Introduction

When a newborn does not receive enough oxygen or blood flow to the brain around the time of birth, the brain cells begin to die. This condition is called Hypoxic-Ischemic Encephalopathy (HIE), and it is one of the most serious emergencies in newborn medicine.

A Therapeutic Hypothermia Device, also called a neonatal cooling device, is the only proven treatment that can slow down and reduce this brain injury. It works by carefully lowering the baby's body temperature to a specific, controlled level, which slows the process of brain cell death and allows time for recovery.

This treatment has been shown in multiple large clinical trials to significantly reduce death and long-term disability in affected newborns when started on time.

Purpose of the Device and Where It Is Used

Primary Purpose

The therapeutic hypothermia device lowers and maintains the newborn's core body temperature to 33 to 34 degrees Celsius (91.4 to 93.2 degrees Fahrenheit) for a period of 72 hours. This controlled cooling reduces the metabolic rate of brain cells, slows the chemical processes that cause cell death, and gives the brain an opportunity to recover.

Why Timing Matters

Brain injury after an oxygen-depriving event happens in two stages. The first stage occurs during the event itself. After a brief recovery window, a second wave of injury occurs due to inflammation and chemical reactions in the brain cells. Cooling therapy works by interrupting this second wave. It must be started within 6 hours of birth to be effective.

Where These Devices Are Used

• Neonatal Intensive Care Units (NICUs) of tertiary-level hospitals
• Specialized children's hospitals with neonatal neurology support
• Regional referral hospitals with cooling capability
• In transport settings (passive cooling) when transferring a newborn to a cooling center

In hospitals without cooling equipment, passive cooling (removing clothing, turning off warmers, monitoring temperature closely) is started while arranging emergency transfer to a capable facility.

Who Is Eligible for Cooling Therapy?

Therapeutic hypothermia is recommended for newborns who meet specific criteria. These are assessed by the treating medical team.

Who Should Not Receive This Treatment

• Babies born before 35 weeks gestation (evidence of benefit is lacking)
• Babies with major congenital abnormalities
• Uncontrolled active bleeding
• Babies for whom no further intensive treatment is planned
• Severe intrauterine growth restriction in some cases (assessed individually)

Types of Therapeutic Hypothermia Devices

There are two main methods of delivering cooling therapy, each using a different type of device.

1. Whole-Body Cooling Device

A specially designed blanket or mattress is placed around the baby's body. Cold water circulates through the blanket and lowers the entire body's temperature. A temperature probe (inserted rectally or in the esophagus) constantly monitors the baby's core temperature, and the device automatically adjusts the water temperature to maintain the target of 33 to 34 degrees Celsius.

2. Selective Head Cooling Device

A cooling cap is placed on the baby's head and circulates cold water to cool the brain specifically. The body temperature is mildly lowered using a radiant warmer set to a lower level. The target temperature is slightly higher at 34 to 35 degrees Celsius for core body temperature. A scalp check is done every 12 hours to detect any skin irritation from the cap.

3. Passive Cooling (Temporary Measure)

When no cooling device is available, passive cooling is used as a temporary bridge. This involves turning off radiant warmers and incubators, removing clothing and blankets, and closely monitoring the baby's temperature every 15 to 30 minutes. This is not a replacement for device-based active cooling and is only used until the baby can be transferred to a proper facility.

How the Device Is Used: Step-by-Step

This section describes the clinical procedure followed by healthcare teams in a NICU setting.

