Hypothermia

•  definition core temperature under 35C 
• Evaluated for severity of hypothermia:
  • Mild (33 – 35),  clinically usually seen altered mental status.
  • Moderate (30-32), decreased level of consciousness , 32 J waves
  •  severe (22-28) ,  low BP, arrhythmias
  • Profound (less than 20),  asystole. Lowest survivable 13. bradycardia is to be expected with hypothermia. If tachycardic, consider concurrent alternative process.Atropine not affected.
• Evaluated for potential causes:
  • Decreased heat production ( POC Cucos, TSH)
  • Increased heat loss (exposure) 
  • Impaired thermoregulation (age, alcohol ) 
  • Infection,  less likely when clear alternative because for hypothermia however will work for findings of source of infection on exam.
•   diagnostically
  • •  point of care glucose
    •  ABG
    •  ABC, CMP, lipase , calcium, magnesium , coags
    •  considered the selective utility of:
      •  thyroid studies
      •  cardiac biomarkers
      •  serum cortisol levels
      •  liberal use of radiography (CXR, abdominal CT, spinal CT)  given concurrent possible trauma and sequelae of ileus, pancreatitis Oracle trauma secondary to hypothermia
• therapeutically:
  • IVF usually dehydrated and cold diuresis
  •  monitored electrolytes Jorenby warming. Replete potassium if <  3
  •  D5 normal saline 500 mL
  •  intubation nasotracheal way if trismus
  •  IVF at 40 to 42 (1 L place in microwave for two minutes) (avoid LR)
  •  if dysrhythmia, difibribullate
    •  if unsuccessful, warm to greater than 30 then resume defibrillation
  • If bradycardic, transcutaneous pacing
  •  if failure to rewarm, and considering:
    • adrenal cortical insufficiency, hundred milligrams IV hydrocortisone given.
    •  thyroid dysfunction given 500 g levothyroxine 
    • Empirical anabiotics
  • Goal rewarming 0.5 to 2C per hour unless dysrhythmia then faster. 
    • Passive rewarming utilized ( bear hugger)
    • active rewarming utilized  when temperature under 32 ( considered the risks however benefits outweigh risks for thermal injury to hypoperfused skin)
  •  if available, would use extracorporeal blood warming:
    • Venovenous circuit, hemodialysis, continuous AV rewarming, cardiopulmonary bypass 
• Disposition:
  •  if temperature 32 to 35 , hemodynamically stable and safe disposition patient is appropriate for discharge. 
  • If under 32, well admit
  •  transfer to higher level of care