CSI 19- Acutely unwell Adult Flashcards
what is characterised as a major burn? and what percentage is more likely to affect wider systemic part of the body?
major = 15%
systemic = 25%
Epidemiololgy
How do most burns occur?
Most common admission cause is a scald
Major burns = flame
Mostly accidental
What risk factors would increase your chance of having a major burn?
Low economic status
grils having domestic roles
old age ; frail
overcrowding
psychiatric illness
what is used as a risk prediction to check mortality of burn?
give name and details esp point of futility
Revised Baux score
takes into account age, TBSA and presence of inhalation injury.
Point of futility: where mortality approaches 100%, it was 100 before but now 160.
what other risk prediction tools are used in burns
- Belgian Outcome in Burn Injury
- abbreviated Burn Severity Index
- Clinical frailty scores
Outline the layers of the skina nd it’s function
Epidermis needs dermis to regenerate every 2-3 wks
outline the different classification of burns in terms of severity
Epidermal (1st degree)
Superficial partial-thickness
Deep partial-thickness
3rd degree (full thickness)]
fourth degree ( to bone)
what factors affect severity of burns?
- wet scalds (more heat than dry scald )
- age
- if first aid was given early
outline the pertinent differences between the classification of burns.
superficial: can heal without scarring in 1-2 weeks.
deep: lost dermal vascular plexus and hence managed by excision and grafting.
can also lead to compartment syndrome and rhabdomyolsysis
Outline the local effects of major burns
Local events are divided into 3 zones.
Zone of coagulation: dead tissue
Next zone of stasis: hypoperfusion secondary to vasoconstriction and hence vulnerable to ischaemia and necrosis.
Zone of hyperaemia and vasodialtion
outline the systemic effects of a burn
Acute phase up to 48hr after injury due to:
- peripheral vasodilation
- hypovolemia
- myocardial depression
leads to shock and hypermetabolic phase that last til 1 year.
Hence early wound excision is better to decrease necrotic load
Initial management of burns
Describe how you will perform first aid
Cooled immediately under running cool water for atleast 20 min.
Use SAFE approach (shout, assess, flee danger and evaluate)
Although burn area should be cooled, the rest of the pt should be warmed
Acid burns irrigated for 45 min and alkali fro 1 hr
Use ABCD approach (ATLS)
How can the airway and breathing be compromised in burns
inhalation injury
Ventilation
what are the indications for intubation in burns pt
Reduced GCS due to:
- systemic toxicity from inhalation injury
- head trauma from escape
Actual or impending airway obstruction due to deep neck or intraoral burns and oedema
Resp distress
Safe Transfer to burns center
How can ventilation be impaired in burns and give treatment
dead tissue non-complaint and cant ventilate and reduce pre-load
- need escharotomies before transfer
Hypoxameia can occur due to CO poisoning
- need 100% O2 until carboxyhaem is less than 3%
Hydrogen cyanide poisoning should be considered esp with inhalation injury
- treat with hydroxycobalamin
Explain how inhalation injury can occur and symptoms
Hot gas particles burn the upper airway directly
particulate matter enter lower airway
CO and HCN can cause systemic toxicity
symptoms:
- facial burns
- horasness of voice and stridor
how do you manage inhalation injury?
Intubate but prepare for difficult airway due to ulceration and oedema
Mitigate by:
- Giving Suxamethonium up to 48h post-burn
- Video laryngoscope be used
- uncut tracheal tube to allow for further soft tissue swelling
Explain how you would manage the circulatory problem associated with burns
Assess for hemodynamic instability.
use 2 large bore (14G) cannula.
Use parkland formula (3mls) for resus
- ½ in first 8 hr and 1/1 in remaining 16
- subtract any fluid given already
- use warm isotonic crystalloid
for maintenance : use parkland formula
what causes low GCS in burns? esp at presentation
CO and HCN
trauma
medical comorbidities
Outline the principles in estimating exposure in burns
All clothes be removed,
reduce exposure due to hypothermia
erythema alone is not sufficient
Do not overestimate as it can affect parkland
Use rule of nines or even better the Mersey burns app
what is involved in the secondary survey in burns
Corneal damage: assess using flouresciene
CK needed for rhabdo esp in electrical burns
Tetanus toxoid treatment
Pain relief using IV opioids
NG tube for gastric decompression
Outline the procedure for escharotomies?
escharotomies: surgical excion through on compliant full thickness BURN
Should be performed as soon as they require ventilation
Incisional incision from unburned skin to unburned skin
Anaesthesia and diathermy used.
