Cold Injuries Flashcards
(a) Signs and Symptoms
1) Patients may complain of pruritus and burning paresthesia.
2) Localized edema,
3) Erythema,
4) Cyanosis,
5) Plaques,
6) Nodules,
7) In rare cases, ulcerations, vesicles, and bullae.
The skin is pale, mottled, anesthetic, pulseless, and immobile, which initially does not change after rewarming
Chilblains
Treatment of chilblains
1) Management of chilblains is supportive.
2) The affected skin should be rewarmed gently.
3) To soothing lotions can relive itching
4) Nifedipine 30 to 60 mg PO QD x 7 days
a) Transient stinging and burning, followed by throbbing.
b) Partial skin freezing, erythema, mild edema, lack of blisters, and
occasional skin desquamation several days later.
c) Prognosis is excellent
First degree Frostbite
a) Recognized by large blisters containing clear fluid surrounded by edema and erythema, developing within 24 hours and extending
to or nearly to the tips of digits. The blisters may form an eschar, but this later sloughs off, revealing healthy granulation tissue.
There is no tissue loss.
b) Prognosis is good
Second degree Frostbite
a) The patient may complain that the involved extremity feels like a “block of wood,” followed later by burning, throbbing, and shooting
pains.
b) Hemorrhagic blisters form and are associated with skin necrosis and a
blue- gray discoloration of the skin.
c) Prognosis is often poor.
Third Degree Frostbite
a) The patient may complain of a deep, aching joint pain.
b) Extends to muscle and bone, involves complete tissue necrosis.
c) Vesicles often present late, if at all, and may be small, bloody blebs that do not extend to the digit tips.
d) Prognosis is extremely poor. Mummification occurs in 4 to 10 days.
Fourth Degree Frostbite
Important history for frostbite
a) What was the temperature and wind velocity?
b) How long was the extremity frozen, and if it was thawed, did any
refreezing occur?
c) Was there any self treatment, such as rubbing with snow or use of aloe
vera cream or ibuprofen?
d) Were recreational drugs, alcohol, or tobacco involved?
e) Are there any predisposing medical conditions?
Field management of frostbite
(1 Wet and constrictive clothing should be removed.
(2 The involved extremities should be elevated and wrapped.
(3 Carefully in dry sterile gauze, with affected fingers and toes separated.
(4 Further cold injury should be avoided.
(5 Do not rub frostbitten areas, this can cause further tissue damage.
(6 Avoid the use of stoves or fires to rewarm frostbitten tissue. Such tissue may be insensate and burn can result.
Clinical management of frostbite
a) Rapid rewarming is the core of frostbite therapy and should be initiated a soon as possible.
b) The injured extremity should be placed in gently circulating water at a temperature of 104°-107.6°F (40° to 42°C) for approximately 10 to 30 min, until the distal extremity is pliable and erythematous.
c) Clear blisters should be debrided or at least aspirated
d) Hemorrhagic blisters should not be debrided because this often results in tissue desiccation
e) Blister types should be treated with topical aloe vera cream every 6hrs.
f) Digits should be separated with cotton and wrapped with sterile, dry gauze.
g) Elevation of the involved extremities helps decrease edema and pain.
Hypothermia is defined as a core temperature below
95°F
Temperature stages for hypothermia:
Mild
Moderate
Severe
b) Mild – 90-95ºF
c) Moderate – 82-90ºF
d) Severe below 82ºF
1) Normal mental status with shivering.
2) Functioning normally.
3) Able to care for self.
4) Estimated core temperature 35 to 37°C (95 to 98.6°F).
Cold stressed (not hypothermic)
1) Alert, but mental status may be altered.
2) Shivering present.
3) Not functioning normally.
4) Not able to care for self.
5) Estimated core temperature 32 to 35°C (90 to 95°F).
Mild hypothermia
1) Decreased level of consciousness.
2) Conscious or unconscious, with or without shivering.
3) Estimated core temperature 28 to 32°C (82 to 90°F).
Moderate hypothermia
1) Unconscious.
2) Not shivering.
3) Estimated core temperature <28°C (<82°F).
Severe/profound hypothermia
Vaporization of water through both insensible losses and sweat
Evaporation
Emission of infrared electromagnetic energy
Radiation
Direct transfer of heat to an adjacent, cooler object
Conduction
Direct transfer of heat to convective currents of air or water
Convection
What are the most common mehcanisms of accidental hypothermia
- Convective and conductive heat loss
Demonstrates tachypnea, tachycardia, initial hyperventilation, ataxia, dysarthria, impaired judgment, shivering, and so-called “cold diuresis
Mild hypothermia
1) CNS depression, drop in heart rate and cardiac output, hypoventilation, and hyporeflexia
2) At lower ends of temp, loss of shivering, dysryhtmias (A fib), and dilated pupils below 29ºC
Moderate hypothermia
1) Pulmonary edema, oliguria, hypotension, bradycardia, ventricular dysrhythmias. (V fib/tach/asystole)
2) Loss of oculocephalic reflexes
Severe hypothermia
If vital signs are inconsistent with the degree of hypothermia, what should be considered
Alternative dx
Hypothermic patients are extremely sensitive to and prone to what
Sensitive tomovement and prone to arrhytmias (V Fib)
Rad/Lab studies for hypothermia
1) Fingerstick glucose*
2) Electrocardiogram (ECG) * (Osborne Waves)
3) Basic serum electrolytes, including potassium and calcium
4) BUN and creatinine
5) Serum hemoglobin, white blood cell, and platelet counts
6) Serum lactate
7) Fibrinogen
8) Creatine kinase (CK)
9) Arterial blood gas, uncorrected for temperature, in ventilated patients
10) Chest radiograph (take care to avoid jostling the patient)
Management of hypothermia
(a) ABC
(b) Prevent further heat loss
(c) Rewarming
(d) Treatment of complications
Rewarming of hypothermia
(a) Mild hypothermia is treated with passive external rewarming
(b) Moderate and refractory mild hypothermia are treated with active external rewarming
(c) Severe (and some cases of refractory moderate) hypothermia is treated with
active internal rewarming and possibly extracorporeal rewarming
factors associated with death within 24 hours of presentation included the following
1) prehospital cardiac arrest,
2) low or absent blood pressure on presentation,
3) elevated BUN and
4) the need for endotracheal intubation.
5) Outcome did not correlate with core temperature at presentation
