When did clinical enthusiasm for therapeutic hypothermia after cardiac arrest begin?
Two similar studies in the early 2000’s kicked off clinical enthusiasm for therapeutic hypothermia after cardiac arrest. The Bernard trial was a small, quasi-randomized trial with substantial methodological limitations (explored further here by Justin Morgenstern). The HACA trial was a larger RCT that really got the party started.
When did hypothermia first appear?
3. History of hypothermia. All three forms of hypothermia appear to have been recognised since ancient times. In 492 BC Mardonios, a Persian general, was sailing against the Greeks when he encountered bad weather, losing about 300 ships and 20,000 men.
What is hypothermia therapy used for?
Therapeutic Uses Hypothermia treatment can help provide neuroprotection in cases of anoxic brain injury and global brain ischemia, hence its application in cardiac arrest patients and neonatal hypoxic-ischemic encephalopathy1, 4.
Does therapeutic hypothermia improve neurological recovery after global ischemia?
Introduction Therapeutic Hypothermia (TH) improves neurological recovery and reduces mortality after global ischemia, such as in patients with cardiac arrest1-3, and in infants with moderate or severe hypoxic-ischemic encephalopathy4.
What is therapeutic hypothermia?
How long does hypothermia last?
What are the two methods of induced hypothermia?
Does cooling the skin reduce heat exchange?
Is hypothermia a neuroprotective effect?
See more
About this website
When was therapeutic hypothermia first used?
The first clinical trial of hypothermia in the treatment of comatose patients following cardiac arrest was published in 1958, reporting a 50% survival for patients (6 of 12) managed with hypothermia at 33°C compared to 14% (1 of 7) of patients in the normothermic group.
When should targeted temperature management be discontinued?
Recommendation. We suggest that if targeted temperature management is used, duration should be at least 24 hours, as in the 2 largest previous RCTs (weak recommendation, very low-quality evidence).
Who is eligible for therapeutic hypothermia?
Therapeutic Hypothermia (TH) shall be initiated on all adult cardiac arrest patients with return of spontaneous circulation (ROSC) that fit the inclusion criteria, and does not have any of the following: eye opening to painful stimuli, pre-existing coma, traumatic arrest (either penetrating or blunt), body temperature ...
When do you initiate targeted temperature management?
Targeted temperature management should be started as soon as possible. The goal temperature should be reached before 8 hours. Targeted temperature management remains partially effective even when initiated as long as 6 hours after collapse.
When is TTM discontinued?
Potassium administration should be stopped once rewarming begins. Elevated serum glucose level is deleterious to the injured brain.
Is TTM still recommended?
The use of targeted temperature management (TTM) has been recommended for two decades in the management of patients after cardiac arrest; however, the quality of evidence behind this recommendation is moderate to low and refers only to out-of-hospital cardiac arrest (OHCA) [1,2,3,4]. Recently, Dankiewicz et al.
What is Arctic Sun protocol?
The Arctic Sun has adhesive gel pads which stick to a patient's body, and cover only a portion of a patient's body to leave most of the body free for augmenting medical procedures. The device operates under negative pressure and circulates water through the adhesive pads at a temperature between 4–42 °C (39–108 °F).
How successful is therapeutic hypothermia?
In the overall propensity score–matched cohort, 417 patients treated with therapeutic hypothermia (27.4%) survived to hospital discharge, as compared with 1084 non–hypothermia-treated patients (29.2%).
What is code ice in hospital?
Code Ice: Therapeutic Hypothermia (TH) Post-Cardiac Arrest.
When is induced hypothermia indicated?
Indications for hypothermia induction include cardiac arrest and neonatal asphyxia. The two general methods of induced hypothermia are either surface cooling or endovascular cooling. Hypothermia should be induced as early as possible to achieve maximum neuroprotection and edema blocking effect.
What is an absolute contraindication to targeted temperature management or therapeutic hypothermia?
Further, they recommend selecting and maintaining a constant temperature between 32 degrees C and 36 degrees C during TTM. Absolute contraindications to TTM are an awake and responsive patient, DNR, active non-compressible bleeding and the need for immediate surgery.
Therapeutic Hypothermia Protocol FlowChart Chart
o o Phase 3-Re-Warm- Begins once patient has been at goal temperature range of 32-34ᵒC for 24 hours.(Goal is to warm patient to normal temperature over 17-20 hours. o Continue Sedation, Opioid and Paralytic through this phase.
ADULT THERAPEUTIC HYPOTHERMIA PROTOCOL FOLLOWING CARDIAC ARREST
e. Apply Arctic Sun pads to body and use the automatic mode on the Arctic Sun cooling machine. Connect pads to hose. 1) Set the desired target temperature to 330 C, Press Automatic, and begin cooling.
