Therapeutic Hypothermia: Background
Therapeutic hypothermia has been around for centuries; ancient Egyptians, Greeks, and Romans used it. Hypothermia is any body temperature below 35°C.
Therapeutic Hypothermia (TH) is induced hypothermia and is classified as mild (34 to 35.9°C), moderate (32 to 33.9°C), moderately deep (30.1 to 31.9°C) or deep (less than 30°C). TH is the lowering of temperature in order to act as a general neuroprotectant after injury, and is primarily used to treat four areas of neurological deficit: cardiac arrest, myocardial infarction, stroke, and traumatic brain injury. Future applications may potentially include heat stroke, drug overdose, submersion injuries, fever, sepsis, neonatal encephalopathy, birth asphyxia.
Incidence & Prevalence
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How Soon Should You Cool?
The answer is actually to cool as soon as possible! In fact, in only 3 to 6 minutes after neurologic injury, brain cells will begin to die. Studies have shown that the earlier cooling is initiated, the more likely a positive outcome is to occur. Prehospital cooling is especially important because every five minute delay in hypothermia treatment increases the chance of poor neurological outcome as compared to a good outcome by 3%. In addition, every 1-hour delay increases risk of death by 20%. Early cooling benefits the patient and healthcare system by not only increasing chance of survival, but also by decreasing the potential amount of damage.
Why Do We Cool?
Reducing brain temperature is a key factor in preventing or mitigating secondary or reperfusion damage after cardiac arrest, heart attack, stroke, or traumatic brain injury. But how does cooling the brain help
+ Lowers metabolism which in turn requires less oxygen for cells to stay alive
+ Encourages cell membrane stability during periods of oxygen deprivation
+ Reduces or eliminates free radical production (free radicals are bad and kill brain cells)
+ Reduces the risk of the ischemic injury to brain tissue following a period of insufficient blood flow
+ Helps to reduce reperfusion injury damage caused by oxidative stress when the blood supply is restored.
+ Reduces intracranial pressure (swelling) in the brain, which increased ICP leads to cell injury & death
+ Reduces intermittent fever spikes back to normothermic temperatures (98.6°F, 37.0°C)
+ Mild hypothermia is a temperature drop by a factor of 0.8 to 3°Celsius
+ A similar benefit is produced from anywhere within this 3 degree drop range
Standard of Care
In 2002, two landmark studies published in the New England Journal of Medicine effectively brought TH back into focus. The European study noted “75 of the 136 patients (55%) in the hypothermia group for whom data were available had a favorable neurological outcome.” The Australian study noted “21 of 43 patients (49%) showed good neurological function at discharge.” In 2005, the AHA gave therapeutic hypothermia a Class II recommendation, making it standard of care. In 2010, the AHA revised its protocol and upgraded it to a Class I recommendation. The development of therapeutic hypothermia as treatment has been hailed as the largest advancement in treating neurologic injury in the last 15 years
See a more detailed history of therapeutic hypothermia by clicking here
In 2010, after the change to the AHA recommendation to Class IA, methods such as the infusion of chilled saline and use of ice packs on the groin areas were employed when available. Chilled saline has many potential side effects, including increased risk of infection, hemodilution, coagulopathy, decreased drug interaction, increased blood pressure, and in many cases the use of paralytics is necessary to counteract shivering. Ice packs are considered largely ineffective when used alone, having the ability to only lower the body’s temperature by about a half a degree per hour.
A Solution: The Excel Cryo Cooling System
In response to an unmet need for a product that could induce cooling effectively to the mild therapeutic range, Dr. Aqeel Sandhu developed the Excel Cryo Cooling System. The Excel Cryo Cooling System is an easy to use, 10 second solution to induce cerebral cooling in patients after a cardiac arrest, stroke, or traumatic brain injury. The unique design of the system provides consistent cooling of the brain from incident through to the I.C.U.
The Excel uses the functional design of a standard C-collar incorporated with a front door and cooling element to cool the blood traveling through the carotid triangle, and selectively cool the brain. Its unique focus on the carotids is unmatched by any current method or product, and provides a simple, safe, solution that any first responder in a pre- of in-hospital setting can provide.
See how the Excel compares to previously described methods – click here