Cold Emergencies:
As the temperature drops, the potential for cold temperature to factor in to patient complaints increases. This can mean medical or trauma related occurrences that a a direct result of a cold environment, or it can include situations where an existing problem becomes complicated by a cold environment. In the prehospital setting, all patients should be removed from the cold environment as quickly as is feasible.
I want to discuss a few problems commonly encountered during the winter months.
Slip and Falls:
There is an increase in falls during the winter, I think we can all agree on that. Frozen surfaces on stairs, in driveways, sidewalks, and parking lots, all provide potential for pedestrians to slip and fall. Falls from standing are generally associated with minor trauma, but they can be serious in patients over 65 years of age. This age group has increase incidence of head, spine, and musculoskeletal injuries related to falls from standing height. Spinal immobilization (with a cervical collar) should be considered in all patients over 65 years of age, especially in the presence of any of the following:
Neck or back pain
Spine tenderness
Neurological signs or symptoms
Altered LOA
Suspected drug or ETOH intoxication
A distracting painful injury
Anatomic deformity of the spine.
If a fall involves stairs, we want to be concerned about falls greater than 5 steps for adults, and 3 steps for children. Us your clinical judgement and err on the side of caution.
Frostbite:
Prolonged exposure to subzero temperatures can lead to varying degrees of tissue freezing (which is what frostbite is). Just like a burn, frostbite is classified based upon the depth of cellular freezing.
First degree frostbite: This is partial thickness freezing of the epidermis, and is characterized by redness, and edema of the tissues without blistering.
Second degree frostbite: This is full thickness freezing of the epidermis and dermis, and results in the formation of clear bullae, and numbness that gradually changes to throbbing pain.
Third degree frostbite: This involves freezing of the epidermis, dermis, and sub-dermal tissues. This presents with the additional presence of skin necrosis.
Fourth degree frostbite: This involves freezing of the muscles, tendons, and bone tissues. Skin is mottled, and cyanotic. Eventually the skin takes on a dry, mummified texture.
Treatment of frostbite is similar to that of burns. We want to remove wet clothing, cutting around areas that are frozen to the skin. We we wrap the frozen tissue in dry, sterile dressings and treat pain with analgesics. DO NOT actively rewarm these areas. Rewarming shock is a risk, as is the potential for release of cellular debris, and the byproducts of necrosis, back into circulation. Re-warming should be done in hospital.
Hypothermia:
Hypothermia is defined as a core temperature <35 degrees celsius, and can be classified as mil-moderate, or severe based upon temperature and presentation.
Mild-moderate hypothermia: These patients have a core temperature <35 degrees but >32 degrees celsius. They typically present with pale cold skin, profound shivering, and mild alterations in level of awareness. They are typically tachycardic, tachypneic, and may have elevated BP due to systemic vasoconstriction.
Severe hypothermia: These patients have a core temperature <32 degrees celsius. They present with cessation of shivering, severe alterations in LOC, and may be tachycardic but will progress to bradycardia. Hypotension is also likely due to cold diuresis, and cardiac disturbances. As the myocardial temperature drops, cardiac cells become more irritable. As a result we see a characteristic ecg pattern of bradycardia, that progresses to slow atrial fibrillation, and finally changes to ventricular fibrillation.
Treatment of hypothermia is dependent on the severity of the patient. Patients with mild-moderate hypothermia should be moved to a warm environment, have wet clothing removed, be covered with dry sheets, and have warm packs applied to the axillae and groin. Patients with severe hypothermia need a very cautious approach, as sudden movement or aggressive airway management can trigger ventricular fibrillation. We want to move these patients carefully to the ambulance, remove wet clothes and cover the patient with dry sheets. Active rewarming needs to occur in the hospital. In the event that a hypothermic patient has a cardiac arrest, remember “They aren't dead until they are warm and dead”. Perform a single analysis/defibrillation and then transport rapidly while following BLS CPR protocol (ACLS may apply depending on your local protocol). In hospital, these patients will receive specialized treatment to raise core temperature from 1-6 degrees per hour. Thoracic lavage, warm IV fluids, and heated humidified ventilation are just a few treatments that can be performed in the ED; we need to get the hypothermic patient to definitive care.
Things that we need to look for with hypothermic patients:
There are a few things that can cause or exacerbate hypothermia that we should be asking about.
Alcohol use: ETOH causes vasodilation and rapid heat loss through radiation.
Hypoglycemia: Low blood glucose levels impede the ability of cells to participate in the metabolic process, and therefore inhibits our ability to generate heat.
Medications: Beta-blockers, CCBs, and other cardiac medications can inhibit vasoconstriction and affect the patient's ability to compensate for cooler temperatures.
Street drugs: Many drugs affect the ability of the patient to feel pain, or to notice they are cold. This can cause us problems when we want to determine a timeline as to how long the patient has been in a hypothermic state.
A final word about IV fluids:
Our isotonic IV fluids are room temperature. WE DON'T WANT TO GIVE THIS TO A HYPOTHERMIC PATIENT. Doing so may plummet core temperature further and actually cause harm.
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