Hypothermia Post Cardiac Arrest (cuh)
Indications
Adult patients with persistent coma following return of spontaneous circulation post cardiac arrest due to ventricular fibrillation/tachycardia
Consider in patients with return of spontaneous circulation post cardiac arrest due to asystole.
Contraindications
- Age <18
- Pregnancy
- Systolic blood pressure<90mmHg
- Pre-existing coagulopathy
- Suspected other causes coma e.g. trauma, overdose, CVA
Cooling Technique
- Core temperature (rectal or urinary catheter) should be measured throughout the period of cooling
- Cool the patient as soon as possible to 32-34°C and sustain this temperature for 24 hours from the time of the event.
- All patients should have reached the target temperature within four hours of initiating cooling. This is achieved initially by any combination of the following.
- Applying ice packs to the patients head, neck, torso and limbs (remove when temperature hits 330c).
- Infusing 20-30mls/kg of refrigerated saline over 20-30mins if volume status permits.
- Applying a cooling device (Blanketroll III, available in ICU, see protocol for instructions on use)
- Midazolam and Vecuronium should be administered as required to prevent shivering.
- Monitor patient for arrhythmias.
- Maintain target temperature for 24 hours by means of a cooling device (available from general ICU).
- Monitor electrolytes, ABGs and coagulation every 6 hours during cooling and rewarming phases
- Monitor skin for breakdown and thermal burns
- Use pillow case or other material between blanket and patients skin if required.
- After 24 hours the patient should be warmed slowly using the rewarming cycle on the cooling device.
- Rewarming should occur no faster than 6-8 hour.
- Calcium levels may fall with cooling.
- Magnesium levels may fall with cooling.
- Potassium levels may rise or fall with cooling.
- Glucose levels may rise or fall with cooling.
Re-warming procedure
- Re-warming is done gradually over minimum of 6-8 hours after completion of the 24 hour period of cooling. Use cooling device to rewarm patient. Do not remove the blanket to allow the patient to rewarm passively.
- Core body temperature is slowly increased at the rate of 0.5 ºC per hour over a 6 hour period.
- Each hour increase the cooling blanket SETPOINT temperature by 0.5ºC (to maximum SETPOINT of 36.5 ºC). Press the TEMPERATURE SET switch, use the up arrow to increase the SETPOINT by 0.50C.
- Press the GRADIENT VARIABLE button. Please refer to Blanketroll III protocol for instructions on use.
- Monitor electrolytes, ABGs and coagulation during and post rewarming.
Monitor closely during and a minimum of 24 hrs post rewarming for:
- Seizures
- Rebound hyperthermia
- Acidosis
- Hypoglycaemia
- Hypoglycaemia
- Hyperkalaemia
- Hypomagnesaemia
- Diuresis/oliguria
- Vasodilatation and hypotension
References
Bernard S, Gray T, Buist M et al. Treatment of comatose survivors of out-of –hospital cardiac arrest with induced hypothermia. NEJM 2002;346:557-63
The Hypothermia after cardiac arrest study group. Mild therapeutic hypothermia to improve the neurological outcome after cardiac arrest. NEJM 2002; 346:459-56
NICE Guideline March 2011 IPG386- Therapeutic hypothermia following cardiac arrest (local copy brief summary)
