A paper by Niklas Nielsen et al titled “Targeted temperature management at 33°C versus 36°C after cardiac arrest”. Published online by The New England Journal of Medicine on November 17, 2013 has brought a lot of attention to the use of therapeutic hypothermia for post-cardiac arrest cares. It stormed through the social media channels. Within days, EMRAP, Emcrit, Life in the Fast Lane, St. Emlyn’s, Intensive Care Network and most other ED/critical care websites and podcasts had devoted time to covering it. It may very well be practice changing in emergency departments and ICUs through throughout the world. Or maybe not. Before we can figure out what “truth” this research study may have uncovered, we will look at the development of therapeutic hypothermia and what the literature has already told us.

Download Episode: ResusReview-Podcast-02-Therapeutic-Hypothermia-History-and-TTM-Trial.mp3

Chapter 1 The Beginning

Ancient societies had long figured out that hypothermia was useful for acute hemorrhage control. But Hippocrates had figured out a way to use the body’s heat production as a diagnosis tool. He would take his patients, and cake them in mud. The areas that dried first were warmer. “In whatever part of the body excess of heat or cold is felt, the disease is there to be discovered.” And once they figured out the diseased are, the proceeded to inflict their “cures” on the patient.

Typhoid fever which had been the plague of Athens in 400 BC and caused the die out of the Jamestown Colony in the early 1600s, led Robert Boyle around 1650 to attempt to cure Typoid by dunking patients in ice-cold brine. While this is likely the first true application of therapeutic hypothermia, it was unfortunately unsuccessful and failed to alter the 30-40% mortality rate of Typhoid. 100 years later James Currie expanded on Boyle’s work to look at the effects of hot, cold, and warm to treat fevers…both by applying it to the surface and having the patients drink it. These innovations did not seem to bring any more success than the ice-cold brine did however. He did find some usefulness from his other work with opium and alcohol for inanition though.

In the early 1800s, hydropaths had become popular though separate from medicine. Osler referred to them as “hermaphrodite practitioners who look upon water as a cure-all”. BUt he realized the hygienic and therapeutic effects of their use of compresses, douches, and baths. Brand, a hydropath from Settin, ended up teach Osler that systematic rigid protocol of cold baths for Typhoid fever did save lives, and Osler implemented this at John Hopkins with success. He published this protocol in an article “The Cold-Bath Treatment of Typhoid Fever” in 1892, and a drop in mortality was seen throughout by physicians everywhere.

During this time, Russian physicians had independently begun using cold for resuscitation. People who suddenly became unresponsive, were covered with snow hoping for return of spontaneous circulation.

Chapter 2 The 1930s and breaking the thermal barrier

This “thermal barrier” was so deeply ingrained into medical techniques at the time that subnormal temperature were to be combated at all cost. All of the clinical thermometers of the time were calibrated down to only 94 F, as the lowest temperature compatible with survival in human being. Below this level, they were confident that human life could not be sustained. Shock cabinets with electrical heating devices or hot water bottles and warm blankets were considered as necessary emergency equipment in every hospital. But this was about to change.

Therapeutic Hypothermia’s father is Dr. Temple Fay. A Neurosurgeon at Temple University. As a medical student one day he was quizzed by his mentor on why tumors were less common in the extremities. He was unable to come up with a reasoned response. This ultimately led him down the path of experimental cancer work. In 1937, he published work on suspending the growth of cancer cells when they were made hypothermic, but their growth would resume normally when normal temperatures were restored.

In a remarkable bench to bedside transition, the next year in 1938, he treated is first cancer patient with hypothermia in an attempt to prevent cancer cells from further multiplying. Chloral hydrate, sodium bromide (both sedatives) were given by rectum the night before. Paraldehyde, another sedative, was given immediately before hypothermia induction. The patient was cooled to 32 deg C for 24 hours, and he was a meticulous record keeper continuously monitoring pulse pressure, Hgb, pH, CO2, urine, blood analysis.

He described it like this.

The First attempt at general refrigeration was made on November 28, 1938, which was welcomed as a cool crisp day in Philadelphia. Cool enough so that when I move other patients out of a small four-bed ward, shut off the heat, closed the door to the hall, and opened the winders, Nature herself supplied the cold air that aided the cracked ice, 150 pounds of which was begged from the hospital kitchen. For many reasons, chiefly because of the prejudice on the part of the nurses, we had not dared submerge the entire patient in a bed of cracked ice. As it was, the Superintendent of the hospital was more concerned about the wet mattresses from the melting ice than the scientific principle. The nurses’ home, interns quarters and many members of the staff of other services, were alive with dubious comment and conjecture regarding the idea of human refri