In continuing our podcast interview with Jennifer Norgaard, a NICU Clinical Nurse Specialist at a level IV NICU in California, she explained that while hypoxic-ischemic encephalopathy (HIE) may not be preventable, therapeutic hypothermia (TH), or targeted temperature management (TTM), is a promising treatment for neonates. She indicated that It provides a way to reduce brain cell damage, by cooling eligible infants within 6 hours of birth to a body temperature of 34º C +/- 0.5º for 72 hours before slowly rewarming them to normal temperature.(3)
Criteria for Inclusion in Therapeutic Hypothermia Treatment
Norgaard's comments were supported by this Journal of Clinical Neonatology article(1) and this Neonatal Network article(3).
To be included in the protocol for use of therapeutic hypothermia, the infant must present with the following criteria:
- Born at 36 weeks or greater gestational age,
- Apgar scores at or below 5 at 10 minutes after birth
- Continued need for resuscitation and/or ventilation after 10 minutes
- Cord pH or arterial blood gas pH less than or equal to 7.0
- Base deficit of equal or greater than 16 mEq/L within 1 hour of birth
- Abnormal neurological exam
If some or all of these signs are present, a clinician will conduct a follow-up exam to determine if the induction of hypothermia may be beneficial. Therapeutic hypothermia is recommended for infants showing moderate to severe neurological issues.
While hypothermia shows promising results for many neonates with HIE, there are also HIE patients for whom this therapy should not be used. Certain neonates may be at too high of a risk for this treatment, while others may not display a strong enough benefit to warrant these treatment risks, and should pursue alternative therapies.
Some of the expressed exclusion criteria include those neonates who:
- Are more than 6 hours old
- Were born at a weight of less than 1800gm
- Have life-threatening respiratory or vascular system abnormalities
- Are presenting with congenital malformations or chromosomal abnormalities
- Appear to have limited or minor neurological damage
- Are less than 36 weeks in gestational age
When used with eligible neonates, therapeutic hypothermia provides a valuable tool for restricting damage from oxygen deprivation at birth with minimal side effects.(2)
1. Rafat Mosali, MD; "Whole Body Cooling for Infants with Hypoxic-Ischemic Encephalopathy", J Clin Neonatol. 2012 Apr-Jun; 1(2): 101–106.
2. NIH News Release, "Cold Treatment Protects Against Infant Disability & Death from Oxygen Loss", October 12, 2005, NICHD Archive
3. Tiffany Harriman, MSN, RNC-IC; Wanda T. Bradshaw, MSN, RN, NNP-BC; Stephanie M. Blake, DNP, RN, NNP-BC. " The use of whole body cooling in the treatment of Hypoxic-Ischemic Encephalopathy", September/October 2017; 36(5): 273-279.