50. Wound Management Principles Flashcards
What are risks for wound infection to consider
- location
- mechanism
- Host factors
- wound care
Risk of infection clean vs dirty wound
less than 1%
dirty wound >20%
Outermost layer of skin
epidermis
Most important parts of the epidermis?
stratum corneum - outermost cell layer (cosmetic)
stratum germinativum (basal layer) - new cells originate
What layer of skin is right below the epidermis?
dermis
What is the dermis
thick CT layer, primarily responsible for ultimate wound healing
Removing debris and devitalized tissue from the __ is key for optimal healing
dermis
What lies below the dermis and encloses subcutaneous fat?
superficial fascia
What is below the fat?
deep fascia - strong, off white sheath covers and protects muscle
Normal wound healing - sequence of biologic events (5)
- coagulation
- inflamm
- collagen metabolism
- wound contraction
- eipithelialization
After tissue integrity is altered, process of coagulation starts - how does this work? How does inflamm process work?
pl release factor to enhance response
cap permeab incr to allow WBC migration into wound
Neutrophils and monocytes scavenge to rid debris and bacteria
stimulation of fibroblast replication, trigger neovasc
Collagen stage of wound healing - what occurs?
synthesis, deposition then cross linking
synthesis and deposition by fibroblasts 48h post injury
immature collagen is highly disorg and gel like then fibrils interlink
Entire process of collagen interlinking is based on …
tissue lactate and ascorbic acid
tissue arterial co2 partial presssure
What 4 things are important for hydroxylated collagen?
vit c
prolyl
lysyl hydroxylase
o2
Under normal conditions when does collagen synthesis peak?
d7 with coinciding of rapid incr in tensile strength
The healing wound has greatest mass at _ weeks but remodels itseldf during next - months
3
6-12
Contraction phase of wound healing - what is this?
movement towards centre of defect
retraction of edge at first
then next 3-4 days as edges move to centre, wound size shrinks
Epithelialization - epithelial cells migrate across wound - what can impede this process?
eschar and edbris
What medical conditions may signficantly effct wound care decisions?
sign PVD
immunocompromised
high riksk of retained FB
Structural defects like damaged/prosthetic heart valves
RF for wound morbidity:
prolonged time since injury
crush mechanism
long >5cm and deep
patient age
high velocity missiles
location on LE
contamination with saliva, feces soil or other foreign material
__ hours after acute trauma, bacteria can proliferate to a level that may result in infection
3
For sutured wounds, __ has the strongest association with infection
location
Face and scalp have a infection risk rate after lac repair of 4% - what is this compared to leg/thigh or torso and other extremities
low
> 20%
10%
Rosen’s Box 50.1: Risk factors for wound infection (8)
- location - leg and thigh > arms >feet > chest > back > face > scalp
- contamin with devitalized tissue, fb, saliva or stool
- blunt/crush injury
- presence of subcu suture
- type of repair : suture > staple > tape
- anes with epi
- high velocity missile injury
- DB
Although uncomfortable, how high can a blood pressure cuff be held up in order to get a good PE view?
2 hours
Will radiography detect all foreign material?
no
What is the best imaging test for ID foreign material (but expensive so not really done)
ct
What is particularly helpful anesthesia for appropriate exam of a wound?
nerve block
Lidocaine onset of action following direct infiltration can take ?
seconds
Lidocaine length of action when direct infiltration?
20-60 mins
Lidocaine as a regional nerve block - onset of action? duration?
4-6 min
duration: 75 min
A 1% lido solution is ?mg/ml
10
Safe non epi dose of lido mg/kg?
3-5
If epi is added to lido why does this increase the safe dose?
vasoconstriction prolongs the effect
What is a safe dose of lido with epi?
5-7mg/kg
When should lido with epi be avoided?
high risk of infection wounds
tissue viability concern
Digital artery vasospasm can occur if local injection of epi given - how to successfully reverse?
0.5-2mg local injection of subcut phentolamine or application of topical NG
How does bupivicaine’s action of onset compare to lidocaine?
slower onset
lasts 4-8x longer
What is the preferred local anesthetic for care of most wounds?
bupivicaine due to lasting longer
Safe dose of bupivicaine without epi per kg?
2.5
Safe dose of bupivicaine wit epi per kg?
3-3.5
How often can bupivicaine dosing be given?
Not going over ?mg in 24h
3hrs
400mg
___ will buffer lido and reduce pain at injection site
bicarb
What ratio of Na bicarb can be added to lidocaine to decrease the pain of injection without compromising injection anesthesia?
1:10
1 ml bicarb, 10 of lido
What ratio of Na bicarb can be added to bupivicaine to decrease the pain of injection without compromising injection anesthesia?
1:100
0.1ml bicarb, 10ml bupivicaine
When is toxicity of LET decreased?
<3ml
not on mucous membranes