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Flashcards in Environmental Emergencies 2 Deck (27):
1

Frostbite results from?

Pathophysiology
Tissue destruction due to? 3

1. Results from the freezing of tissue—it is a disease of morbidity, not mortality.

2. Pathophysiology
Tissue destruction due to:
-Immediate cold-induced cell death
-More gradual development of localized inflammation & tissue ischemia
-Made worse in the setting of thawing followed by refreezing

2

Describe classes 1-4degree frostbite?

1st degree:
central area of pallor and anesthesia of the skin surrounded by edema (superficial)

2nd degree:
blisters form containing clear or milky fluid surrounded by edema/erythema within 24hrs (superficial)‏

3rd degree:
injury deeper then 2nd degree and blisters are hemorrhagic, progressing to black eschar over several weeks (deep)‏

4th degree:
extends to muscle and bone, involves complete tissue necrosis (deep)‏


Superficial corresponds to 1-2 degree
Deep tissue frostbite corresponds to 3-4 degree

3

Frostbite presentation? 4

1. Patient c/o cold, numbness, and clumsiness of the affected area.
2. Skin may be insensate, white or grayish-yellow in color and hard or waxy to touch.
3. Bullae may be present.
4. Cases of delayed presentation eschars or signs of tissue necrosis may be present

4

1. Dx studies are best for what purpose with frostbite?

2. Which one?

3. What is the goal?

Generally made clinically
1. Diagnostic studies are helpful in determining the existence of comorbidities and extent of frostbite injury
2. Technetium (tc)-99 scintigraphy is used to predict long-term viability of affected tissue.

3. The goal is to allow earlier debridement or amputation of dead or dying areas while leaving viable tissue intact

5

Frostbite Treatment
Prehospital: 5

1. Remove wet clothing
2. Avoid walking on frostbitten feet
3. Do not rewarm if there is a possibility of refreezing
4. Do not rub frostbitten areas
5. Avoid the use of stoves or fires to rewarm

6

Frostbite Determine as many prognostic factors as possible:
8

1. Temperature and wind velocity
2. How long was extremity frozen
3. If thawed, did an refreezing occur
4. Was there any self-treatment, such as rubbing with now or use of aloe vera cream or ibuprofen
5. Were recreational drugs or alcohol involved
6. Any predisposing medical conditions
7. Tetanus prophylaxis
8. Topical aloe and ibuprofen limit inflammation and should be used unless contraindicated.

7

Frostbite Treatment--Hospital
Rapid rewarming techniques? 4

1. Waterbath heated to 40-42C
2. Dry heat difficult to regulate
3. Thawing usually completed 15-30 min

4. Application of bulky dressing, elevation, splinting

8

Managing blisters from frostbite?

1. large nonhemorrhagic bullae?

2. Hemorrhagic bullae of comparable size and location?

3. Minor bullae?

1. Drain, debride and bandage large nonhemorrhagic bullae that interfere with movement.

2. Hemorrhagic bullae of comparable size and location are drained by aspiration, but not debrided.

3. Minor bullae should be left intact

9

1. In patients at high risk for life-altering amputation (eg, multiple digits, proximal amputation), without contraindications to the use of tPA, who present within 24 hours of injury, treatment with what?

Clinicians must discuss the relative risks and benefits of thrombolytic treatment with the patient and obtain informed consent.

Treatment with thrombolytics assumes the patient is willing to accept a small risk of potentially catastrophic bleeding in return for a greater likelihood of retaining functional digits or limbs.

2. Surgical consultation:
May require what? 4

1. intra-arterial tPA plus intra-arterial heparin in consultation with a center experienced in the use of such treatment for frostbite.

2.
-May require long term wound care
-Daily hydrotherapy
-Repeated tissue debridement
-Escharotomy and possibly delayed amputation

10

Frostibite complications
1. short term? 3
2. long term? 3

1. Short-term
-Infection
-Gangrene
-Autoamputation

2. Long-term
-Hypersensitivity to the cold w/ increased risk for developing frostbite again
-Chronic parasthesias to affected area
-Decreased sensation to touch when the hands are involved

11

What are the two different types of heat exhaustions?

