Burns, Hypothermia, Frostbite Flashcards
(28 cards)
Frostbite
- Characterized by a cold-exposed area that is cyanotic, hard, waxy, and tender, with surrounding edema
- Dx is clinical. CT, angiography, MRI/MRA, bone scan to determine extent of nonviable tissue.
- Tx is with trunk warming, circulating warm water immersion. If tissue does not recover, it may need to be amputated. Analgesia and tetanus prophylaxis. Manage suspected infections aggressively.
Hypothermia
- Defined as core body temperature <35 C [95 F]
- Severe is < 28°C [82°F]
- Tx:
- Mild cases: Passive rewarming measures (e.g., warm clothing, blankets)
- Severe cases: Extracorporeal blood rewarming. Carries risks of stroke, hemorrhage.
Exam for suspected hypothermia should begin with. . .
. . . core temperature measurement and then ECG
This is often best done by rectal temperature
The most common cause of death in the case of hypothermia is. . .
. . . arrhythmia
Etiologies of hypothermia that don’t involve exposure
- Increased heat loss: Erythroderma (burns, psoriasis, pemphigus, etc), surgery, sepsis
- Decreased heat production: Endocrinopathy (hypothyroid, hypopituitarism, hypoadrenalism), severe malnutrition, neuromuscular insufficiency
- Impaired thermoregulation: Damage to the preoptic nucleus of the hypothalamus. Many mechanisms by which this can happen (trauma, strokes, toxic/metabolic, Parkinson’s, Wernicke’s, MS)
Stages of hypothermia and associated signs + symptoms
In hypothermia, what do you warm first: trunk or extremities?
TRUNK
The extremities will remain hypoperfused until the trunk is warm
What’s so bad about arrhythmias in a hypothermic patient?
They don’t respond to defibrillation
When a hypothermic patient has an arrhythmia, you have to continue CPR until their trunk is warm again (30–32°C / 86–90°F), THEN defibrillate.
Passive and active rewarming
- Passive: remove wet clothing, cover with blankets, warm room (preferably 28°C (82°F))
- Active: immerse affected extremity in a warm (preferably 37–39°C) circulating water bath
Differences between the Parkland Formula and the Modified Brooke Formula
Modified Brooke uses crystalloid during the first 24 hours and colloid (5% albumin in LR) solution during the second 24 hours. It also uses a range of 2-4 mL as the constant.
During the second 24 hours, fluids are given at 0.3-0.5 mL x % BSA x kg.
Both titrate to a urine output of >0.5 mL/kg/hr using the estimates as a base.
Silver sulfadiazine
- Most commonly applied topical agent for superficial burns
- Lacks the ability to penetrate eschars
- Not useful in infected burn wounds
Sulfamylon
- Topical agent used for full-thickness, infected burns
- Can penetrate eschars
- Painful w/ application
- May cause metabolic acidosis due to inhibition of carbonic anhydrase
Silver nitrate
- Topical burn wound agent
- Has limited eschar penetrance
- Turns tissue a black color
- Leads to leeching of salt from tissue, which may produce hyponatremia/hypochloremia, particularly if widely applied in children
“Major” burn wound
Arbitrarily defined as injuries with > 20% BSA involvement
Requires inpatient management
Three phases of burn management
- Phase 1: Evaluate extent of wound, administer fluids, secure airway if necessary
- Phase 2: Initial wound excision and biologic wound coverage to prevent/minimize wound sepsis, systemic inflammation, and generalized sepsis
- Phase 3: Definitive wound closure/coverage and treatment of injuries to complex anatomic regions (hand, face, genitalia). Rehabilitation and reconstruction.
The first two things you want to consider when evaluating a burn patient
- Is there respiratory involvement of the burn?
- Does this patient have carbon monoxide poisoning?
All victims rescued from the scene of closed-space fires should have. . .
. . . their carboxyhemoglobin measured
The carboxyhemoglobin symptom scale
- >5%: Respiratory changes
- >30%: CNS dysfunction
- >60%: Coma, death
When is it okay to fluid resuscitate a burn patient orally?
When <15% BSA is involved in 2nd/3rd degree burns
Why do we prefer LR over NS for burn patients?
They are going to need large-volume resuscitation, and large volumes of NS can cause hypochloremic metabolic acidosis
Target urine output in burns: Adults, kids, infants
Adult: 0.5 mL/kg/hr
Kid: 0.5-1 mL/kg/hr
Infant: 1-2 mL/kg/hr
How to assess for abdominal compartment syndrome
Measure the bladder pressure!
Bladder pressures > 20 mmHg plus evidence of at least one dysfunctional abdominal organ are indicative of abdominal compartment syndrome
This suggests the need for fasciotomy or escharotomy in a burn patient
Biologic wound dressing
- Preferred form of wound dressing for burns
- Should be applied as early as feasible following wound excision to second and third degree burn sites
- Optimal would be autologous skin graft
- Otherwise, porcine or bovine xenografts, cadaver skin, and acellular dermal matrix are possible tools.
- Improve time to epithelialization, reduce hypertrophic scarring, fluid and heat loss, and pain.
Neurologic burn complications
Transient delirium is quite common, usually due to anoxia or metabolic abnormalities
