ABC of Burns Flashcards
What are the 5 types of burns?
Scalds Thermal Electrical Chemical Radiation
Define scald
Wet heat burn
Define thermal burns
Dry heat burns, result from direct contact with flames/hot appliances
What does the severity of a chemical burn depend on?
Type of chemical Concentration of chemical Contact time Quantity Surface area Ease of absorption Systemic effects Temperature
What are radiation burns caused by?
Exposure to sunlight or sunbeds
What are the depths of electrical burns dependent on?
The energy transfer to the tissues (depends on voltage, contact time and factors lowering resistance to current, e.g. skin moisture)
Define a burn
A dynamic wound, that changes over time and is subject to the effect of secondary injury or external factors
What is Jackson’s burn model?
Describes the areas of tissue in a burn and how they are affected
What are the layers in Jackson’s burn model?
Area of coagulative necrosis
Zone of stasis
zone of hyperaemia
What occurs in the area of coagulative necrosis?
Direct transfer of heat to tissue and an inability to conduct heat away rapidly enough leads to immediate coagulation of cellular proteins leading to their death
What occurs in the zone of stasis?
Less damaged tissue in which inflammation occurs and vascularity is impaired leading to tissue ischaemia
Damaged but potentially viable (if adequate steps not taken, e.g. fluid resus, may become zone of necrosis)
What occurs in the zone of hyperaemia?
Caused by release of inflammatory mediators from damaged tissue
Characterised by reversible increase in blood flow and inflammation
Once inflammatory response resolves, region returns to normal
What is defined as a significant burn injury?
20-25% TBSA
What can occur in a significant burn injury?
Alterations in the function of almost all the organs
Leads to release of inflammatory mediators from damaged tissue and neural stimulation
What vascular changes do burns cause in the body?
Losses of fluid, e.g. weeping from partial thickness burns
Widespread changes - vasodilation + increased capillary permeability –> loss of protein + fluid –> hypoperfusion –> cell death (due to hypovolaemia shock)
Why is early correction of hypovolaemia essential in burns management?
To prevent hypovolaemic shock and cell death
How can the kidneys be affected by a significant burn?
AKI can result due to hypovolaemia, release of Hb from haemolysed cells and myoglobin from damaged muscle
What is meant by the body entering a hypermetabolic state after a significant burn?
Secretion of stress hormones - cortisol, glucagon, catecholamines and suppression of anabolic hormones (e.g. insulin, GH) to mobilise amino acids to begin repair of tissues
Leads to profound catabolic state and muscle breakdown
Why do burns patients become immunosuppressed?
Due to release of cortisol
What are the complications of burn wound infection?
Delayed healing
Increased scarring
Bacteraemia, sepsis
What are the most common pathogens of burn wounds?
Bacteria and fungi (often commensals)
When do burn injections most commonly occur?
After 48-72h after injury
What can the systemic inflammatory response post-burn cause in the lung?
ARDS
Which GI condition is common in burns and what drug is given prophylactically to prevent it?
Stress ulcers, PPIs
Also gastroparesis isn’t uncommon
What are some long term sequelae from having a large burn?
Changes in overall growth and development
Contractures etc.
How can long term sequelae of burns be prevented?
Correct posture, splinting, early physio
Mobilising
Surgical management of contractures etc.
What history should be taken from a burn patient?
Time of injury Circumstances First aid received Analgesia taken Date of last tetanus jab Relevant illnesses, e.g. DM Relevant drugs, e.g. steroids, warfarin Allergies to dressings, antibiotics etc.
What is the order you should follow when treating burns victims?
First aid
Primary survey
Secondary survey
What does first aid of burns involve?
Stopping the burning process (e.g. extinguishing flame, irrigation if chemical)
Hold region under water for 20m
Wrap clingfilm around wound to travel to hospital
What is the ideal temperature of water to run over a burn?
15C
Why is running cool water over a burn important?
Reduces inflammatory reaction so can stop procession of necrosis into zone of stasis
Effective analgesic
What should you be careful of when running cool water over a burn?
The patient becoming hypothermic
Why should you not use ice or iced water to cool a burn?
Extreme cold leads to vasoconstriction which may deepen tissue injury
What is involved in the primary assessment of a burn?
ABCDEF
A - airway + cspine control
B - breathing
C - circulation + haemorrhage control (direct pressure to bleeding wounds), pulse, cap refill, insert 2 large bore cannulas, catheterise patient
Also take bloods (UE, FBC, clotting, glucose, group and save/cross match and carboxyhaemoglobin), ABG
D - disability ,AVPU/GCS
E - exposure + environmental control (remove all clothing etc., keep warm, log roll patient onto back)
F - fluid resus
What does AVPU stand for?
A - patient is Awake
V - patient responds to Verbal stimulation
P - patient responds to Painful stimulation
U - patient Unresponsive
If you cannot insert two large bore cannulae into a burns patient what should you do?
