UMEM Educational Pearls

A 50yo man found dow in the snow was brought into our ER last week in cardiac arrest with a bladder temperature of 21° C. Let’s warm him up!

• Passive external warming (good for mild hypothermia > 34° C):  remove all wet clothing, use warm blankets, hot chocolate.
• Active external rewarming (Used for temp between 30-34° C): Radiant heat, electric blankets, Bair-Hugger. Disadvantages: “core temperature after drop” theory: drop in core temp because of peripheral vasodilatation. Therefore, focus on warming the chest and torso area.  May not occur with certain warming techniques.
• Active core rewarming (<30 °C, above techniques and several other options):

1. Heated humidified oxygen via mechanical ventilation at 42-46°
2. IV normal saline warmed to 41-43° C
3. Cardio-pulmonary bypass: 1-2° C increase every 5 minutes
4. ECMO (best option in cardiac arrest): Up to 4-6° C/hr. VV or VA ECMO. Provides Cardio-pulmonary support. Can continue CPR while placing a cannula.
5. CVVH: less costly, more available, 1-4°C/hr. Case reports only. 
6. Artic Sun; external rewarming pads: used in hypothermia protocols. Easy to use. Case reports only.

• Other methods (use if other methods are unavailable):

1. Pleural irrigation: one chest tube in the mid-clavicular line w saline at 42° and another chest tube in the post-axillary line and connected to a pleurovac.
2. Peritoneal lavage: 8 Fr catheter into the peritoneum using a standard paracentesis method. Use 40-45° C dialysate.
3. Gastric, bladder, colonic irrigations

We were able to get ROSC with CPR and ACLS and then used Artic Sun to re-warm successfully.

Other tips/tricks:

• Continue CPR while rewarming (This is debatable: monitor ECG for new rhythms)
• How warm is “warm and dead”? Probably around 32°C
• How fast to rewarm?  Would warm quickly in cardiac arrest and then 1-2° C/hr thereafter; (No good evidence here)
• Arrhythmias corrected by rewarming (bradycardia etc); no need for pacing
• Up to three defibrillations for V. fib/V. tach; hold if no benefit
• Can give epinephrine per ACLS protocol but would be cautious with further dosing
• Pressors: can use epinephrine drip cautiously for hypotension
• Cisaturacurium for paralysis w/ sedation to prevent shivering
• Rule out hypoglycemia, adrenal insufficiency, hypothyroidism, sepsis if patient does not rewarm as expected!
• Avoid IJ lines or irritating the myocardium with a guidewire.
• K>12 mmol /L: consider termination of CPR

Attachments

1402111256_nejm_hypothermia2012.pdf (581 Kb)