Four Phases of Wound Healing
Inflammatory
Debridement
Repair
Maturation
Inflammatory Phase
Blood fills the wound to clean the surface
Vasoconstriction slows hemmorrhage
Vasodilation leaks fluid with clotting factors
Blood clot forms to stabilize the wound edges
Debridement Phase
Begins about 6 hours after injury
Neutrophils and macrophages appear in the wound to remove necrotic tissue, bacteria and foreign material
Repair Phase
Begins after the blood clot has formed and necrotic tissue and foreign material has been removed
Active for 3-5 days - "lag phase"
Invasion of fibroblasts to produce collagen that matures into scar tissue
Proud Flesh
Overabundance of granulation tissue
Repair Phase
Significant increase in wound strength
New capillaries appear
Capillaries and fibroblasts and fibrous tissue create granulation tissue
Granulation tissue forms after 3-5 days under the scab followed by wound contraction
Maturation Phase
Final phase of healing
Wound strength increases to the maximum level
The number of capillaries decrease, causing the scar to pale
Can continue for several years
Factors That Affect Wound Healing - Host Factors
Old Animals
Malnourishment
Hyperadrenocorticoidism
Diabetes mellitus
Liver disease - clotting factor deficits
Renal disease
Factors That Affect Wound Healing - External Factors
Foreign material in wound
Bateria
Tight bandages
Movement
Drugs
Radiation
Chemotherapy
Steroid therapy
Anti-inflammatory
Aspirin therapy
Wound Management - Immediate Care
Cover with a clean dry bandage until the patient is stabilized to prevent contamination and reduces hemorrhage
Add a water-soluble antibiotic ointment to keep the wound moist and reduce bacteria
Don't use antibiotic creams or powders as they will delay th
Wound Management - After Stabilization
Remove the bandage
Pack the wound with sterile gauze or KY jelly
Make a temporary closure using suture or towel clamps
Wound Management - Clip and Prep
Dip scissors in mineral oil to clip hair around the wound to prevent hair from contaminating the wound
Wound Management - Lavage
Removes debris, loose particles and tissues to reduce bacteria
Use moderate pressure - 35cc syringe (18-19 gauge needle) or a Water Pik
Don't add antibiotics to the lavage fluid, it will damage the tissue
Wound Management - Debridement
Removes all contaminate tissue and foreign material
Can be performed surgically by excisingt he tissue in layers
En Bloc - complete excision, small wounds
Enzymatic - can delay healing
En Bloc Debridement
A term meaning "in one piece." In surgery, it describes the technique of removing tissue.
Enzymatic Debridement
removal of damaged tissue and cellular debris from a wound or burn using nonirritating, nontoxic agents that liquefy necrotic tissue.
Wound Closure - Factors in Decision Making
Time since the injury
Degree of contamination
Degree of trauma
Blood supply to area
Patient physical status
Location of the wound
Wound Closure - Primary
First Intention Healing
Fresh clean wounds
Minimal trauma
Minimal contamination
Treated within 6-8 hours "golden period"
Includes surgically created wounds
Wound Closure - Contraction
Second intention
Wound heals surgical closure
Wound Closure - Secondary
Third Intention
Closure after 3-5 days
Granulation tissue has already developed
Severely contaminated wounds
Severely traumatized
Requires considerable debridement
Wound Closure - Abrasions
Exposure to the deep dermis
Keep the surface moist and protected
Change the bandage every 3-4 days
Burns
Fire
Cage Dryers
Heating pads
Hot liquid spills
Electrical cords
Over 50% burned, the animal rarely survives
Burns are prone to infection
Wound Closure - Burns
Manage as an open wound
Repeated debridement is required
Change the bandage often
Don't coat with lotions or salves (No oil based products)
Pain medication is often required
Degloving
removal of the skin and deep tissue from its underlying structures
Skin necrosis 3-5 days post injury
Second intention healing
Wound Care - Bandaging Purpose
Promotes wound healing
Protects from additional trauma and contamination
Immobilize the wound
Minimize post-op edema
Absorbs exudate
Lift away foreign material
Prevents CO2 loss, creating an acidichealing environment
Increase O2 availability to the wound,
Bandage Review - Layers
At least 3 - Primary (adherent), Secondary (padding), Tertiary (Conforming, protective)
Bandage Review - Most important part before cast padding?