Therapeutic Hypothermia - What You Need to Know
Therapeutic Hypothermia. Medically reviewed by Drugs.com. Last updated on Jun 6, 2022. Care notes; Español; Overview; Risks; What is therapeutic hypothermia? Therapeutic hypothermia is a procedure used to cool a person's body to a temperature that is lower than normal.
Therapeutic Hypothermia After Cardiac Arrest | Circulation
J.P. Nolan. From the *Resuscitation Council of Southern Africa (RCSA), †American Heart Association (AHA), ‡European Resuscitation Council (ERC), §Australia and New Zealand Council on Resuscitation (ANZCOR), ∥International Liaison Committee on Resuscitation (ILCOR), ¶Japanese Resuscitation Council (JRC), #Latin American Resuscitation Council (CLAR), and **Heart and Stroke Foundation of ...
How does hypothermia affect hemodynamics?
At the initiation of TH, tachycardia and hypertension may occur as a result of cutaneous vasoconstriction and shivering as the patient attempts to conserve heat. Once patients begin to cool, bradycardia is the most common arrhythmia, together with PR prolongation, sinus bradycardia, and even junctional or ventricular escape rhythms. Bradycardia should be treated only if it is associated with hypotension. Hypothermia also prolongs the QT interval, although there are no data to suggest that it increases the risk of torsade de pointes.
How long does it take for a rewarming to start?
Rewarming. Rewarming begins 12 to 24 hours after the initiation of cooling. In our institution, we begin after 24 hours, although other institutions begin 24 hours after the target temperature is achieved. The greatest risks during rewarming are hypotension, hyperkalemia, and hypoglycemia.
What temperature should a comatose patient be cooled to?
Comatose (ie, lack of meaningful response to verbal commands) adult patients with ROSC after out-of-hospital VF cardiac arrest should be cooled to 32°C–34°C (89.6°F–93.2°F) for 12 to 24 h ( Class I; Level of Evidence: B ). Induced hypothermia also may be considered for comatose adult patients with ROSC after in-hospital cardiac arrest of any initial rhythm or after out-of-hospital cardiac arrest with an initial rhythm of pulseless electric activity or asystole ( Class IIb; Level of Evidence: B ).Active rewarming should be avoided in comatose patients who spontaneously develop a mild degree of hypothermia (>32°C [89.6°F]) after resuscitation from cardiac arrest during the first 48 h after ROSC ( Class III; Level of Evidence: C ).
What temperature should a patient be at to avoid shivering?
Once a patient achieves the target temperature of 32°C to 34°C, shivering is less common. Nonpharmacological techniques that raise cutaneous temperatures such as wrapping the face, hands, and feet with warm blankets or even placing a warming blanket over the torso are effective at preventing shivering.
What was the purpose of therapeutic hypothermia in the 1970s?
18,19 In the 1970s therapeutic hypothermia was used to reduce secondary brain injury in children with severe anoxic/ischemic insults.
What temperature should hypothermia be induction?
Induction of moderate hypothermia (28°C to 32°C) before cardiac arrest has been used successfully since the 1950s to protect the brain against the global ischemia that occurs during some open-heart surgeries. Successful use of therapeutic hypothermia after cardiac arrest in humans was also described in the late 1950s 1–3 but was subsequently abandoned because of uncertain benefit and difficulties with its use. 4 Since then, induction of hypothermia after return of spontaneous circulation (ROSC) has been associated with improved functional recovery and reduced cerebral histological deficits in various animal models of cardiac arrest. 5–8 Additional promising preliminary human studies have been completed. 9–16 At the time of publication of the Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care, the evidence was insufficient to recommend use of therapeutic hypothermia after resuscitation from cardiac arrest. 17
How long should you cool a cardiac arrest patient?
Unconscious adult patients with spontaneous circulation after out-of-hospital cardiac arrest should be cooled to 32°C to 34°C for 12 to 24 hours when the initial rhythm was ventricular fibrillation (VF). Such cooling may also be beneficial for other rhythms or in-hospital cardiac arrest.
How long should a comatose patient be ventilated?
Although supporting data are limited, many critical care clinicians routinely sedate and ventilate the lungs of comatose survivors of cardiac arrest for at least 12 to 24 hours; thus, application of therapeutic hypothermia over this period would be simple.
Can VF survivors get hypothermia?
Although survivors of VF cardiac arrest have the most to gain from therapeutic hypothermia, some level 4 evidence suggests that survivors from out-of-hospital cardiac arrest of other causes may also benefit. 9 Further study is required.
Can hypothermia be extended after cardiac arrest?
One controversial issue is whether findings from animal experiments and published clinical studies are enough to extend the use of therapeutic mild hypothermia to patients who remain comatose after cardiac arrest from any rhythm, after in-hospital cardiac arrest, and after cardiac arrest in children.
Is hypothermia a good evidence?
