Selective head cooling involves cooling the head while providing radiant warmth to the remainder of the body and allows the brain to be cooler than the rest of the body.  This is accomplished by maintaining the radiant warmer output at 100% and adjusting the cap temperature to achieve the target rectal temperature of 34.5°C ± 0.5° for the 72 hour cooling period.

Standard Criteria for Head Cooling:

The infant should be at least 36 weeks GA, ≥1800 grams, and less than 6 hours old with:

• History compatible with HIE: Apgars <5 at 10 min, pH <7, resuscitation at 10 min, base deficit ≥16 (Note: Should meet ONE of these)
• Physical exam compatible with HIE: lethargy, hypotonia, seizures, coma, weak suck (Note: Should meet ONE of these as well)
• An EEG will be done at time of admission

Starting Head Cooling:

Keep the radiant warmer off while the infant is being assessed for cooling and setting up the Olympic Cool-cap system.

Disposable items from service center:    

• #86126 small cap set (HC <32cm,  weight 1.8-2.5kg)
• #86127 medium cap set (HC 32-37cm,  weight 2.5-4kg)
• #86128 large cap set (HC >37cm,  weight >4kg)
• #86130 box of temperature probes (rectal, scalp, and skin) and sensor covers
• EEG needle electrodes- non chargeable
• 1000ml sterile water inhalation bag (same bag RT uses for vents)

Temperature probes:

•  Rectal temperature probe – Mark rectal temp probe at 5 cm, lubricate, and insert tube to mark, secure with tape.  Check placement of rectal probe prn or if rectal temp changes.  If probe comes out, clean, lubricate, and replace.

• Scalp- place temperature probe plug into sensor to proceed (must be placed into sensor even though not placed on baby, no longer using scalp temp probe over fontanel) Place cooling plastic cap over head, open to the face, not past the hairline, centered with the cutouts over the ears, then place the blue and silver caps over the infant’s head with the silver cap not to extend past the chin, make sure the strap is not stretched too tight under the chin.

• Radiant warmer and cooling machine skin temperature probes – need to be placed over the liver area with reflector probe covers.

General baby care: Keep the bed flat with the infant horizontal, no diaper on infant to allow maximum body exposure to the radiant warmer (can use chux, urine bag, or catheter), do not swaddle in snuggly or blanket rolls, do not blow or circulate air over infant and no enteral feeds during the cooling and rewarming processes of treatment.  Keep the reflective Plexiglas shield over the infant’s head at the level of the chin/neck, resting evenly and directly on the mattress.  It helps to keep the infant close to the head of the bed so the shield covers the cooling tubing.  Do not block the front or back openings of the heat shield.

Initial cool down: Record baseline vitals and temperatures on the Temperature Flow Sheet (place in MR in progress notes when cooling completed).  With the radiant warmer off, turn on the Cool-cap system with initial cap temperatures of:

• Infant’s < 2.5kg: 12°C to 15°C

• Infant’s 2.5kg – 4kg: 10°C to 12°C

• Infant’s > 4kg: 8°C to 10°C

The cap temperature cannot be set lower than 8°C.

The rectal temperature is controlled by changes to the cap temperature with a temperature goal of 34.5°C rectally.  Changes are made to the cap temp in 0.5° increments or less. Wait up to 45 minutes for the infant’s rectal temperature to respond.  It is important to notice trends.

To adjust the cap temperature:

• Touch Set Cap.  The set cap water temperature window appears.

• Touch ˆ to increase or ˇ to decrease the water temperature.  Each button touch will increase or decrease the desired cap water temp by 0.1°C.  Normal adjustments should be made in increments of 0.5° or less and, preferably, in increments of 0.1°C.  A change of 0.1°C will cause an approximate 0.1°C change in rectal temperature.

• Touch OK to save the new temperature.

When the rectal temperature reaches 35.5°C, turn on the radiant warmer in the SERVO mode.  The initial radiant warmer servo setting should be 37°C.  If the rectal temp is already 35.5°C or lower on admission, the radiant warmer may be turned on to prevent overcompensation.  Once the skin temperature stabilizes, regularly adjust the servo setting to approximately 0.5°C above the skin temperature This maintains the radiant warmer output at approximately 100% as the infant’s temperature changes.  Never set the radiant warmer control servo temp > 37.5°C. to prevent overheating the infant.  Skin temp can be adjusted for small infants (<2.5 kg): 37 – 37.5°C, average infants (2.5-4kg): 36-37 ° C and large infants (>4kg): 35 - 36°C. While it is acceptable for the radiant warmer output to occasionally drop to 70% to 80% for short periods of time, the radiant warmer should be adjusted to remain at 100% output most of the time. 

