lavage

Controlled suction and irrigation may stimulate granulation, epithelialization, and perfusion.

Tunneling/Undermining Suitability

Pulsed lavage reaches and cleans wounds with tunneled or undermined areas effectively.

Lavage Contraindication – Exposed Deep Tissue

Avoid pulsed lavage in wounds exposing organs, vessels, or body cavities to prevent injury.

Pulse Lavage Anticoagulant Precaution

Use caution with pulsed lavage in patients on blood thinners due to bleeding risk.

PPE for Pulsed Lavage

Face shield, mask, fluid-proof gown, shoe covers, gloves, and hair cover to protect against splash.

Room Requirements for Lavage

Private, ventilated room with walls/door; exclude visitors and cover nearby items.

Whirlpool Debridement

Non-selective mechanical debridement using agitated water to remove necrotic tissue.

Whirlpool Temperature Range

Maintain 92–102 °F to ensure patient comfort and safety.

Whirlpool Treatment Time

Typically 10–20 minutes per session.

Jet Direction Precaution

Jets should not be aimed directly at the wound to minimize tissue trauma.

Whirlpool Chemical Additives

Dilute agents like chloramine, chlorostat, or bleach may be used but are cytotoxic; reserve for heavily infected wounds.

Whirlpool Contraindication – Venous Insufficiency

Avoid whirlpool for venous insufficiency or edematous limbs due to fluid overload risk.

Whirlpool Contraindication – DVT

Do not immerse limbs with acute thrombophlebitis or DVT to prevent embolization.

Electrical Stimulation for Wounds

Application of electrical currents to enhance healing through cellular migration and proliferation.

High-Volt Pulsed Current (HVPC)

Common electrical modality delivering twin-peaked monophasic pulses for wound therapy.

Galvanotaxis

Directional movement of cells in response to an electric field, central to e-stim wound mechanisms.

E-stim Cell Migration

Electric fields attract neutrophils, macrophages, fibroblasts, and keratinocytes to the wound.

E-stim Bactericidal Effect

Electrical currents can reduce bacterial load within the wound bed.

Autolytic Debridement Facilitation

E-stim promotes endogenous enzymes that liquefy necrotic tissue.

Restoring Wound Polarity

Using cathode (-) initially to counteract wound’s positive charge and attract positive cells.

Cathodic Parameters

100–128 pps, 100–150 V, 60 min, 5–7×/week during inflammatory phase.

Anodic Parameters – Granulation

100–128 pps, 100–150 V, 60 min, 5–7×/week to stimulate proliferation.

Anodic Parameters – Epithelialization

60–64 pps, 100–150 V, 60 min, 3–5×/week for re-epithelial phase.

E-stim Indication – Stage III/IV Pressure Ulcer

Beneficial for chronic deeper pressure injuries unresponsive to standard care.

Medicare 30-Day Rule

Conservative wound care must precede e-stim for 30 days before reimbursement.

Pacemaker Contraindication

E-stim should not be applied over or near implanted pacemakers.

Untreated Osteomyelitis Contraindication

Active bone infection precludes electrical stimulation therapy.

Metal Ion Dressing Precaution

Dressings containing silver or zinc can alter current flow; remove before e-stim.

Negative Pressure Wound Therapy (NPWT)

Sealed foam dressing connected to a vacuum pump to apply sub-atmospheric pressure.

Macrostrain in NPWT

Visible wound edge approximation and fluid removal generated by negative pressure.

Microstrain in NPWT

Microscopic cell deformation stimulating proliferation, angiogenesis, and granulation.

NPWT Exudate Removal

Continuous suction evacuates fluids and infectious material from the wound bed.

NPWT Indication – Venous Leg Ulcer

Useful for chronic venous wounds with moderate to heavy drainage.

NPWT Cleanliness Requirement

Wound must be at least 80 % free of necrotic tissue before NPWT initiation.

NPWT Typical Pressure

50–175 mmHg, with optimal blood flow increase observed at 125 mmHg.

NPWT Dressing Change Interval

Every 48–72 hours to maintain seal and cleanliness.

NPWT Continuous Mode

Most common setting providing uninterrupted negative pressure.

NPWT Contraindication – Exposed Organs

Foam must not contact blood vessels, organs, or nerves directly.

NPWT Contraindication – Malignancy

Cancerous tissue in wound bed rules out NPWT use.

NPWT Precaution – Anticoagulants

Monitor bleeding risk in patients on blood-thinning medications.

Foam Cutting for NPWT

Foam trimmed to fit wound dimensions; should not rise above skin surface.

