Exam 2: Wound Management

phases of wound healing

• inflammation

• debridement

• maturation 

gross and microscopic aspects of inflammation

• clot, exudate, denuded surface

• clot,fibronectin and factor XIII, early ECM, scab to protect the wound

aspects of debridement phase 

• granulation tissue variable 

• contraction 

• epitthelialization 

• neutrophil activity

• fibrinogen to fibrin 

• monocytes migrate in 

• ECM matures 

• multitude of factors 

aspects of maturation 

• epithelialize 

• contraction 

• reorganize collagen 

• strength increases 

• reduction in collagen, cellular content, vascular content 

wound classification

• clean

• clean-contaminated

• contaminated

• dirty or infected

types of debridement

• sharp

• hydrodynamic

• mechanical

• enzymatic

nonselective debridement methods 

• mechanical = bandaging 

• hydrodynamic= hydrotherapy/pulsed lavage 

• chemical = hydrogen peroxide, iodine, chlorhexidine 

selective debridement

• enzymatic

• surgical mechanic

• autolytic- moisture retentive topical therapy

• biological = maggots

generally describe mechanical debridement

• serial removal of loss/devitalized tissue

• gauze sponges/forceps and scissors

• in conjunction with hydrotherapy

• time consuming, often has a non-selective component

how do you pick what tissue to mechanically debride? 

• if its dead, its dead! 

• scalpel or scissors with limited or no use of laser or electroscalpel 

• dead tissue= green, black, brown, grey 

bandaging after mechanical debridement

• wet to dry or dry to dry

• change daily or twice daily

• inexpensve

• useful for large areas

• traumatic to delicate tissues, slow

describe the order of conservative for mechanical debridement

• subq

• skin

• muscle/fascia

• tendon

• blood vessels

• nerves

pros and cons of enzymatic debridement 

• removal of necrotic tissue early after injury without removal or viable tissue, decreases blood loss, elimination of multiple aesthetic/surgical episodes 

• other forms of debridement are necessary, must be <15% otal body surface area 

medications for enzymatic debridement

• granulex = trypsin = clots, pyogenic membranes, necrotic tissue

• santyl= collagenase = no effect on keratin, fat and fibrin

generally describe hydrodynamic debridement

• saline, LRS, plasmalyte

• 7-10psi

• volume- more is better but not always

why is pressure so important for hydrodynamic debridement 

• too high = damage tissue, drive bacteria and debris deeper 

• just right 7-8psi

• too low is ineffective

methods for assessing tissue viability 

• attachment 

• color 

• texture 

• temperature 

• sensation 

• bleeding 

eschar

• dry necrotic tissue

• adrk, firm and leathery

• ± remove

slough

• moist necrotic tissue

• yellow/grey, wet, stringy

• remove

fibrous coating 

• yellow, gelatinous 

• do not remove 

when is closure appropriate?

• healthy wound bed!

• stable animal

• viable tissue

• no contamination

• zero to minimal tension

important general concepts of wound closure

• gentle tissue handling

• aseptic technique

• meticulous hemostasis

• minimal tension

• tissue apposition

• minimize dead space

• preserve vascular supply

adjustable horizontal mattress suture 

• intradermal suture 

• placed in continous horizontal pattern without throws on either end 

• lead split shot sterilied 

options for subdermal plexus flaps

• Z plasty

• V to Y plasty

• pedicle advancement flap- single or bipedicle

• skin fold flap

undermining

• at the level of muscle or fascial plane, deep to cutaneous trunci

• DEAD SPACE- drains and sutures

• elasticity is key

walking suture 

• aids in movilization of skin 

• suture should incorporate the epidermis 

• “bite” into wound bed nearer to the center of wound- granulation tissue and underlying fascia

pros and cons of walking suture

• advance skin, obliterate dead space, alievate tension

• increases suture use, temporarily affixes skin to underlying tissue, vascular injury, multiple areas of dead space

basic principles of closing defects

• undermining

• find the corners or consider the circle s square

• suture inward

• interrupted suture pattern

types of flaps 

• subdermal plexus flaps 

• single pedicle 

• bipedicle flaps 

• axial pattern flaps 

flap length to width ratio for single pedicle advancement flaps

2:1 or at most 3:2

rotational flap

• similar principle to a basic, single pedicle advancement but with rotational advancement

