Cooling in Peds Arrest

Kathleen Stefanos MD and Anand Swaminathan MD

● Therapeutic hypothermia is contraindicated in hemorrhage, traumatic cardiac arrest and intracranial hemorrhage.

● Therapeutic hypothermia should be considered after ROSC in neonates greater than 35 weeks, greater than 1800g with signs of neonatal distress and hypoxic ischemic encephalopathy.

● Some studies have shown no difference when cooled to 33°C versus 36°C. It is important to prevent hyperthermia.



● Why does therapeutic hypothermia improve outcomes?

o Therapeutic hypothermia decreases oxygen and glucose requirements. It decreases disruption of the blood brain barrier, decreasing cerebral edema. It decreases metabolism overall (a decrease of about 6-10 percent for every degree Celsius).

o On a cellular level, there is decreased free radical formation, decreased pro-inflammatory cytokines and the emergence of cold shock proteins which decrease apoptosis and allow for cell growth.

● When should we not use therapeutic hypothermia? We don’t use it in hemorrhaging patients, traumatic cardiac arrests or patients with intracranial hemorrhage. Hypotensive patients on vasopressors are not good candidates for therapeutic hypothermia as it may worsen hypotension. Therapeutic hypothermia decreases anti-inflammatory cytokines which is not desired in severe sepsis. Not to be used in pregnancy.

● Consider therapeutic hypothermia post arrest with ROSC in neonates greater than 35 weeks, greater than 1800g, with signs of neonatal distress (vital signs or pH) and signs of hypoxic ischemic encephalopathy.

o What should we do? Target 32°C to 34°C.

o Therapeutic hypothermia will save a life or protect the brain in 1 of every 5-10 babies. This is a potentially life-saving treatment that we don’t talk about much. We don’t have to do it immediately; we have a window of about 6-10 hours.

o You need to transfer these patients to a cooling center. Cooling en route can lead to fluctuations and is not ideal. Transport as soon as possible. Not all NICUs have the capability to do therapeutic hypothermia.

● The TTM trial found no difference when patients were cooled to 36°C versus 33°C.

o Nielsen, N et al. Targeted temperature management at 33°C versus 36°C after cardiac arrest. N Engl Med. 2013 Dec 5;369(23):2197-206. DOI: 10.1056/NEJMoa1310519

● A study involving 260 children found no difference in survival or neurologic outcome when cooled to 33°C versus 36°C.

o Moler, FW et al. Therapeutic hypothermia after out-of-hospital cardiac arrest in children. N Engl J Med. 2015 May 14;372(20):1898-908. PMID: 25913022

o Despite most children arresting from respiratory causes, the data in pediatric patients appears similar to that in adult populations.

o They wanted to enroll over 900 patients but were only able to enroll a third of the desired number. About 72% were from respiratory causes and 14% cardiac. The average age was 2.

o There was a 10% improvement in survival in the hypothermia group and 8% improvement in neurologic outcome. Infections were slightly increased.

● If it was your child, what would you do? It is not statistically significant but many would opt for therapeutic hypothermia.

● We must avoid hyperthermia. We can target lower temperatures but if the patient is unable to tolerate it, you can go higher.

● The Sarnat criteria are a classification scale for grading severity of hypoxic-ischemic encephalopathy of the newborn. This takes into account alertness, muscle tone, seizures, pupils, respiration and duration of symptoms. This can help guide the decision to initiate therapeutic hypothermia.

● How long should we cool these patients? The original animal trials cooled for 72 hours but some are cooling for only 24 hours.

● How should you do it? Any way you can. Place ice packs to the neck, axilla and groin. Then place your temperature probe and cooling device. When you reach the desired temperature, remove the ice packs. Ice packs can cause localized burns and fat necrosis.

Don’t give these patients drugs that cause QT prolongation. The QT prolongation associated with hypothermia has never been shown to cause Torsades but you should still avoid prolonging the QT interval further.

Don’t let the patient get above 37°C.


Don’t worry about bradycardia. 60-80 bpm in pediatric patients is perfectly acceptable.

Monitor the potassium. The potassium will drop early on during cooling. If the patient will be in your emergency department for more than 4 hours, check the potassium. Your goal is greater than 3.5. Replete as needed.

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