Transparent Film Seal

Adhesive drape creating airtight barrier over NPWT foam.

Ultrasound for Wound Healing

Use of sound waves to stimulate tissue repair through mechanical and thermal effects.

Collagen Deposition Increase

Therapeutic ultrasound promotes fibroblast activity leading to stronger matrix.

Angiogenesis Enhancement

Ultrasound can stimulate new blood vessel formation in the wound region.

Scar Pliability Improvement

Continuous ultrasound aids remodeling of restrictive immature scars.

Low-Frequency Ultrasound

25–40 kHz ultrasound used primarily for debridement and bioburden reduction.

Saline Mist Medium

Aerosolized saline employed to transmit low-frequency ultrasound energy.

Low-Frequency US PPE

Protective clothing required due to aerosol generation during treatment.

Low-Frequency US Dosage

20–60 s/cm² or minimum 4 min for wounds <16 cm², 2–3×/week.

Superficial Wound Frequency

3 MHz ultrasound targets tissues 1–2 cm deep.

Deep Wound Frequency

1 MHz ultrasound penetrates 3–5 cm for deeper lesions.

Pulsed Ultrasound Intensity

0.5–1.0 W/cm² for non-thermal effects during acute phases.

Continuous Ultrasound Intensity

Up to 1.5 W/cm² applied to assist remodeling in closed wounds.

Ultrasound Zone Concept

Area treated equals 1.5 × the transducer head; 2–3 min per zone.

Ultrasound Treatment Frequency

Administer 2×/day to 3×/week depending on stage and goals.

Hydrogel Coupling Medium

Water-based gel ensures efficient ultrasound energy transfer.

Hyperbaric Oxygen Therapy (HBO)

Breathing 100 % oxygen at >1.5 ATA in a chamber to enhance tissue oxygenation.

Plasma Oxygen Increase

At 2 ATA, oxygen dissolved in plasma rises ~14-fold, aiding ischemic tissue.

Transcutaneous Oxygen Monitoring

Measures skin oxygen (TcPO₂) to predict healing potential and HBO benefit.

Normal TcPO₂

≈50 mmHg in healthy skin.

Healing TcPO₂ Threshold

40 mmHg generally supports normal wound repair.

Supportive TcPO₂ Range

≥35 mmHg indicates possible benefit from HBO.

Poor Prognosis TcPO₂

HBO Session Parameters

Chamber at 1.5–2.5 ATA, 90–120 min, 2×/day to 3×/week, 10–60 sessions.

HBO Indication – Wagner Grade 3 Ulcer

Approved for deep diabetic foot ulcers with bone involvement or abscess.

HBO Contraindication – CHF

Congestive heart failure can worsen under hyperbaric conditions.

HBO Contraindication – Claustrophobia

Severe anxiety inside chamber may preclude therapy.

HBO Contraindication – Pregnancy

Potential fetal risks make HBO inadvisable during pregnancy.

HBO Contraindication – Severe Arterial Insufficiency

Critical ischemia often requires revascularization before HBO.

HBO Cost

Estimated $37,000–$75,000 for a full treatment course.

Ultraviolet C (UVC)

200–290 nm wavelength light with germicidal properties; limited wound research.

UVC Germicidal Action

Destroys bacterial DNA, reducing bioburden in critically colonized wounds.

UVC Vascular Permeability Increase

May enhance local blood flow and cell turnover in the wound.

UVC Short-Term Use

Recommended briefly for Stage III/IV ulcers to lower microbial load.

Monochromatic Infrared Energy (MIRE)

Delivers 890 nm near-infrared light via flexible pads; claims 400 % circulation boost.

MIRE Evidence

Research minimal; most studies sponsored by manufacturers.

Low-Level Laser Therapy (LLLT)

Uses photonic energy to purportedly stimulate healing and improve scar strength.

LLLT Research Status

Mostly animal studies; requires more robust clinical trials.

Research Challenge – Comorbidities

Patient health conditions complicate wound-care study outcomes.

Research Challenge – Adherence

Variability in patient compliance hampers consistent data collection.

Research Challenge – Sample Size

Small cohorts limit statistical power and generalizability in wound studies.

Clinically vs. Statistically Significant

Outcome may be statistically different yet lack meaningful patient impact.

Manufacturer-Sponsored Bias

Companies may underreport negative findings, skewing literature favourably.

Clinical Decision Matrix

Tool matching wound presentation (granular/necrotic, draining/non-draining) to suitable modalities.

Granular + Draining Modalities

Pulsed lavage with suction, whirlpool, e-stim, low-frequency US, possible HBO.