Lesson 28 - Wound Management

What degrees of contamination apply to surgical wounds only?

1. clean

2. clean-contaminated

What degrees of contamination apply to surgical and traumatic wounds?

1. contaminated

2. infected (dirty)

What is a Class I/Clean wound?

1. uninfected operative wound with no inflammation that does not enter the respiratory, alimentary, genital, or uninfected urinary tract

2. no break in aseptic technique

What is a Class II/Clean-Contaminated wound?

operative wound in which the respiratory, alimentary, genital, or urinary tract are entered without unusual contamination

What is a Class III/Contaminated wound?

1. open, fresh, accidental wounds

2. operations with major breaks in sterile technique

3. operations with gross spillage from the GI tract

4. incisions with acute or no purulent inflammation

What is a Class IV/Dirty-Infected wound?

old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera

What are some examples of clean surgeries?

skin incision, mass removal, exploratory laparotomy, ovariohysterectomy, castration

What is the infection rate for clean surgeries?

0-6%

What are some examples of clean-contaminated procedures?

enterotomy, cholecystectomy, placement of a drain in an otherwise clean wound

What is the infection rate for clean-contaminated surgeries?

4.5-9%

What is the infection rate for contaminated wounds?

6-28%

What actions should you take with contaminated wounds?

1. Antibiotic prophylaxis

2. lavage

3. +/- debridement (wounds)

What traumatic wounds are considered contaminated?

<12 hours post-wounding

What traumatic wounds are considered infected (dirty)?

>12 hours post-injury or overtly infected

What actions should you take with infected (dirty) wounds?

1. Antibiotics

2. Lavage

3. debridement

4. drainage

5. +/- wet-dry bandages

What is the first step to approaching a traumatic wound?

initial patient assessment (ABCs)

What is the second step to approaching a traumatic wound?

wound assessment

What is the third step to approaching a traumatic wound?

wound cleansing and debridement

What is the fourth step to approaching a traumatic wound?

+/- surgical intervention

What is the fifth step to approaching a traumatic wound?

wound management plan

What should be determined in the wound assessment step?

1. type of wound

2. location, proximity to vital structures

3. degree of contamination

4. assess for trauma to deeper tissues (ex. fracture)

5. +/- culture & susceptibility of wound (consider macerated tissue culture)

What is the "golden period" of traumatic wounds?

first 6-8 hours between contamination at injury and bacterial infection (>105 bacteria per gram of tissue)

What decision does the golden rule impact?

decision to close the wound

What is the goal of wound cleansing?

reduce bacterial contamination and remove gross contaminants and necrotic debris from within the wound

How do you clean a wound?

1. Wide clip of hair around wound

2. Aseptically prepare area around wound

3. Lavage or irrigate wound with copious amounts of warmed solution

What is a trick for avoiding hair in the wound when clipping?

use aqueous sterile lubricant or oiled clipper blades

What can you use to lavage and irrigate a wound?

1. Saline (NaCl 0.9%, isotonic)

2. Lactated Ringers Solution (LRS, isotonic)

3. Tap water (hypotonic)

4. Dilute antiseptic solutions [CHX, P-I]

What kind of solution is ideal for wound lavage?

isotonic

When should chlorhexidine be used for lavage?

only early in wound management

What form of chlorhexidine is used for wound lavage?

solution formulation (not scrub) at an appropriate concentration for wounds

What antiseptics are used in wound management?

1.chlorhexidine 0.05% solution

2. povodone-iodine 0.1-1% solution

3. hydrogen peroxide

How does chlorhexidine work for wound management?

1. Synergistic antibacterial effect when combined with TrisEDTA

2. Residual activity (up to 48 hrs)

What can be resistant to chlorhexidine?

some strains of Pseudomonas spp.

How does povidone-iodine work for wound management?

1. Broad spectrum of activity

2. Free iodine inactivated by organic debris

3. No significant residual activity

How does hydrogen peroxide work for wound management?

1. Effective sporocide → use when possible exposure to Clostridium spores

2. Less effective antiseptic compared to CHX & P-I

3. Effervescent action dislodges bacteria & debris

What is a downside to using hydrogen peroxide for wound management?

cytotoxic especially to new capillaries

How should povidone-iodine be diluted?

the color of tea

What is true of all antiseptics at high concentrations and/or with prolonged use?

cytotoxic and can cause delayed wound healing

What is the goal of wound debridement?

remove non-viable tissue from wound

Which antiseptic should be used in a purulent or necrotic wound?

1. chlorhexidine

2. hydrogen peroxide

Which antiseptic should be used in a potential exposure to Clostridium tetani?

hydrogen peroxide

Which antiseptic should be used in a periorbital wound or surgical procedure?

povidone-iodine

Which antiseptic should be used in an orthopedic procedure?

1. povidone-iodine

2. chlorhexidine can be used but is not ideal

Why is chlorhexidine not ideal for orthopedic surgeries?

potential for pseudomonas resistance

Which antiseptic should be used in an abscess?

1. chlorhexidine

2. povidone-iodine but not ideal

3. hydrogen peroxide

Why is povidone-iodine contraindicated in abscesses?

inactivated in organic material

How can non-viable tissue affect wound healing?

1. Increase risk of infection (anaerobic bacteria)

2. Delay wound healing

What are some tips for successful wound debridement?

1. May use multiple methods of debridement for the same wound

2. Wounded tissue may take days to "declare" itself (~48 hours)

What are the methods for wound debridement?

