Treatment of Large Animal Wounds Flashcards
Wound healing has 3 overlapping stages…. what are they?
Inflammatory phase
Proliferative phase
Remodeling phase
What occurs during the inflammatory phase of healing?
Vasoconstriction for hemostasis
Vasodilation
Formation of provisional wound matrix
Cellular response
how long does the inflammatory stage last for?
0-3 days
How long does the proliferative phase last for?
2-14 days, usually active by day 3
What is the main objective of the proliferative phase?
protection of the wound surface by formation of granulation tissue & new epithelium
What is the purpose of angiogenesis?
To restore oxygenation & supply nutrients to granulation tissue
What is important to remember about granulation tissue?
It does NOT have nervous innervation
When does the remodeling phase begin?
Around day 7+
What percentage of final wound strength is achieved in the first 3 weeks?
- 20%
How long can scar formation take?
up to 2 years
Which heals better, ponies or horses? Why?
ponies - due to the differences in local inflammatory response & functional capacity of leukocytes
What are the 4 ways of classifying a wound based on contamination?
- Clean
- Clean-contaminated
- contaminated
- dirty or infected
What is a clean wound?
- surgical incisions made under aseptic conditions
- primary closures
What is a clean-contaminated wound?
Surgical incisions made to involve the respiratory, GI, or urogenital tracts entered under controlled conditions
What are contaminated wounds?
open wounds
Traumatic wounds
Sx incisions w/ major breaks in asepsis
What are dirty or infected wounds?
Exudative
Traumatic wound w/ delayed txt
Obvious contamination
Devitalized tissue present
What are examples of open wounds classified by type?
incisions, erosions, lacerations, burns, abrasions, punctures
What are examples of closed wounds classified by type?
bruises, hematomas, contusions
When classifying a wound based on bacteria, what are the options?
clean, clean-contaminated, contaminated
Dirty or infected
When classifying a wound based on time, what are the options?
Class 1 - < 6 hrs w/ minimal contamination
Class 2 - 6-12 hrs w/ significant contamination
Class 3 - >12 hrs w/ gross contamination
What sedative would you use when trying to assess wounds?
alpha-2 agonist & opioids
When do you take a swab for culture & sensitivity for wound management?
before you clean OR if its very contaminated, clean the outer aspect of the wound then lavage w/ sterile saline before swabbing deep
Determine the extent of wound by…
- probing/sterile gloved finger
- assess for damage to vital structures
- assess for foreign bodies, sequestrate, etc
What are some general considerations during wound management?
- Owner’s goals
- treat or refer?
- wound closure
- antibiotics, anti-inflammatories, TAT, or toxoid
- what type of dressing or bandage?
- box rest?
What type of local anesthetic can be used?
distant perineural nerve blocks
ring or splash blocks
What is the duration of action of lidocaine?
90-180 mins
What is the duration of action of mepivacaine?
120-180 mins
What is the duration of action of bupivicaine?
180-500 mins
What are the aims of debridement?
- reduce bacterial load & remove necrotic tissue
- more rapid & cosmetic healing
- minimise trauma to the wound bed
What are the main types of debridement?
sharp, mechanical, chemical, biological, and autolytic
What are the most common types of debridement in equines?
sharp and autolytic
What are some benefits to sharp debridement?
- one of the least traumatic
- cost effective
- allows assessment of tissue viability
- minimal equipment required
What are the 3 main forms of mechanical debridement?
woven gauze
Lavage
Versajet
When doing mechanical debridement with lavage, what is the appropriate pressure & volume?
10-15 psi by using a 35 ml syringe & 19 g needle with non-cytotoxic solution like sterile saline
What does versajet do?
uses water to debride mechanically
What are the types of autolytic debridement?
- hydrogels
- manuka honey
- chemical debridement
What are the three types of wound closure?
primary closure
delayed primary closure
second-intention healing
What are some considerations that have to be made when closing wounds?
- vascularity & tissue health
- debridement
- management of dead space/debridement
- facilities available
- box rest or not
- bandaging
What are some indications for mechanical debridement?
- surgical incisions
- minimal tissue loss
- minimal bacterial contamination
- minimal tension on wound edges
- exposed vital structures
What are examples of appositional suture patterns?
simple interrupted
cruciate
interrupted vertical mattress
What are examples of tension-relieving or everting suture patterns?
interrupted horizontal mattress
near-far-far-near
far-near-near-far
walking suture
What is the aim of drains?
to channel unwanted fluids & air from tissues or body cavities
What are some reasons to use a drain?
- eliminate dead space
- allow drainage of fluid/gas from the wound cavity
- prevent anticipated build-up of fluid
what makes an ideal drain?
inert, soft, non-reactive, radiopaque
what are some complications with drains?
foreign body response
ascending infection
delayed healing
What are some examples of passive drains?
gauze, penrose, sheet, tube
What are some active drains that can be used (closed-suction systems)?
infected joints
under full thickness skin grafts
large deep wounds
evacuating pleural space
When should a primary wound closure being used?
whenever possible
Why is primary wound closure ideal?
- reduced healing time
- improved cosmesis
- less aftercare & subsequently expense
- earlier return to function
What are some indications for delayed primary closure?
- initial treatment to allow debridement & reduce contamination
- mild/moderate bacterial contamination
- minimal tissue loss
- minimal tissue tension
When is second intention healing used?
- when neither primary or delayed primary closure is possible
What are some indications for second intention healing?
- primary/delayed primary closure not possible
- unmanageable contamination
- established infection
- excessive tissue loss
Granulation tissue is…
- very vascular
- devoid of nervous tissue
What are some indications of skin grafting?
- defects that exceed the ability of epithelialization or conventional closing techniques
- where cosmesis is important in large, slow-healing wounds
- where rapid healing is required
What are some common topical treatments?
- fucidic acid ‘Isaderm’
- Silver sulphadiazine ‘Flamazine’
- Manuka Honey
- Vulketan Gel
- Aloe Vera
- Corticosteroids
What is normal synovial fluid?
- translucent, pale yellow
- viscous
- TP = <10-20 g/L
- WBCs = 0.2 x 10^9 g/L
What is abnormal synovial fluid?
- increased volume
- lowered viscosity
- abnormal appearance
Cloudy, turbid, amber synovial fluid is a sure sign of…
septic arthritis
Haemorrhagic synovial fluid is a sure sign of…
traumatic arthritis
When looking at synovial fluid, what are sure signs of definitive sepsis?
WBC >100 x 10^9 g/L
TP >40 g/L
Neutrophils >90%
synovial contamination is an…
emergency
if there is exposed bone, what should you do on Day 1
Take radiographs
What is special about exuberant granulation tissue (EGT)?
it has no nerves but is increased blood supply
- unique to horses
What is bandaging used for?
- protection
- pressure
- support/immobilisation
- absorption
- optimal healing environment
Contact/primary layer of bandaging is a … layer and is either… or …
Sterile layer
adherent or nonadherent
What is the second layer of bandaging?
padding or conforming bandage
What is the outer layer of bandaging?
cohesive bandage for compression and support
What is adhesive tape for in bandaging?
to prevent slipping and debris tracking in or can be applied over length of bandage for extra compression & support
Splinting of limb fractures depends on…
location and have been divided into 4 levels for fore & hindlimbs
An effective splint must…
provide rigid support to neutralize the distracting forces acting at the fracture site
An inappropriate splint can make…
a fracture worse
Splints should extend one joint …
above and below a fracture splint
