Cooling Therapy – Risks and Complications
Therapeutic hypothermia for hypoxic-ischemic encephalopathy (HIE) involves a moderate treatment where a newborn baby’s core body temperature is measured by a rectal probe or esophageal probe and cooled down to around 33 degrees Celsius for up to 72 hours. The body temperature is then slowly rewarmed.
Get A 100% Free CASE EvaluationCooling therapy can be applied via two distinct methods:
- By selective head cooling system. With this method, the temperature is usually cooled to between 34 – 35 degrees C.
- By whole body cooling where the core temperature is cooled down to between 33 – 34 degrees C.
There are several highly technological devices that can be used for whole body cooling, where the idea is to circulate cool fluid contained in a cooling blanket or mattress that is wrapped around the baby. The baby’s temperature is monitored on a continuous basis during the treatment.
At present, there is just one head cooling device that circulates fluid in the cap, and the cap is wrapped around the infant’s head. Again, the infant’s core temperature is monitored continuously and is maintained by manually changing the cap temperature or adjusting the environmental temperature.
Other than high-tech devices, there are a few other methods in which this type of treatment can be administered. Ice packs or gel packs placed around the baby’s head, phase changing materials wrapped around the baby’s body, and cooling fans that provide adequate air circulation around the newborn are all methods that have been used successfully in low-resource settings.
Duration of Treatment
Currently, the optimal duration is unknown, but common consensus tends to be between 48 hours to 72 hours, with most treatments lasting for 72 hours.
The speed at which the infant should be rewarmed is somewhat controversial and tends to vary between increasing the rectal temperature by half a degree Celsius every hour to every four hours. The consensus, though, is that the rewarming process must be slow. Most clinics tend to rewarm newborn babies by half a degree Celsius every two hours.
The Complications and Risks of Cooling Therapy
Like most therapies, there are a few complications that can occur when therapy is undertaken.
It must first be noted that the nurse’s position at the bedside is the primary line of intervention when complications arise in a newborn baby with HIE who is undergoing cooling therapy. Physicians and nurses should have a thorough understanding of what to anticipate as well as the fleeting changes in baseline monitoring parameters are necessary.
Blood Clotting
There are a number of complications that may occur as a result of asphyxia and hypothermia. Further, bradycardia, or an abnormally slow heart rate, may occur but tends to subside when the baby’s core temperature is slightly warmed. It is further necessary to monitor for any other cardiac arrhythmias that might occur.
Another complication known to occur is hypotension, which is usually secondary to abnormal heart rhythms and reduces stroke volume. A reduced blood flow has also been reported in hypothermic infants, which can pose a risk of micro embolism – blood clotting.
It is also worth mentioning that blood clotting tends to be prolonged during hypothermia. However, if the clotting is normal prior to therapy, a baby should not experience complications as a result of the therapy. However, it is not unusual for an infant lacking oxygen to have abnormal blood clotting secondary to an injury to the liver. Therefore, monitoring of liver function and other clotting should be conducted at regular intervals.
Nurses should be aware of the physical signs of clotting, which include:
- Oozing from puncture sites
- Gastric secretions
- Bloody urine
- Endotracheal secretions
Overall, any baby that has had a traumatic delivery must be specially monitored for bleeding, especially brain hemorrhaging.
Abnormal Sugar/Salt Levels
A baby’s electrolytes should also be closely monitored to maintain reference ranges. Bedside experts ought to be knowledgeable when it comes to normal laboratory value. It is important to monitor the baby’s blood glucose levels to avoid excess at either end of the spectrum and be able to meet the baby’s basic metabolic and nutritional requirements.
A Few Side Effects of Cooling Therapy to Be Aware Of
There are few side effects associated with cooling therapy, and such side effects tend to resolve on their own or return to baseline with the return to a warmer core body temperature. Any side effects that do occur do not tend to interfere with the management of providing the therapy. Overall, studies have found that the benefits of cooling therapy far outweigh the potential side effects.
The Safety of Hypothermia and Using Cooling in Premature Babies
Mild hypothermia tends to be safe and does not have any serious side effects.
However, hypothermia is associated with an increased risk of death in premature infants. The data is controversial, though, with some studies reporting no effect and others showing improvement. To date, there is no evidence that the cooling method offers any benefit to babies who are born prematurely.
While no parent wants to think of their baby being born with brain injury, it is something that must be prepared for, and the risks and complications of cooling therapy understood.