RISK FACTORS
β’ Malnutrition
β’ Cold water immersion
β’ Exposure to high winds
β’ Homeless
β’ Vehicle breakdown
β’ Outdoor workers
β’ Trauma victims (especially head)
β’ Alcohol consumption
β’ Mental illness; Alzheimer disease
β’ Drug intoxication (barbiturates, phenothiazines, cyclic
antidepressants, parasympatholytics, benzodiazepines,
narcotics)
APPROPRIATE HEALTH CARE Inpatient (emergency room or intensive care)
GENERAL MEASURES
. Establish ABCs of basic life support; establish airway, intubate if necessary. Give warm humidifi ed oxygen
(42-46 DEGREE C). Correct metabolic acidosis.
. Evaluate for frostbite and other trauma
. Rewarming
. Dependent on severity of hypothermia
. Warm center of body first
. Rate of rewarming should be 0.5-2 DEGREE C/hour. More rapid rewarming can cause ventricular fibrillation and hypovolemic shock.
. With all patients
. Remove wet garments
. Protect against heat loss and wind chill
. Maintain horizontal position
. Monitor core temperature and cardiac rhythm
. Mild hypothermia
. Passive rewarming (wrap in heated blanket or clothing)
. Administration of heated (43 DEGREE C) IV solutions (5DNS)
. Warm fluids may be given if fully alert
. Moderate hypothermia
. Active external rewarming
. Heated blankets; heating pads
. Radiant heat sources
. Alcohol-circulating blankets
. Severe hypothermia
. Active internal (core) rewarming
. Peritoneal dialysis
. Gastrointestinal, colonic, or bladder lavage with warm
fluids (43 DEGREE)
. Heated intravenous fluids
. Heated humidifi ed oxygen
. Thoracic cavity lavage (43 DEGRE)
. Extracorporeal blood rewarming
. Cardiac arrhythmias
. Atrial fibrillation and sinus bradycardia are common, but patients usually convert to normal sinus rhythm
with rewarming
. Transient type ventricular arrhythmias should not be treated. If treatment is required, bretylium is recommended.
. If cardiac pacing required, preferable to use external noninvasive pacemaker
. Sepsis bacterial infections
. In infants - signs may not be evident, initiate treatment with broad-spectrum antibiotic until culture
results are available
. Older children and adults - if no signs, can usually wait for culture results
. Diabetic adults - consider prophylactic antibiotic coverage
ACTIVITY Bedrest. Because of the cold, heart is irritable and susceptible to arrhythmias. Take special
care in moving and transporting.
DIET Warm fluids only, if alert and able to swallow
DRUG(S) OF CHOICE
β’ For sepsis or bacterial infections - antibiotics based on site and etiology. Prophylactic antibiotics are not
indicated.
β’ If ventricular fibrillation requires treatment, bretylium, 5 mg/kg, may be helpful. Magnesium sulfate, 100 Mg/kg, is also effective.
β’ For hypoglycemia, D50W at a dose of 1 mg/kg IV
β’ Thiamine, 100 mg IV, should be given to any alcoholic or cachectic patient
β’ Naloxone, 2.0 mg IV, should be given to any patient with a depressed level of consciousness
β’ Levothyroxine 150-500 MICRO GM IV for hypothermic myxedema
β’ For severe acidosis - sodium bicarbonate
Precautions:
β’ If the patient fails to respond to the initial three defibrillation attempts or initial drug therapy, subsequent
defibrillations or additional boluses of medication should be avoided until core temperature > 30Β°C. When
temperature > 30Β°C, IV medications are indicated, but at longer than the standard intervals.
β’ Avoid vasopressors because of arrhythmogenic potential and delayed metabolism
β’ To prevent fl uid overload, IV fl uids should be slowlyadministered because of the decreased cardiac output
β’ Avoid lactated Ringerβs solution because of decreased lactate metabolism
PATIENT MONITORING
. During acute episode
. Lab work repeated frequently (with particular attention to electrolytes and glucose)
. Continuous cardiac monitoring
. Urinary output monitoring
. Temperature monitoring
. Follow blood gases, both corrected and uncorrected
. Following acute episode
. Continued therapy for any underlying disorder
PREVENTION/AVOIDANCE
. Appropriate clothing for cold weather, with particular attention to head, feet and hand coverings
. If walking or climbing in cold climate, carry survival bags lined with space blankets for use if stranded or
injured
. Avoid alcohol, especially if anticipating exposure to cold weather
. Alertness to early symptoms and initiating preventive steps, e.g., drinking warm fluids
. Adequate heat in the home
. Review patients medications that may predispose to hypothermia (e.g., neuroleptics, sedatives, hypnotics,
tranquilizers) and decrease dosage or discontinue if appropriate and feasible
. Referral of patient to social service agency for help with adequate housing, heat or clothing
POSSIBLE COMPLICATIONS
. Cardiac arrhythmias
. Hypotension secondary to marked vasodilatation of rewarming
. Hyperkalemia
. Hypoglycemia
. Rhabdomyolysis
. Bladder atony
. Pneumonia (aspiration and broncho)
. Pulmonary edema
. Pancreatitis
. Peritonitis
. Gastrointestinal bleeding
. Acute tubular necrosis
. Intravascular thromboses
. Metabolic acidosis
. Gangrene of extremities
. Compartment syndromes
EXPECTED COURSE/PROGNOSIS
. Mortality rates are decreasing for hypothermia due to increased recognition and advanced therapy. Mortality
usually dependent upon the severity of underlying cause of hypothermia.
. In previously healthy individuals, recovery is usually complete
. Mortality rate in healthy patients < 5%
. Mortality rate in patients with co-existing illness > 50%