DO NOT USE THE RADIANT WARMER IN THE MANUAL MODE as it will make the infant’s temperature less stable.

Controlling the radiant warmer during cooling maintenance:

• The goal is to maintain a rectal temperature of 34.5°C ± 0.5° with the radiant warmer at 100% on servo control and the cap water temperature as low as possible.  Make adjustments to the rectal temperature with changes to the cap temperature.  Keep the radiant warmer adjusted to provide 100% output without alarms.

Pausing cooling treatment for scalp checks:

• During the cooling treatment, check the integrity of the scalp at least every 12 hours.  The system will prompt for these scalp checks every 12 hours.  It is normal to see an impression of the water cap on the scalp.  Check for redness, bruising, and other discoloration.  Pause cooling treatment during scalp checks.  Whenever possible, limit periods of cap removal to 30 minutes or less.  To avoid disruption of stable cap temperature settings while removing the cap for short term checks, always Touch pause before removing the caps when cooling treatment is in process. 

To pause the cooling treatment:

• Touch PAUSE

• If baby is remaining in bed with cap off and paused for EEG or ultrasound be sure to turn down radiant warmer, try to maintain rectal temperature in target range

• Remove the heat shield

• Remove the complete cap set from the infant’s head, then perform the medical procedures and scalp checks. (If the infant needs to leave the floor, turn off the radiant warmer, unplug the temperature probes from the temperature sensor module, and leave the caps and module with the cooling machine.  When the infant returns, plug the temperature sensors in, turn the radiant warmer back on and continue with the next step)

• Place the complete cap set back on the infant’s head

• Place the heat shield

• Touch RESUME to continue the treatment, if resume is not pressed within 10 minutes to continue cooling treatment, the system will alarm.  If additional time is required, touch OK.

Rewarm Procedure:

During the rewarm procedure, the goal is to raise the infant’s rectal temperature 0.5°C per hour in 0.2°C and 0.3°C increments every 30 minutes.  This procedure may take up to 4 hours if starting at a rectal temperature of 34.5°C - 35°C.  Larger infant’s may require less heat to rewarm or may rewarm faster than 0.5°C per hour, despite the radiant warmer setting.  Closely monitor these infants.  Regularly check the infant’s rectal temperature between the 30 minute servo adjustments.

To rewarm the infant:

• A message box displays when the 72-hour cooling treatment is complete.  TOUCH OK to access the rewarm wizard. Touching DONE will confirm the task as complete and display the next task.

• Remove the heat shield and set aside for cleaning

• Remove the 3 caps: insulating, water retainer, and water cap. Open the Velcro chin strap, and then lift all 3 caps, with the tubing, off the infant’s head.  Discard the blue water cap retainer and silver insulating cap.  Keep the water cap and cap connector tubes connected to the system; these are required for the shutdown procedure.

• Leave the temperature sensors in place; the system will continue to monitor the infant’s temperatures during the 4 hour rewarm period.

• Adjust the radiant warmer servo temperature to approximately 0.3°C above the rectal temperature (or 35°C, lowest Giraffe bed will go, if increasing the temp more than 0.3°C, adjust or skip changing servo temp at the first 30 minute prompt)

• Confirm the tasks as complete.  The system stops circulating and cooling water.  TOUCH REWARM to begin the rewarm period.

• During the 4 hour rewarm period, the system prompts for adjustment of the radiant warmer servo setting 0.2°-0.3°C every 30 minutes.  The system will automatically stop when the 4 hour rewarm period is complete.

• The Cool-cap system uses a 4 hour rewarm period, to shorten this period, touch PATIENT, and then touch SHUTDOWN to stop the rewarm period.

• After the 4 hour rewarm period is complete, the system can be shutdown.  TOUCH OK to access the shutdown wizard.  Follow the prompts on the screen

Ending the cooling treatment early:

If a medical treatment requires that cooling treatment be stopped prematurely, rewarming is recommended.

• TOUCH PATIENT, then touch SHUTDOWN
• Touch REWARM and follow the on-screen instructions to rewarm the infant.
• Touch SHUTDOWN and follow the on-screen instructions to bypass rewarming and shut down the system.
• Touch POWER DOWN to bypass both the rewarm and shutdown wizards and return to the start screen.

