Diferencia entre revisiones de «Accidental hypothermia»
(added ecg link) |
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| Línea 9: | Línea 9: | ||
**Anorexia nervosa | **Anorexia nervosa | ||
**[[CVA]] | **[[CVA]] | ||
**[[Head trauma (adult)|Head trauma]] | |||
**Hypothalamic dysfunction | **Hypothalamic dysfunction | ||
**Metabolic failure | **Metabolic failure | ||
| Línea 22: | Línea 23: | ||
*Endocrine | *Endocrine | ||
**[[DKA]] or [[alcoholic ketoacidosis]] | **[[DKA]] or [[alcoholic ketoacidosis]] | ||
**Hypoadrenalism | **[[Hypothyroidism]] | ||
**Hypopituitarism | **[[Adrenal crisis|Hypoadrenalism]] | ||
**Hypopituitarism | |||
**[[Lactic acidosis]] (Sepsis) | **[[Lactic acidosis]] (Sepsis) | ||
*Insufficient energy | *Insufficient energy | ||
**Extreme physical exertion | **Extreme physical exertion | ||
**[[Hypoglycemia]] | **[[Hypoglycemia]] | ||
**Malnutrition | **Malnutrition | ||
*Increase heat loss | |||
**[[Burns]] | |||
**[[Blood transfusions|Massive blood transfusions]] | |||
*Neuromuscular compromise | *Neuromuscular compromise | ||
**Recent birth or advanced age | **Recent birth or advanced age | ||
Revisión del 19:54 25 ago 2015
Background
Definition: Core Temp <35C (95F)
- 50% who die of hypothermia are >65 years old
Swiss Hypothermia Staging System[1]
| Classification | Temperature | Signs/Symptoms |
|---|---|---|
| I / Mild | 32-35°C (90-95°F) | Shivering, awake |
| II / Moderate | 28-32°C (82-90°F) | Shivering, depressed mental status |
| III / Severe | 20-28°C (68-82°F) | unconscious/severely depressed mental status, shivering ceases |
| IV / Profound | <20°C (68°F) | unobtainable VS |
Differential Diagnosis
Impaired thermoregulation
- Central failure
- Anorexia nervosa
- CVA
- Head trauma
- Hypothalamic dysfunction
- Metabolic failure
- Neoplasm
- Parkinson's
- Drugs-Ethanol, Sedatives-hypnotics
- SAH
- Toxins
- Peripheral failure
- Acute spinal cord transection
- Decreased heat production
- Neuropathy
- Endocrine
- DKA or alcoholic ketoacidosis
- Hypothyroidism
- Hypoadrenalism
- Hypopituitarism
- Lactic acidosis (Sepsis)
- Insufficient energy
- Extreme physical exertion
- Hypoglycemia
- Malnutrition
- Increase heat loss
- Neuromuscular compromise
- Recent birth or advanced age
- Impaired shivering
Increased heat loss
- Dermatologic
- Burns
- Exfoliative dermatitis
- Iatrogenic
- Massive fluid or blood resuscitation
- Emergency childbirth
- Heat stroke treatment
- Other
- Carcinomatosis
- Cardiopulmonary disease
- Multisystem trauma
- Shock
Diagnosis
ECG
- Typical sequence is sinus brady > a fib w/ slow ventricular response > v-fib > asystole
- Other ECG findings:
- Osborn (J) wave
- T-wave inversions
- PR, QRS, QT prolongation
- Muscle tremor artifact
- AV block
- PVCs
- Examples
Treatment
General
- Handle pt gently
- V-fib may be induced by rough handling of pt due to irritable myocardium (anecdotal)
- O2
- Hypothermia causes leftward shift of oxyhemoglobin dissociation curve
- IVF
- Reasons:
- Hypothermia > impaired renal concentrating ability > cold diuresis
- Pts are prone to rhabdo
- Intravascular volume is lost due to extravascular shift
- Reasons:
- CPR
- Only perform if pt truly does not have a pulse (unnecessary CPR may lead to V-fib)
- Spend 30-45s attempting to detect respiratory activity and pulse before starting CPR
- Dysrhythmias
- Occur once temp <30C (86F)
- Rewarming is treatment of choice
- V-fib
- May be refractory to therapy until pt is rewarmed
- Attempt a single defibrillation attempt
- If unsuccessful continue CPR and attempt defibrillation again once temp >30C (86F)
- Antibiotics
- Give if suspect sepsis (e.g. hypothermia fails to correct w/ rewarming measures)
- Thiamine
- Consider if Wernicke disease is possible cause of hypothermia (e.g. alcoholic pt)
- Hydrocortisone
- Consider if pt has history of adrenal suppression or insufficiency
- Thyroxine
- Consider if any suspicion for hypothyroidism/myxedema coma
Rewarming
- Passive
- Consider in pt w/ mild hypothermia who is able to generate intrinsic heat
- Techniques
- Removal from cold environment
- Insulation
- Active
- Consider in:
- Moderate-severe hypothermia
- Mild hypothermia in pt who is unstable or cannot generate intrinsic heat
- Failure to respond to passive external rewarming
- May be ineffective in pts w/ poor perfusion or in cardiac arrest
- Techniques
- Rewarm trunk BEFORE the extremities
- Otherwise may lead to hypotension ("core temperature afterdrop")
- Warmed vasodilated peripheral tissue allows cooler blood in extremities to circulate back to core
- Otherwise may lead to hypotension ("core temperature afterdrop")
- Warm water immersion
- Heating blankets
- Radiant heat
- Forced air - Bair hugger
- Warm humidified air
- Rewarm trunk BEFORE the extremities
- Consider in:
- Active Internal
- Consider alone or along with active external warming in:
- Cardiovascular instability / life-threatening dysrhythmias
- Severe hypothermia
- Moderate hypothermia which fails to respond to less aggressive measures
- Techniques
- Heated IV fluids: 65°C > 45°C more efficacious
- If central line is placed avoid irritating the heart
- GI tract lavage
- Bladder lavage
- Pleural lavage
- Peritoneal lavage
- Bypass/ECMO[2]/AV Dialysis
- Heated IV fluids: 65°C > 45°C more efficacious
- Consider alone or along with active external warming in:
Complications
- Aspiration PNA
- DIC/Bleeding
- Clotting factors are less effective
- Ineffective Drugs
- Protein binding increases as body temperature drops, and most drugs become ineffective
- Pharmacologic manipulation of the pulse and blood pressure generally should be avoided
- Orally meds poorly absorbed because of decreased gastrointestinal motility
- Intramuscular route avoided due to poor absorption from vasoconstricted sites