Add Abx
how are echarotomies different from fasciotomies
fasciotomies are deeper as it passes through the muscle fascial layer
Indicated in compartment syndromes commonly caused by high V electrical burns
Algorithm for fluid therapy:
Outline it if there’s no hypovolemia and no need for fluid resus
what are the indications that a pt may need fluid resus
Assess volume status taking into account clinical examination, trends and context.
Indicators that a patient may need fluid resuscitation include:
- systolic BP <100mmHg;
- heart rate >90bpm;
- capillary refill >2s or peripheries cold to touch;
- respiratory rate >20 breaths per min;
- NEWS ≥5;
- 45o passive leg raising suggests fluid responsiveness
outline algorithm if they DO need fluid resus
if pt doesn’t have complex fluid or electrolyte replacement of distribution losses, outline the algorithm for routine maintenance
Give maintenance IV fluids Normal daily fluid and electrolyte requirements:
- 25–30 ml/kg/d water
- 1 mmol/kg/day sodium, potassium*, chloride
- 50–100 g/day glucose (e.g. glucose 5% contains 5 g/100ml).
Reassess and NGT is preferable when maintenance needs are more than 3 days
Outline algorithm 4 when there’s abnormal losses and distribution
Algorithm 4
How do you check for existing fluid or electrolyte deficits or excess
Algorithm 4
How do you check if there’s ongoing losses and hence estimate the amount?
Check for:
- vomiting and NG tube loss
- biliary drainage loss
- high/low volume ileal stoma loss
- diarrhoea/excess colostomy loss
- ongoing blood loss, e.g. melaena
- sweating/fever/dehydration
- pancreatic/jejunal fistula/stoma loss urinary loss, e.g. post AKI polyuria.
Algorithm 4
How do you check if there’s Redistribution losses and complex issues
Check for:
- gross oedema
- severe sepsis
- hypernatraemia/ hyponatraemia
- renal, liver and/or cardiac impairment.
- post-operative fluid retention and redistribution
- malnourished and refeeding issues
Seek expert help if necessary and estimate requirements.
how much fluid is reabsorbed by the blind-ended lymphatic system per day
3L
outline how burns can lead to distributive shock, cardiogenic and hypovolameic shock
Distributive: most common type
Hypovolaemic: evaporation
Cardiogenic: cardiac stress due to less venous return esp in full-thickness burn. and TNF-a reduces cardiac contractility.
what is the difference between hypovolaemic and distributive shock?
Hypovoalemic: fluid/plasma is ACTUALLY LOST FROM body
Distributive: fluid is redistributed elsewhere in the body and leads to intravascular depletion.
explain how obstructive shock can occur and five examples of causes
something within the circulation is blocking flow to tissues and lead to flow.
e.g:
- acute pericardial tamponade,
- tension pneumothorax,
- pulmonary or systemic outflow obstruction
Breakdown the different types of causes: circle picture
after inital resus of burns (incl ABCDE), what must you consider?