1. surgical

2. mechanical

3. hydrodynamic

4. biosurgical

5. enzymatic

6. autolytic (moist)

What is mechanical wound debridement?

wet-dry, dry-dry dressings and non-selective debridement

What is hydrodynamic wound debridement?

pressure irrigation

What is biosurgical wound debridement used for?

chronic, non-healing wounds

What is enzymatic wound debridement?

breaks down necrotic tissue and liquefies coagulum

What is autolytic (moist) wound debridement?

use hydrophilic, semi- or occlusive dressings

mechanical wound debridement

hydrodynamic wound debridement

biosurgical wound debridement

enzymatic wound debridement

autolytic wound debridement

How can surgical wound healing be classified?

stage of wound healing when the wound is closed

What does the type of wound healing depend on?

if the wound is closed or left to heal on its own

What type of wound closures heal with 1st intention?

1. primary closure

2. delayed primary closure

What type of wound closures heal with 2nd intention?

secondary closure

What phase of wound healing are primary and delayed primary closure wounds in?

inflammatory phase

What phase of wound healing are secondary closure wounds in?

repair phase (granulation tissue present)

What is primary closure of a wound?

wound repair within 24 hours of injury

What is primary closure indicated for?

1. clean surgical wound

2. contaminated traumatic wounds that are rendered clean

What is delayed primary closure?

wound repair within 5 days of injury before granulation tissue forms

What is delayed primary closure indicated for?

mild to moderately infected wounds (control infection before closing wound)

What is 2nd intention wound healing?

allow the body to heal the wound

What are the indications for 2nd intention wound healing?

1. wound too large to close surgically

2. affected area not amenable to surgery

3. heavily infected wound

4. surgical repair not an option (budget, anesthesia concerns, logistics)

What are the potential complications of 2nd intention wound healing?

potential complications: contracture, proud flesh (horses), delayed wound healing

What is secondary closure?

wound repair after granulation tissue formation

What are the steps to secondary closure?

1. "Freshen" wound edges

2. "Undermine" wound edges

3. Use tension relieving sutures and techniques if necessary

4. +/- place drain

What are the potential wound management plans?

1. Therapeutics

2. Bandages

3. Tetanus prevention (+/-)

4. Drains (+/-)

5. Skin grafting (+/-)

What are the different therapeutics you can use?

1. antibiotics (topical or systemic)

2. topical wound enhancers

3. analgesics like topical (lidocaine/bupivacaine), systemic (NSAIDs, opioids, gabapentin)

What are the benefits of moist wound healing?

1. Supports proliferation & migration of cells essential for wound healing processes

2. Supports production of cytokines & growth factors essential for wound healing

3. Prevents dehydration of wound bed & desiccation of cells critical to healing (fibroblasts, keratinocytes, inflammatory cells)

4. Prevents scab formation (scabs can trap unwanted bacteria and debris at wound site)

5. Allows for optimal balance in the stages of wound healing

6. Decreased pain (versus dry wounds which are irritated, more inflamed and have higher risk for infection)

7. Faster re-epithelialization

8. Reduced risk of infection (due to healthy balance of immune and other cells essential to wound healing)

9. Reduced scar formation

What are the layers of a modified robert jones bandage?

1. Contact (Primary) - also referred to as the wound dressing

2. Intermediate (Secondary)

3. Outer (Tertiary)

What are the functions of the contact (primary) layer of a wound dressing?

1. Debride (necrotic wounds)

2. Deliver topical medication

3. Absorb wound exudate

4. Protect granulation tissue (non-adherent only!)

What are the two basic types of contact (primary) layer of a wound dressing?

adherent and non-adherent

What are the indications for absorbent wound dressing?

open contaminated and infected wounds with exudate

What are the indications for adherent wound dressing?

necrotic wounds

What are the indications for non-adherent wound dressing?

1. ALL non-necrotic wounds particularly once granulation tissue has begun to form

2. Surgical wounds

What are the characteristics of an adherent layer?

1. Wicking action occurs as gauze dries and debris and exudate is absorbed into gauze

2. Wet dressings absorb faster than dry and have less wound dessication

3. Can use saline, hypertonic saline, 0.05% chlorhexidine

What is important about mechanical debridement?

non-selective and painful

What are the indications for using an adherent layer?

open wounds in need of debridement

What are some tips of successful contact layers?

1. discontinue as soon as debridement has been achieved

2. never use in the presence of granulation tissue

What kind of contact layer can be used in all wound types?

non-adherent

What is the function of non-adherent dressing?

help to retain moisture at wound site to promote moist wound healing

What will the frequency of dressing change depend on?

wound type and stage of wound healing

What is the function of the intermediate (secondary) layer?

1. Absorbent

2. Provides padding

3. Holds contact layer in place

4. Stabilizes & decreases movement (orthopedic bandage - depends on thickness of the layer)

What are the materials for an intermediate (secondary) layer?

1. cast padding

2. cotton wool wound

What is the function of the outer (tertiary) layer?

1. Protection

2. Stability

3. Holds other layers

How many layers are in the outer layer?

two (inner and outer)

What are the materials for an inner layer of the outer (tertiary) layer?

conforming bandage

What are the materials for an outer layer of the outer (tertiary) layer?

elastic adhesive tapes (Vetrap®, Elastikon®)

What is the order of most to least susceptible to tetanus?

equine, lamb, man > ruminants, swine > cat, dog

What is dead space?

abnormal space between tissue layers where blood and/or serum may accumulate

What are the techniques to manage dead space?

1. Suture obliteration

2. Compression bandage

3. Drainage

What are the indications for drains?

1. infection

2. dead space/seroma

3. body cavity effusions