Off-Line Rewarming:

If it is necessary to rewarm the infant without access to a Cool-cap system, use the following procedure to rewarm the infant to a rectal temperature of 36.5°C.

• Remove the heat shield
• Remove the 3 caps, open the Velcro chin strap, and then lift all 3 caps with the tubing, off the infant’s head.
• Discard the blue water cap retainer and silver insulating cap, keep the water cap and cap connector tubes connected to the system for the shutdown procedure. 
• Remove the rectal and skin temperature sensors, replace servo temp probe over liver area
• Insert Philips rectal probe and connect to Philips monitor
• Adjust the radiant warmer servo temperature approximately 0.3°C above the infant’s rectal temperature, or 35°C
• After 30 minutes from the initial servo temperature change, increase the radiant warmer servo temperature by 0.2°C, adjust if first increase > 0.3°C, record the time, rectal temp, and radiant warmer servo setting.
• After 30 minutes, increase the radiant warmer servo temperature by 0.3°C; record the time, rectal temperature, and radiant warmer servo setting.
• Continue to repeat these 2 steps until the infant’s rectal temperature reaches 36.5°C.  Do not set the radiant warmer servo temperature > 37.5°C
• If rewarm was in progress, alternate increasing the radiant warmer servo temperature in 0.2°C and 0.3°C increments.

PRECAUTIONS AND WARNINGS

Cooling:

• Hypothermia causes edema and can cause hard edema called SCLEREMA.  Notify MD if infant develops firm edema.

• Hypothermia can inhibit the metabolism and clearance of many anticonvulsants (including phenobarbitone, phenytoin, Lidocaine, and the benzodiazepines) potentially prolonging their half-lives.  Monitor blood levels.

• Hypothermia inhibits antimicrobial activity, it is important to take appropriate cultures and initiate antibiotic treatment even in infants with apparent HIE since the diagnosis can occasionally be confounded by peripartum sepsis.

• Hypothermia has anticoagulant effects.

• At very low temperatures (30°-32°C) hypothermia may increase PPHN

• If an infant is markedly overcooled (~32°C) they may reduce their peripheral circulation in an attempt to conserve heat.  This will reduce the effectiveness of the radiant warmer, thus increasing the problem.  Should this occur, remove the cap and carefully rewarm the infant <0.5°C per hour until the infant is within the target range.  Then resume cooling using the previous or a slightly higher cap setting.

• Hypothermia is known to increase oxygen consumption; therefore some infants may show a small increase in their oxygen requirement.

• Hypothermia may produce prolongation of the QT interval in infants with bradycardia but should normalize after cooling.  Be cautious with other treatments that may further prolong the QT interval (drugs and electrolytes).

• Full term infants with a birth weight < 2.5kg and/or infants with cardiac compromise requiring inotrope support may require a higher cap temperature during the initial cool down and should be closely monitored.  Make temperature adjustments early to avoid over- shooting.

• Treatment of infants < 1.8kg is contraindicated. 

Changes in Temperature:

• Seizures have unpredictable effects.  They usually cause an increase in temperature, but have also been known to decrease temperature.

• Anticonvulsants are likely to lower the rectal temperature

• Core temperature will increase in infants who are upset, jittery, or shivering.

• Core temperature will decrease in infants who are quiet and sleeping.

• Correct all blood gases and pH values for core temperature.

• If the rectal temperature is too high and cap temperature will not reach 8°C, it may help to lower the room temperature by 1°C

Radiant Warmer:

• DO NOT USE THE RADIANT WARMER IN THE MANUAL MODE

• Do not set the radiant warmer servo temperature above 37.5°C to prevent overheating infant.

• The infant’s rectal temperature takes approximately 45 minutes to stabilize after the cap temperature has been adjusted

Rewarming:

• During rewarm, regularly check the infant’s rectal temperature between the 30-minute servo adjustments.

• Active rewarming should not exceed 0.5°C per hour.

• Larger infants may require less heat to rewarm or may rewarm faster than 0.5°C per hour

• Small, full term infants weighing < 2.5kg may require special attention during rewarming.  Watch carefully for cardiovascular instability.

• Ensure that the infant does not rewarm at more than 0.5°C per hour when re-exposed to the full force of the radiant warmer.  Rewarming too quickly can cause vasodilation and hypotension in an unstable infant.