- Admission to specialist : depends on TBSA (10-20%) and depth of burn (full thickness), face burns or circumferential burns
- Ongoing fluid resus
- Supportive care in ICU esp with nutritional support or inhalation injury
- Tetanus
- Surgery (full partial thickness) or compartment syndrome which will require fasciotomy or escarotomies
- VTE prophylaxis
- Pain and anxiety
outline the rule of nines
what are the similarities and differences beteen partial thickness and intermediate thickness burns
Intermediate need surgery and will scar, partial will not
Both blister and weep
Increased risk of infection the deeper it is
outline the features of 3rd and 4th degree burns
Dry and insensate
High risk of infection and will need grafting
Lead to contracture
4th: to bone and complete loss of burnt part
Outline how these fluid types will redistribute in the body fluid compartments in a normal healthy adult and explain why:
- 1L saline
- 1L dextrose
- 1l Hartmann’s / Ringer’s Lactae
1L 5% dextrose:
- Need fluid in intravascular space
- Assumption is that glucose transporters are passive
- It will split 2/3 intracellular and 1/3 extracellular
- Not good for burns as it does not bulk up the extravascular space
1L saline 0.9%
- Cells cannot take up Na as the Na+/K pump expels ALL Na back out
- Fluid builds up in interstitial space and hence in blood
- Good for burns and preserves volume as it is split 75-25
- Problem is the more you administer, the more you dilute bicarb in the blood (lose buffering capacity) and hence can lead to hypercholreamic acidosis
- Much cheaper to use and more widespread is used.
Ringer’s lactate/Hartmann’s
- It generates bicarb an prevents hyperchloreamic acidosis
- Concentration of Hartmann’s is lower than saline and hence will enter cells
Why is colloid not used widespread and explain it’s distribution
100% should enters plasma but not seen in practice.
Problems:
- could cause problems in widespread inflammation.
- It can cause allergy and anaphylaxis hence it is phased out.
outline the psych effects of burns
Facial burns cosmetics
Hand burns esp dominant- not good if you play music
PTSD symptoms:
- Hyperarousal
- Dissociation
- Avoidance
- Insomnia
- Hypoarousal
- Flashbacks
what are the features of the hypermetabolic state?
by a hyperdynamic circulatory response with esp with those with 40% TBSA:
- massive protein and lipid catabolism, total body protein loss
- muscle wasting,
- peripheral insulin resistance,
- increased energy expenditure,
- increased body temperature,
- increased infection risks, and
- stimulated synthesis of acute phase proteins located in the liver and intestinal mucosa.
it starts within 5 days and persist up to a year
describe and explain the 2 distinct patterns of metabolic regulation post injur
ebb phase:
- occur within 48 hr
- decreased CO, O2 consumption and met rate
- impaired Glucose tolerance and hyperG
Flow phase:
- gradual increase in metabolism within first 5 days
- insulin release is twice normal but glucose stays high due to resistance.
- hyperdynamic circulation and hypermet state.
Explain glucose metabolism in hypermetabolic state
Stress response: cortisol and catecholamines do their job
However hyperglycaemia FAILs to suppress hepatic glucose output and insulin effect is attenuated a lot
catecholamines affect GLUT-4 therefore affecting peripheral insulin resistance
Explain protein and lipid metabolism in a hypermetabolic state
iN BURNS , pts cannot metabolise fats and ketones
Hence loss of lean muscle is needed to provide energy due to inflammation (mediated by TNF-a)
may even contribute to insulin resistance
this can affect development in children
Outline the pharmacological interventions to slow the hypermetabolic state (even in kids) in acute and chronic
Analgesia: IV opioids and psychotherapy for anxiety
Oxandrolone: testosterone analog to reduce loss of lean muscle (even in kids)
Insulin acutely : IN SEVERELY burned pts with diabetes and target should be between 110-150.
GLP-1 agonist: those without diabetes
Metformnin
Growth hormone: kids alone and chronic and do not use infection or sepsis
Propanolol: stop catecholamines which lead to insulin resistance
Outline the NON-Pharmacological interventions in hypermetabolic state
Early wound closure using autologous grafts
For those with moderate to severe burns - increase ambient temp to 33C to reduce resting energy expenditure
A balanced physical therapy is needed to restore metabolic variables and improve outcomes
High caloric (high carb/lowfat) nutritional support via enteral feeding
- burn pts cant store fat as VLDL or even metabolsie it
what is the formula to calculate energy expenditure
Currie formula
what are the different types of grafts?
Xenograft: another species and only used on a temporary basis
Autografts: pts own uninjured skin and the mainstay.
Isograft: from identical twin
Allograft: used with TBSA over 40%. derived from cadavers. Can lead to rejection