Insert a central venous line or get intrasseous access
What formula should you use to calculate how much fluids to give burns patients in the first 24 after injury?
Parkland formula
What other investigations/immediate management may you consider in a burns patients?
X-Ray - chest, pelvis, lat c spine
Analgesia - IV morphine best
Tetanus immunisation
Antibiotics
What is involved in the secondary survey?
AMPLE A - allergies M - medications P - past illness L - last meal E - events/environment related to injury
Check MSK, neurological Ex, check head, face, abdomen chest etc.
What are the different categories of burn depth?
Superficial (1st degree)
Partial thickness/deep dermal (2nd degree)
Full thickness (3rd degree)
What area of skin do superficial burns affect?
Epidermis + superficial layer of the dermis (papillary dermis)
What is the appearance of a superficial burn?
Red and blistered
Normal capillary refill
Are superficial burns painful and why?
Yes - due to exposure of sensory nerve endings
How long do superficial burns take to heal?
14 days
How do superficial burns heal?
By epithelialisation
What kind of scar do superficial burns leave?
Don’t scar
Just leave a colour match defect
What area of skin do partial thickness burns affect?
Epidermis and reticular dermis
What do partial thickness burns appear like?
Areas of necrosis and blisters may be seen
Capillary refill time diminished/absent
Sensation to pinprick lost
Why is the capillary refill time prolonged in partial thickness burns?
The burn has destroyed the dermal vascular plexus
Why is sensation to pinprick lost in partial thickness burns?
Dermal nerve endings are destroyed by the burn
How should you manage a partial thickness burn?
Dressed with antibacterial dressing and referred to burn surgeon
How deep are full thickness burns?
Destroy epidermis and dermis and may even penetrate into underlying structures
What is the appearance of a full thickness burn?
Waxy, white or charred
Skin looks shiny
Loss of sensation
What is the coagulated dead skin of a full thickness burn called?
Eschar
Are full thickness burns painful? Why?
No - nerve endings are destroyed by the burn
Why is it important to estimate the area covered by the burn?
Mortality is related to %TBSA and age of patient
What is the most accurate way to calculate %TBSA?
Lund-Browder chart (remember not to include areas of erythema)
What may be used to calculate %TBSA in an acute setting?
Wallace’s rule of 9s (head, each arm 9%, chest, back, each leg 18%, perineum and hands 1%)
Paediatric rule of 9s
What is Parkland formula?
Volume of fluid = 4ml x %TBSA (up to 50%) x wt (kg)
Give first half in first 8h and last half in next 16h from injury
When are resus fluids recommended for a burn?
%TBSA >10% in kids, >15% in adults
What should you do if giving a patient fluids for a burn?
Catheterise to ensure adequacy of fluid resus
How do you calculate fluid resus for burns in kids?
Parkland formula expect 2ml instead of 4ml + paediatric maintenance fluids
How do you calculate paediatric maintenance fluids?
Normal saline (+/-5% dextrose to prevent hypoglycaemia):
100ml/kg up to 10kg +
50ml/kg from 10-20kg +
20ml/kg for each kg over 20kg
What ways can you monitor fluid resus?
Catheter Central venous line BP HR ABG
What urine output should you aim for in adults when giving resus fluids?
0.5ml/kg/hr (if over 50kg)
What urine output should you aim for in kids (<50kg) when giving resus fluids?
1ml/kg/hr
What things on ABG may indicate inadequate tissue perfusion?
pH <7.35
Raised lactate
By how much does an inhalation injury increase the mortality rate?
40%
What is an inhalation injury?
Damage caused to the lungs by inhalation of various products of combustion, may also result in systemic absorption of harmful products
What are the symptoms of an inhalation injury?
SoB, wheezing, brassy cough, hoarse voice
What are the signs of an inhalation injury?
Soot in oral/respiratory secretions Burns around face/mouth Altered consciousness Increased RR/effort of ventilation Stridor
What are the three types of inhalation injury?
Supraglottic (above larynx) - thermal injury to airways due to inhalation of hot gas –> release of inflammatory mediators –> oedema and ventilator obstruction
Subglottic (below larynx) - chemical injury to alveoli
Systemic (absorption into systemic circulation)
What are the two most important substances implicated in inhalation injuries?
CO
Cyanide
How can CO cause inhalation injuries?
It diffuses rapidly into the bloodstream and combines with Hb with an affinity of 240x of O2 to produce carboxyhaemoglobin
Burning of what materials produces cyanide?
Certain plastics
What features result from cyanide poisoning?
Loss of consciousness
Neurotoxicity
Convulsions
What is the management of inhalation injuries?
Humidified oxygen 15L/min via non re-breathing mask
Monitor sats continually
Involve senior and anaesthetist
What is the burns referral criteria for referral to a burns specialist centre?
%TBSA - 2% in kids, 3% in adults
Site - consider if face, hands, feet, perineum, genitals
Mechanism - NAI, consider if electrical/friction/cold burn
Burn depth - full thickness, circumferential
What immediate surgery may be used in burn victims?