1. Water depletion: inadequate fluid replacement by individuals working in a hot environment—can progress to heatstroke

2. Salt depletion: large volumes of thermal sweat are replaced by water with too little salt

12

1. Water depletion causes?

2. Salt depletion causes? 2

1. Hypovolemia

2.
-Hyponatremia,
-hypochloremia

13

Heat Exhaustion
1. Nonspecific symptoms? 3

2. Clinical manifestations? 4

1. Non-specific symptoms
-Weakness, malaise, fatigue
-Headache, lightheadedness, dizziness
-Nausea, vomiting

2. Clinical manifestations
-Hypotension
-Tachycardia, tachypnea
-Diaphoresis
-Syncope

14

Heat Exhaustion
Tx? 4

1. Cool environment
2. Volume and electrolyte replacement
3. Mild cases – oral replacement
4. Moderate cases

15

Moderate cases of heat exhaustion? 2

1. 1-2 liters of saline solution
2. Guided by serum electrolytes

16

1. What is Heatstroke?
2. Elevation of body temp over?
3. With the elevation in temperature, cellular damage occurs…. the tissue damage is affected by what? 4

1. Heatstroke is a life-threatening emergency that occurs when homeostatic thermoregulatory mechanisms fail.

2. > 40.5C (105F)

3.
-Body temp
-Exposure time
-Work load
-Tissue perfusion

17

Heatstroke - Pathophysiology

CNS dysfunction with the occurrence of cerebral edema is common?
5

1. Ataxia
2. Irritability,
3. confusion
4. Bizarre behavior,
5. combativeness

18

Heatstroke - Pathophysiology
1. Greatly increases skin blood flow. Why?

2. If severe heat stress continues? 3

1. Functional hypovolemia compensated by vasoconstriction of the splanchnic & renal vasculature

2.
-Splanchnic vasoconstriction will fail
-Heated core blood increases ICP
-Decreases mean arterial pressure

19

Heatstroke….Diagnosis
5

1. Exposure to heat stress, endogenous or exogenous
2. Signs of severe CNS dysfunction
3. Core temp usually above 104.9F (40.5C)
4. Dry, hot skin, but sweating may persist
5. Marked elevation of liver transaminases

20

How heatstroke can kill? 3

1. Vascular shock
2. Irregular pulse
3. Kidney failure

21

Heatstroke….Treatment
Management of ABC’s
5

1. High flow 02,
2. cardiac monitoring, pulse ox
3. Primary survey
-Cooling is the immediate goal: once the patient arrives at the hospital—
4. clothes should be removed and
5. rectal thermostat probe inserted for continuous temperature monitoring


22

Heat Stroke….Treatment
Cooling techniques?
5

1. Evaporative cooling
2. Cold-water immersion
3. Ice packing
4. Cold gastric lavage
5. Cold peritoneal lavage

23

Heat Stroke Treatment
1. What is evaporative cooling?


2. Disadvanatges? 2

1. Positioning fans close to the completely undressed patient then spraying water on the patient

2. Disadvantages
-Shivering
-Inability of cardiac electrodes to adhere to the skin

24

Heat Stroke Treatment:
1. What is immersion cooling?
2. Ice packs where?
3. Cold water gastric lavage: placement of what?
4. Cold water peritoneal lavage is also used in what other cases?

1. Immersion cooling
-Place undressed patient in a tub of ice water deep enough to cover the trunk and extremities

2. Ice packs to neck, groin, axillae

3. Cold water gastric lavage
-Placement of NG tube

4. Cold water peritoneal lavage
Also used in some cases of AMI and ischemic CVA to mitigate myocardial and cerebral tissue damage

25

Heat Stroke
1. Whatever method used, cooling efforts should be discontinued when the rectal temperature reaches what?

2. Continued cooling below this temperature may lead to what?

1. 40C (104F).

2. hypothermia.

26

Heat Stroke
1. Seizures and aspiration are common so what is essential?
2. what else is common?
3. Fluid administration needs to be done carefully as some patients can develop what?
4. Tachyarrhythmias often occur and usually resolve with what?

1. airway control

2. Hypotension

3. pulmonary edema

4. cooling.

27

Heat Stroke

Foley catheter
1. IV fluids….NS at ____ml/hr
2. Labs: ? 8
3. ________ is common—especially in persons with exertional heatstroke and can get worse with rewarming
4. Agitation & seizures are best treated with what?


Admission…. transfer to higher level of care if necessary

1. 250

2.
-ABG’s,
-CBC,
-CMP,
-liver enzymes,
-lactate dehydronase,
-creatinine phosphokinase,
-uric and lactic acid,
-PT and PTT

3. Acidosis

4. short-acting benzodiazepines