• incise beginning at the short portion of the triangle

axial pattern flaps 

• a direct cutaneous artery supplies a specific area of skin - angiosome 

• may provide significant coverage 

• robust tissue 

• care must be taken with tension 

describe skin grafting

• place on healthy granulation bed! Must be healed to a certain level

• cut graft longer than needed

• lengthen slits to increase width

• cut graft into that syrofoam webbing that goes around some fruits

kinds of contact or primary layers

• absorptive = calcium alginate, hypertonic saline, copolymer starch

• moisture retention= polyurethane foam/film, hydrocolloid, hydrogel

• semiocclusive= petrolatum/antimicrobial coated

• honey or sugar

calcium alginate 

• transition from inflammatory to repair 

• 20-30x its weight 

• Na+ exchange for Ca++ serum derived peptide growth factor in higher concentration, promotes granulation tissue, future potential for drug and factor delivery, entraps bacteria, may allow less frequent changes 

• sensitive areas may tingle or skin, may dehydrate wound or form eschar

• DO NOT USE IN WOUNDS WITH >25% NECROTIC TISSUE 

hydroactive substances Ca alginate and Copolymer starch

• polymers or gels capable of absorbing large amounts of fluid

• moist environment

• supports autolytic debridement

• promotes granulation tissue

• Ca alginate provides hemostasis

• may produce foul odor and appearance

polyurethane foam

• necrotic wounds that need autolytic debridement

• moist environment absorbs exudate or provides moisture, not brilliant for debridement

• most often used in NPWT

advantages and diaadvantages of foam dressings 

• considerable amounds of serous exudate, moist wound environment, medication delivery, promotes granulation and epithelialzation, changes 3-7 days 

• may adhere if becomes dry, may requir adhesive 

polyurethane FILM 

• minimal exudate and allows visualization 

• moist environment that allows water vapor escape, not brilliant for debridement 

• most often in conjunctive with hydrocolloid 

• care not to cause maceration 

• not to be used on exposed muscle, tendon, bone, or 3rd degree burns 

advantages and disadvantages hydrocolloids

• accelerates epithelialization, moist environment, barrier to water and external bacteria

• resultant gel is tenacious, not useful with large amounts of exudate, wound bacterial counts are increased, may delay wound contraction

hydrogel

• soothing, conforms to wound, less tenacious gel as compared to hydrocolloids,c hange every 2-4days

• excessive granulation tissue, not in infected wounds, maceration may occur

vaseline as a contact layer 

• minimizes tissue injury 

• mesh size important in petrolatum coated, petrolatum may slow epithelization 

semiocclusive pads

• minimizes tissue damage

• may still adhere, requires frequent changes, viscous exudate may not be able to escape, may require adhesive surrounding wound edge

honey as a contact layer

• variety of Gm + and Gm - organisms

• decreases edema

• energy source

• sloughing of dead tissue

• unpasturized and ell lavaged

• care for large wounds due to hydrophilic properties

sugar as a contact layer 

• reduces edema 

• attracts macrophages 

• energy source 

• slough of dead tissue 

• protection and promotes granulation 

VAC therapy

• vacuum assisted closure

• negative pressure wound therapy

• topical negative pressure

fluid based mechanism of VAC therapy

• negative pressure decreases interstitial pressure and reopens capillaries in or around the wond, increasing blood flow

• fluid removal or both positive and negative wound factors

mechanical mechanism of VAC therapy 

• viscoelestic tissue responds to deformation by stretching and increasing mitotic rate 

• cells stretch alters ion permeability, 2nd messenger release, gene expression 

• shear stresses activate growth factors and kinases 

VAC therapy and granulatio tissue

• inccreases rate of granulation tissue formation than wet to dry