Escharotomy Fasciotomy Debridement of devitalised tissues Necrectomy of burn area Dermo-epidermal graft Local flap
What is an escharotomy and why might it be necessary?
Dry eschar can act like a tourniquet and may constrict a patients neck or chest or circulation in fingers
As oedematous tissue swells, the eschar around it is rigid and cannot expand
Escharotomy may be necessary to aid respiration/prevent limb ischaemia
What surgery might be done a little later on?
Excision on non-viable skin
Skin grafting
What late surgeon may be performed on burn victims?
Release of contractures
Post-burn reconstruction
What is tangential excision?
Shaving away layers of skin until you reach viable/bleeding tissue
What is the major issue with tangential excision?
Blood loss
While burn patients are undergoing surgery, what other things should you try and do?
Monitor core temp to prevent hypothermia
Avoid hypo/hypervolaemia
Minimise blood loss
What causes electrical burns?
Generation of heat caused by the resistance of tissues to current of flow
How are electrical burns categorised?
Low voltage - below 1000V
High voltage - above 1000V
Lightening injuries - very high voltage
The amount of heat generated by a tissue during an electrical burn is directly proportional to what?
Amount of current, tissue resistance and duration of contact
Amount of tissue damage also depends on surface area contact and pathway through the body
List the tissues in the body in order of least to most resistant to electrical energy
Nerve Vessels Muscle Skin Tendon Fat Bone
Tissues with the lowest resistance sustain the most damage
What additional things are involved in the management of an electrical burn?
Turn off power supply etc.
Electrical discharge may affect medulla and so risk of cardiac arrest - CPR is essential initially and ECG should be obtained and monitored for at least 24h followed injury
How are the chemical agents causing burns roughly categorised?
Acids
Alkalis
What kind of injury does an acid cause?
Coagulative necrosis
What kind of injury does an alkali cause?
Liquefactive necrosis
Why should you not use a neutralising agent when managing chemical burns?
Exothermic reaction when applied will produce heat and lead to further damage
irrigation is mainstay
What are common acids causing chemical burns?
Sulphuric, nitric, hydrochloric, hydrofluoric
What are common alkalis causing chemical burns?
Sodium, potassium hydroxide, wet cement
If a burns patient is still really dehydrated after resus fluids what can you do?
Fluid challenge (250-500ml fluid over 15-30m)
What source has the most up to date information on burns?
COBIS - care of burns in Scotland
What is the modified parkland formula (as used to calculate resus fluids in paediatric burn vitcims)?
total vol. Hartmans = %TBSA x wt (kg) x 2
After 8h, next 16h calculated as:
hourly rate of albumin 4.5% = %TBSA x wt (kg) x 0.1ml
What is the most common cause of burns in adults?
Thermal
What are the most common cause of burns in kids?
Scald
What do you see on ABG with CO poisoning?
Metabolic acidosis
What fluid is mostly used in burns fluid resus?
Human albumin
What is the Muir and Barclay formula?
%TBSA x body wt x 2
Gives fluid loss due to burn, must give additional fluid to cover normal daily losses
In a child who has a major burn, after giving them fluids and inserting a catheter what else should you do?
Talk to parents Give IV analgesia Establish tetanus immunisation status Send off baseline bloods Insert a NG tube Continue O2 therapy
What bloods should you send off for a major burn?
Haematocrit - if high, needs more fluid
Group and save 0 in case need a transfusion
UE - check renal function okay
Will partial thickness burns heal on their own?
Yes
What things will reduce the chance of a skin graft taking?
Infection, haematoma, shearing forces on the graft
Why should burned areas be covered whilst outside for up to 2 years post-burn?
Burn scars are very sensitive to sunshine while they mature
What are some common post-sequelae problems in kids after they have a major burn?
Hypertrophic scarring Sensitivity to sunburn Contractures Further wound breakdown Further burning School problems Nightmares
What is hypertrophic scarring?
Thickened, red, itchy scars
What things might you like to elicit in the history about the circumstances of his injury?
Open vs closed fire place
Duration of exposure to smoke before being rescued
Jumping/falling while escaping from fire
Collapse of furniture or building structures on the victim
Explosions/blasts
Electrical injuries
Protective equipment
How does cyanide cause poisoning?
Interferes with mitochondrial respiration
What is involved in the management of suspected inhalation injury?
CXR Analgesia Bronchoscopy Humidified O2 via non-rebreath mask 15L/min Monitor sats continuously Large IV bore access Alert anaesthetist Order CO level
What is the standard treatment of CO poisoning?
100% O2 via tight fitting mask
What is the most effective treatment of CO poisoning?
Hyperbaric oxygen therapy in a hyperbaric chamber
If a patient comes in with a burn and is not immunised against tetanus what should you give them?
3 dose course of absorbed vaccine + human tetanus immunoglobulin
