Burns Flashcards
What are the 3 zones of injury that occur with burns
Zone of Coagulation
- Point of maximal damage
- Irreversible tissue loss r/t coagulation of proteins
Zone of Stasis
- Surrounds zone of coagulation
- Decreased tissue perfusion
- Microthrombus formation
- Neutrophil adherence
- Fibrin deposition
- Potentially salvagable
Zone of Hyperaemia
- Outermost zone
- Increased tissue perfusion
- Local inflammatory response
- Usually recovers unless prolonged hypotension, Oedema or Infection
Systemic responses that occur in major burns
Cardiovascular
- Increased capillary permeability leading to leaking of fluids and proteins causing Oedema
- Peripheral and Splanchnic vasoconstriction
- Decreased contractility, Systemic hypovolaemia
Respiratory
- Bronchoconstriction
- ARDS
Metabolic
- Increased BMR (3 x resting)
- Catabolism if TPN not commenced early and aggressively
- Electrolyte shift -> Sodium moves into damaged cells, while potassium moves out = Hyperkalaemia
- –> Increases resting membrane potential = skeletal and cardiac muscle contraction
Immune
- Downregulation of immune system
How are burns classified
Superficial epidermal Superficial partial thickness Mid-dermal partial thickness Deep dermal Full thickness
What are the types of burns
Thermal - scald - flame contact Electrical Chemical Radiation
What is the Parkland Formula
The formula used to calculate fluid replacement requirements in burn victims
4mL x weight in kG x %TBSA = Daily requirements
Add 2,000mL maintainence fluid
50% given in first 8 hours
25% given in next 8 hours
25% given in last 8 hours
Describe and compare superficial partial thickness burn to a deep partial thickness burn
SPTB involves the epidermal and superficial dermal layers, whereas DPTB extend deep into the dermal layer
SPTB appear red or mottles and the underlying skin is blanchable, DPTB appear pink to pale ivory and the underlying tissue does not blanch.
SPTB are very painful compared to DPTB due to nerve fibres still being intact in SPTB.
SPTB healt <14 days
DPTB take >3 weeks to heal with surgical closure
What 2 factors determine the extent of systemic effects of a burn
TBSA % affected
Depth of the burn
ID 5 factors that need to be considered when determining the depth of the burn
How the injury occured Causative agent Temperature of agent Duration of contact Age-related skin thickness Anatomical location of burn First aid measures employed
Why do burn patients have a prolonged hyper-metabolic state
Results from an increased O2 demand/consumption
r/t increase and resetting of the thermoregulatory set point and is mediated by the stress hormones adrenaline, noradrenaline and cortisol
What is Silver Sulfadiazine
a topical cream containing silver nitrate with sulfonamide antibiotic
Possesses bacteriostatic qualities
Pt may experience pain, burning or itching upon application.
Hypersensitivity reaction possible
What is Nanocrystaline Silver (Acticoat)
A antimicrobial dressing
Has 3 layers:
absorbent inner core contained between outer layers of silvercoated polyethylene net, which is low adherent
The dressing is moistened and applied to the wound where the silver ions are released onto the wounds surface
Destroys gram +ve/-ve bacteria and helps reduce inflammation
Identify the mechanism of action, dose and side effects of LORAZEPAM
Facilitates binding of GABA
1mg - 4mg
CNS and respiratory depression
Identify the mechanism of action, dose and side effects of MORPHINE
PO 5mg - 20mg
IM/SC/IV 0.5mg - 10mg
Original opioid agonist of which newer ones are compared to for efficacy
Identify the mechanism of action, dose and side effects of FENTANYL
Opioid agonist SC/IV 50 - 100 micrograms PAtch 12 - 100 micrograms Lozenge 200 - 1600 micrograms CNS and respiratory depressions Used in Acute, Break through and Chronic pain. Epidural anaesthesia Pre-hospital adjunct to anaesthesia and sedation
Identify the mechanism of action, dose and side effects of MIDAZOLAM
GABA - mediated CNS inhibitory pathway anxiolytic, sedative - hypnotic, muscle relaxant
SLOW IVI 1 - 2.5mg over =/> 2 minutes
additional 1mg =/> 2 minute intervals (MAX 5mg)
CNS depressant, Hypovolaemia, Vasoconstriction, Hypothermia
