For three years, I worked as part of a rapid response team at a hospital. The responsibility of this team was to respond to any critical patient situations, including patients coding. A majority of the time, our calls were to patients after sudden cardiac arrest and where was needed CPR. In a handful of those patients, after successful CPR, the hypoxia, or lack of oxygen to the brain, causes them to fall comatose.
Cardia arrest is one of the biggest causes of death here in America and sadly for patients who do fall comatose, only about 20% wake with minimal neurological deficits (Nolan et. Al., 2003). Cardiac arrest causes a lack of blood flow, ischemia, to the brain and with the lack of oxygen being delivered, the cells began to die and cause for major neurological deficits for patients upon waking.
In the 1950's the idea of using induced hypothermia in comatose cardiac arrest patients, to prevent neurological deficits was introduced. Sadly, the idea was abandoned due to the lack of information known about the side effects of hypothermia and the difficulty to regulate the cooling of the patient. In 2003, the idea of therapeutic hypothermia was reintroduced, advances in technology allowed for better control of inducing hypothermia. A massive study was conducted to identify the affects hypothermia would have on the cardiac patients (Deckard & Ebright, 2017).
In therapeutic hypothermia, the patients' core body temperature is reduced to 32-34 degrees Celsius for about 24-48 hours and then slowly rewarmed to normal body temperature. The study showed significant results presenting the benefits of hypothermia on neurological outcomes for the comatose patients. Therapeutic hypothermia showed to massively reduce the rate of cell death within the brain due to the ischemia (Nolan et. Al., 2003). The number of patients waking with normal neurological function raised to 58% with the induced hypothermia, compared to the original 20%. These findings later lead the American Heart Association to update their protocols for comatose cardiac arrest patients and in 2010, the AHA started to recommend that all hospital implement therapeutic hypothermia as a treatment plan (Deckard & Ebright, 2017).
During my time on the rapid response team, we implemented therapeutic hypothermia in most of our comatose cardiac arrest patients. Our success, with using therapeutic induced hypothermia, matched that of the study with many of our patients waking with minimal, to no neurological deficits.
W., Nolan, J., Morley, P., Hoek, T. V., Hickey, R., & Kloeck, W. (2003, July 08). Therapeutic Hypothermia After Cardiac Arrest: An Advisory Statement by the Advanced Life Support Task Force of the International Liaison Committee on Resuscitation. Retrieved October 07, 2017, from http://circ.ahajournals.org/content/108/1/118
Deckard, M., & Ebright, P. (2017, September 06). Therapeutic hypothermia after cardiac arrest. Retrieved October 07, 2017, from https://www.americannursetoday.com/therapeutic-hypothermia-after-cardiac-arrest-what-why-who-and-how/
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It is very interesting and such a beneficial advantage of understanding, as well as applying, induced hypothermia to decrease the rate of cell death within the brain. Some brain cells, however, begin to die within five minutes of hypoxia (Cerebral, 2017). This does not leave much time to perform CPR, which is why I agree that it is important to induce hypothermia quickly. The study that is mentioned in this article, does take into account the fact that the cardiac events had to be witnessed and resuscitated between 5 and 15 minutes. In those cases is there a correlation with how quickly hypothermia is induced and its success of neurological deficit prevention? I did see in the article you posted that hypothermia will sometimes take 4 hours to reach the proper temperature of 32-34 degrees celsius. I am curious if more rapid induction of hypothermia would lead to even larger success rates.
ReplyDeleteCerebral hypoxia. (n.d.). Retrieved October 09, 2017, from https://medlineplus.gov/ency/article/001435.htm
This concept has actually been used in the field pretty often by accident, so I think it's fascinating that there is an attempt to move it into the hospital setting. Our protocol has always been that for un-witnessed cardiac arrest, we perform CPR and try to bring them back for 20 minutes, but their chances of coming back are low, as they likely didn't receive CPR in time. However, we have exceptions to this protocol in the cases of hypothermia and drowning. When we had a pulseless drowning victim, we would often perform CPR and other interventions for sometimes much longer than 20 minutes, and the medic would not pronounce the patient. That was left to the physician in the hospital, as it was understood that drowning victims and hypothermic patients would have a much higher rate of survival of unwitnessed cardiac arrest. Very interesting!
ReplyDeleteThis is very cool and I personally have seen this used a couple of times before was well. Putting a patient in a suspended state with a decreased body temperature is something that most people would only think would occur in a movie. I have seen multiple patients successfully undergo similar hypothermic measures with significant results. I do remember a time when a patient was placed on the cardiac ICU and an attending and his resident were arguing over the best course of action for the patient. The resident had suggested the use of therapeutic hypothermia and produced the results and multiple publications backing his claims for the patient. Eventually the attending gave into the persistence of the resident and allowed the therapeutic hypothermia to commence. This overall yielded an amazing recovery for the patient and allowed for almost full neurological function to be maintained.
ReplyDeleteIt is amazing how far technology has come when it comes to preserving a patient’s quality of life, despite experiencing traumatic events. I work on the cardiac tower as a CNA and we often have to page a rapid response for our patients if they become unresponsive. From my experience, most patients in this situation have the potential for significant reduction in their motor and sensory skills and perceptions. To have a method to reduce unnecessary symptoms is a huge step in the medical field. However, I wonder what the procedural logistics are of inducing hypothermia. For instance, what would consent look like? What is the optimal time, or even an acceptable time, after a patient’s episode, to induce hypothermia? With the rising obesity epidemic, there is an increase in cardiovascular disease and stroke which occur outside a medical setting. This can lead to a prolonged response time which can have significant consequences. So, at what point does inducing hypothermia become more of a risk than a treatment option for these individuals.
ReplyDeleteIf worse came to worst, and the patient ended up in a vegetative state, there may be some hope. I came across this article that when stimulating the vagus nerve in comatose patients, they showed promising reactions that mirror consciousness.
Cell Press. "After 15 years in a vegetative state, nerve stimulation restores consciousness." ScienceDaily. ScienceDaily, 25 September 2017. .
"Obesity Information." Obesity Information. American Heart Association, 18 Oct. 2016. Web. 14 Oct. 2017.
http://www.heart.org/HEARTORG/HealthyLiving/WeightManagement/Obesity/Obesity-Information_UCM_307908_Article.jsp#.WeGWXWi3w2w
Weintraub, Karen. "Man Partly Wakes From 15-Year Vegetative State-What It Means."National Geographic. National Geographic Society, 25 Sept. 2017. Web. 14 Oct. 2017.
http://news.nationalgeographic.com/2017/09/vegetative-state-vagus-nerve-stimulation-health-science/