Lacerations and wound management

Where will skin will be thicker?

Mane and tail

What is going to prolong healing wounds of extremities?

Reduced vasculature

Increased infection/inflammation

Reduced regional temp

What is important to know about equine cleavage lines?

They run parallel to collagen fibers

incisions should be made parallel to them to heal best

Where are distal limbs wound seen?

Below Carpus and tarsus

What are things to worry about distal limb wounds?

Tension - difficult to close

Close to ground - infection

Synovial structures - worry about joint infection

Most wounds will not heal right due to what?

Improper assessment

What is debridement used for?

Reducation of bacterial load and necrotic tissue

What tool is best to use for sharp debridement?

Scalpel - least traumatic but be conservative

What are mechanical methods of Debridement?

Woven gauze - gentle pressure

Lavage

Wet to wet

Wet to dry

How should we lavage a wound?

Non-cytotoxic fluid, w/ appropriate pressure to wash away debris and not push it in (19g needle 35ml syringe)

What is a wet to wet dressing?

Wet wound wet bandage will peal necrotic tissue off and leave healthy tissue - needs to stay wet!!!

What is wet to dry dressings?

Dressing on wound is wet and rest of bandage will be dry and pull the moisture from wound away

What is chemical debridement?

A non-selective debridement only meant for very contaminated wounds

What do you use in chem debridement?

H2O2

Hypertonic saline

What is biological debridement?

Maggots - digest only necrotic tissue and bacteria - selective and antimicrobial

What is autolytic debridement?

Least traumatic - leaves would fluid in contact w/ wound bed - make sure stays moist

What is contamination of a wound?

Bacteria w/out active multiplication or trauma

What is colonization of a wound?

Bacteria attached to tissue multiplying but no trauma

What is infection of a wound?

Bacteria multiplying and invading healthy tissue overwhelming immune response

What is used most commonly when trying to see bacteria in wounds?

Qualitative assessment - types of bacteria and sensitivity testing

What do we use antiseptics on?

Cleaning the healthy normal skin not wound bed itself - doesn't penetrate necrotic tissue well

When do we use a triple antibiotic ointment?

Loss of blood supply to wound bed

What wound classifications are best candidates for primary or delayed primary closure?

Clean/ clean contaminated in early stages of healing

What is primary closure?

Wound immediately and completely closed w/ aseptic technique - best functional and cosmetic results - minimal tissue loss

What suture patterns are used to reduce tension?

Near-far-far-near

Interrupted vertical/ horizontal mattress +/- stents

What can failure to close dead space lead to?

Hematoma/seroma - bacterial growth

What are methods to close deadspace?

Suture

Meshing the skin

Passive/active drains

Pressure bandage

What is a delayed primary closure?

Wound initially left open for debridement and reduction of bacteria, then closed

What is second intention healing?

Relies on horse physiology and granulation tissue - used in wounds that cannot be closed due to contamination/severe tissue loss

What is the ideal wound dressing?

Keeps wound bed moist and surrounding skin dry - Don't let wound dry out

What are types of wound dressings?

Hypertonic saline - debridement for abscesses

Manuka honey - bactericidal & growth factor

Antimicrobial dressings

Hydrogels (provides moisture)

Calcium alginate (during granulating phase)

What is kerlix AMD?

A cationic dressing that suppresses micro bacterial penetration and growth - no resistance possible (destabilizes cytoplasmic membrane)

What does calcium alginate do?

Interacts w/ sodium in wound and makes exudate stimulating myofibroblasts and epithelial cells

What are best for diagnostic aids of head wounds?

CT/MRI (not always available)

Rads

U/S

You should never use ___ near the eyes?

Chlorohex - use Betadine instead

What kind of suture should be used on the eyelids?

Small diameter absorbable sutures in many layers - eyelid is very mobile

What structure will not heal very well on the head?

Ears - mobile and cartilage

What can happen to the paranasal sinuses in head wounds

Bone sequestration and fistulas

What should you look for if the mandible is involved in a head wound?

Salivary duct and incisor involvement

Nares will usually need to heal via ___ if > 7 days old?

Second intention

What are we worried about if we have a thorax injury?

Ribs and pneumothorax (listen for air getting sucked into wound during inspiration)

How do you tx a thorax inj?

Broad spectrum antibiotics if pleural penetration

Stent bandages

What should you do if you have a peritoneal penetration?

Bandage

Antibiotics

Refer - probs colic sx

What do we worry about w/ axillary lacerations?

SQ emphysema leading to pneumomediastinum - air filling sq/ pneumothorax

How do you tx axillary lacerations?

Pack wound w/ sling bandages

Limit horse movements - air must be reabsorbed

If there is a synovial structure involved what is treatment for a laceration?

Primary closure

Lavage

IV antibiotics

Local IV regional perfusion

What structures are we most worried about in a heel bulb laceration?

DDFT sheath/ coffin joint

If there is no synovial involvement how can we tx heel bulb laceration?

Delayed primary closure - very contaminate - need to debride

What should be suspected if a wound does not heal in anticipated time frame?

FB

Infection

Why would we do sx debridement on a chronic wound?

Turn it to acute - stimulates healing

What do we need to make sure of when we close a wound?

There is at least 1cm or more of skin around the edge to hold the sutures

What is a normal sinus tract/ draining tract?

Venous sinus

What is a fistula?

Abnormal passage or communication b/w two internal organs or from organ to skin

Sinus tracts are typically secondary to what?

Trauma/ FB

What is an example of a trauma induced sinus tract?

Distal limb kick from other horse leads to sequestrum of bone - body tries to push out

If there is a chronic sinus tract you should always suspect __ and can dx w/?

FB

U/S or xray

Radiographs are great for finding what kind of FB?

Metalic FB (can also use + constrast sinography for radiolucent)

Sinus tracts will usually have a ____ membrane?

Dark purple

Sinus tracts in the head can be due to what?

Sinus infection

Dental issues

Sinus tracts in the ear can be due to what?

Dentigerous cyst (ear tooth)

What would we be concerned with if we saw draining tracts in the withers (Fistulos withers) and pole (Pole evil) regions?

Brucellosis - titer - zoonotic

What horses tend to have thicker skin?

older geldings

Skin is thicker at what surface of legs?

extensor (front of legs)

What bacterial count constitutes an active infection?

10⁵ or 10⁶ per gram of tissue

What differentiates acute vs chronic wounds?

chronic have delayed expression of growth factors (proteolytic activity)