Before Starting

• Confirm the baby meets eligibility criteria
• Obtain vascular access (umbilical lines preferred; peripheral IV if not possible)
• Attach pulse oximeter and cardiorespiratory monitor
• Prepare temperature probe (rectal or esophageal) and confirm it is working
• Set up EEG or amplitude-integrated EEG (aEEG) for brain monitoring
• Document start time and initial temperature

Whole-Body Cooling: Step-by-Step Procedure

1. Place the baby (undressed, without blankets) directly on the cooling blanket or mattress.
2. Insert the temperature probe (rectal or esophageal) to continuously monitor core body temperature.
3. Connect the probe to the cooling device. The machine will automatically regulate blanket temperature to reach and hold the target of 33 to 34 degrees Celsius.
4. Cover the baby with only a light sheet if needed for dignity; no warming blankets.
5. Start continuous cardiac monitoring, pulse oximetry, and blood pressure monitoring.
6. Begin or continue EEG monitoring for seizure detection.
7. Monitor and document temperature every 30 minutes, or as per device settings.
8. Check blood glucose, electrolytes, and blood gases at regular intervals as prescribed.
9. Continue cooling for a full 72 hours from the time of start.
10. After 72 hours, begin slow rewarming at a rate of 0.5 degrees Celsius per hour until normal body temperature (36.5 to 37 degrees Celsius) is reached.

Selective Head Cooling: Key Differences

1. Fit the cooling cap snugly around the baby's head, ensuring good contact with the scalp.
2. Set a radiant warmer at a lower level to keep mild body cooling while the head is cooled more intensively.
3. Insert rectal temperature probe; target is 34 to 35 degrees Celsius.
4. Remove the cap every 12 hours to inspect the scalp for skin irritation or injury.
5. After 72 hours, rewarm slowly; passive rewarming continues for 4 hours.

Monitoring During Cooling

Precautions and Possible Complications

Therapeutic hypothermia is a powerful medical treatment that affects nearly every organ system in the body. It must always be performed in a fully equipped NICU with round-the-clock monitoring by trained medical staff.

Known Side Effects and Risks

Precautions to Follow

• Never use warming blankets or heated incubators while cooling is active
• Temperature probe must remain in place and functional at all times
• Check skin and scalp regularly for cold injury
• Fluid intake is usually restricted (40 to 60 ml per kg per day) to avoid brain swelling
• Do not stop cooling abruptly; always rewarm slowly and gradually
• Seizure medications may be needed; phenobarbital is commonly used as first-line treatment
• Feeding decisions are individualized; some babies may receive small trophic feeds during cooling if stable
• All medications given during cooling may have altered effectiveness; dosing may need adjustment

Keeping the Device Safe and in Good Working Order

Before Each Use

• Inspect the cooling blanket or cap for any cracks, leaks, or damage
• Confirm the water reservoir is filled with distilled water (as per manufacturer's instructions)
• Check that all alarms are active and functioning
• Verify the temperature probe is calibrated and reading correctly
• Confirm power supply and backup options are operational

During Use

• Do not place any object on top of the cooling blanket that could compress it
• Keep all tubes and connections secure and unkinked
• Respond to all device alarms promptly; do not silence alarms without identifying the cause
• Document temperature readings from the device at regular intervals
• Never leave the baby unattended while connected to the device

After Each Use

• Clean and disinfect the blanket, mattress, and all reusable components per manufacturer guidelines
• Drain and flush the water circuit if recommended
• Store in a clean, dry location, away from direct sunlight or extreme temperatures
• Log all maintenance in the device service record
• Schedule regular biomedical engineering checks and calibration

Adjunct Monitoring and Supportive Care

Cooling therapy does not work alone. It is always combined with full NICU supportive care, including:

• EEG monitoring: Detects seizures, which are common in HIE but may not always be visible clinically
• MRI brain scan: Typically performed after cooling and rewarming to assess the extent of brain injury
• Near-Infrared Spectroscopy (NIRS): Used in some centers to monitor brain oxygen levels during cooling
• Cranial ultrasound: Done early to check for structural brain abnormalities
• Pain and comfort management: Babies may experience discomfort; appropriate sedation and pain relief are provided
• Nutritional support: Intravenous nutrition is given; enteral feeds are started carefully and only when appropriate

Long-term neurodevelopmental follow-up is an essential part of care for all babies who receive cooling therapy. Regular assessments are needed to identify and address any developmental delays or disabilities.

Frequently Asked Questions