Stirrups
Bandage Review - Robert Jones
Temporary immobilzation of fractures distal to the elbow or stifle
One joint above and one joint below
Splinting Materials
Tongue depressors (small animal)
Aluminum splints
Cast material
Thermoplastics
Splinting Prurposes
Temporary immobilization of certain fractures
Support traumatized distal limb
Should be well padded to prevent pressure points
Always placed on the caudal aspect of the limb
Ehmer Sling
Specifically to immobilize a hind limb
Prevents weight bearing
After luxation
Internally rotates and adducts the coxofemoral joint
Minimal padding is suggested
Usually applied with adhesive tape alone to prevent slippage
Velpeau Sling
Holds the flexed forelimb
Prevents movement in all joints
Luxation reduction
Scapular fractures
Luxation
displacement or misalignment of a joint or organ
Carpal Flexion Sling
Immobilize the carpus
Maintains flexion after tendon repair
Relieves tension on flexor tendons
Permanent contracture of the carpus is a possible complication
Casting
Cast material is applied instead of a tertiary layer
Extends one joint above and below
Minimal padding is suggested to prevents cast loosening and prevents movement and excessive compression
Monitor weekly
Casting Materials
Fiberglass (preferred) - Lightweight, extremely rigid, rapid setting time, ventilation, waterproof
Cast Monitoring
Inpatients - Daily
Outpatients - weekly
Check Toes for - Warmth, color, swelling
Check for - foul odor, chafing
Protect from dirt, but don't leave protective cover on for more than 30 minutes, it prevents the cast from breathing and allows the tissue to b
Suture Removal
Timing - normally 10-12 days after surgery, depending on suture material used
Examine skin before removal, skin should not be red or swollen
Use Suture scissors to remove
Staple Removal
Timing - normally 10-12 days after surgery, depending on suture material used
Examine skin before removal, skin should not be red or swollen
Special tool is required for staple removal
Protective Cone
Most important part of protecting a wound
When cast padding a bovine lower limb, what special technique is used to reduce pressure sore formation at the dewclaws?
Placing a pad of orthopedic felt with holes cut out to fit the dewclaws reduces the formation of pressure sores.
The metacarpal or metatarsal region of the equine leg?
The cannon
Natural material that absorbs fluid, and is useful for highly exudative wounds?
Hydrocolloid
What wounds are characterized by sharply incised edges with minimal tissue trauma?
Lacerations
What sling prevents weight bearing in the hind limb?
Ehmer
Common causes of burns in an animal hospital
Cage dryers, heat lamps, fire, spillage, prolonged contact with heating pads, electrical cords, hot asphalt
Has a higher tonicity than that of living cells
Hypertonic
Relating to the opposite side
Contralateral
Used most frequently to provide maximum support and immobilization externally
Cast
Synthetic hormones that depress all phases of wound healing
Corticosteroids
Produced by fibroblasts that mature into fibrous scar tissue?
Collagen
Bandages indicated for granulating wounds that are minimally to moderately exudative?
Hydrocolloid
Exuberant granulation tissue in horses, especially on the distal limbs?
Proud Flesh
Most frequently used material for casts?
Fiberglass
The phase of wound healing that is characterized by an influx of neutrophils and monocytes?
Debridement
The presence of microbes on the surface of an inanimate or living object?
Contamination
An apparatus to prevent quadricep contracture after a distal femoral fracture repair in young animals?
90-90 flexion sling
Semipermiable dressings allow air transfer but is impermeable to what?
Fluids
Phase of wound healing that can last years?
Maturation
Dressing that is impermeable to both air and fluid?
Occlusive
An open wound that developes over a bony protuberance, resulting from the compression and necrosis of the skin and soft tissues.
Decubital Ulcer
A method of debridement that involves trypsin products to dissolve necrotic tissue?
Enzymatic Debridement
Healing by contraction and epithelization
Second Intention Healing
Partial thickness wounds of the epidermis with exposure of the deep dermis
Abrasions
The modified fibroblasts present in granulation tissue that has characteristics of a muscle cell and is responsible for causing wound contraction?
Myofibroblast
The mostcommonly used bandage for temporary immobilization of fractures distal to the elbow or stifle?
Robert Jones Bandage, or a Modified Robert Jones Bandage
A type of slinf used to immobilize the front limb against the chest to prevent weight bearing?
Velpeau
Primary wound closure
Appositional
Placed to prevent excessive abduction of the legs, common in cattle and horses?
Hobbles