There seems to be good evidence (Level 1 [see Appendix ]) to recommend the use of induced mild hypothermia in comatose survivors of out-of-hospital cardiac arrest caused by VF. Selection criteria for treatment were narrowly defined in the best evidence used and thus should be considered carefully when deciding to treat.
What is therapeutic hypothermia?
Therapeutic Hypothermia (TH) improves neurological recovery and reduces mortality after global ischemia, such as in patients with cardiac arrest1-3, and in infants with moderate or severe hypoxic-ischemic encephalopathy4.
How long does hypothermia last?
Some reports suggest that to reduce cerebral edema, hypothermia duration may be needed for 48 to 72 hours after symptom onset32. Longer duration of hypothermia treatment, however, was associated with more adverse effects suggesting treatment should be limited to 24 hours49.
What are the two methods of induced hypothermia?
In general, two methods of induced hypothermia are used currently: surface cooling and endovascular cooling. Surface cooling methods include convective air blankets, water mattresses, alcohol bathing, cooling jackets, and ice packing. Surface cooling techniques have been used for many years in the treatment of fever.
Does cooling the skin reduce heat exchange?
Cooling of the skin surface induc es vasoconstriction and reduces heat exchange in cooled patients; vasoconstriction reduces temperature control, which has lead to target temperature overshoot and lack of control during re-warming16, 20.
Is hypothermia a neuroprotective effect?
Therapeutic Hypothermia has proven neuroprotective effects in global cerebral ischemia. Indications for hypothermia induction include cardiac arrest and neonatal asphyxia. The two general methods of induced hypothermia are either surface cooling or endovascular cooling. Hypothermia should be induced as early as possible to achieve maximum ...
Pharmacology in ACLS Guidelines & Cardiac Arrhythmias
Atropine for Asystole : not recommended in asystole and PEA anymore, not due to negative studies, but rather to the realization that the evidence was always weak and therefore shouldn’t be considered positive
Therapeutic Hypothermia in the ACLS Guidelines
Therapeutic hypothermia (TH) – a good resource: www.NYChypothermia.org
About the Author: Anton Helman
Dr. Anton Helman is an Emergency Physician at North York General in Toronto. He is an Assistant Professor at the University of Toronto, Division of Emergency Medicine and the Education Innovation Lead at the Schwartz-Reisman Emergency Medicine Instititute. He is the founder, editor-in-chief and host of Emergency Medicine Cases.
What was the Bernard trial?
The Bernard trial was a small, quasi-randomized trial with substantial methodological limitations (explored further here by Justin Morgenstern). The HACA trial was a larger RCT that really got the party started.
Does hypothermia slow down inflammation?
Hypothermia will slow down inflammation, but it will also slow down anti-inflammatory pathways. Hypothermia will reduce intracranial pressure, but it may also reduce blood pressure and cerebral perfusion pressure.
Is hypothermia beneficial after cardiac arrest?
Therefore, hypothermia will affect every chemical pathway. As such, hypothermia is an incredibly blunt tool.
Is hypothermia a blunt tool?
As such, hypothermia is an incredibly blunt tool. It’s hard to think of any other medical intervention with such an infinite range of consequences. There is no tissue, nor cell, nor extracellular space which will escape being altered somehow by hypothermia.
What is therapeutic hypothermia?
Therapeutic Hypothermia (TH) improves neurological recovery and reduces mortality after global ischemia, such as in patients with cardiac arrest1-3, and in infants with moderate or severe hypoxic-ischemic encephalopathy4.
How long does hypothermia last?
Some reports suggest that to reduce cerebral edema, hypothermia duration may be needed for 48 to 72 hours after symptom onset32. Longer duration of hypothermia treatment, however, was associated with more adverse effects suggesting treatment should be limited to 24 hours49.
What are the two methods of induced hypothermia?
In general, two methods of induced hypothermia are used currently: surface cooling and endovascular cooling. Surface cooling methods include convective air blankets, water mattresses, alcohol bathing, cooling jackets, and ice packing. Surface cooling techniques have been used for many years in the treatment of fever.
Does cooling the skin reduce heat exchange?
Cooling of the skin surface induc es vasoconstriction and reduces heat exchange in cooled patients; vasoconstriction reduces temperature control, which has lead to target temperature overshoot and lack of control during re-warming16, 20.
Is hypothermia a neuroprotective effect?
Therapeutic Hypothermia has proven neuroprotective effects in global cerebral ischemia. Indications for hypothermia induction include cardiac arrest and neonatal asphyxia. The two general methods of induced hypothermia are either surface cooling or endovascular cooling. Hypothermia should be induced as early as possible to achieve maximum ...
Indications For Use
- Cardiac Arrest, post-resuscitation
In 2003, the American Heart Association (AHA) included hypothermia into its guidelines for cardiopulmonary resuscitation and emergency cardiovascular care. In the AHA 2005 guidelines, it is stated that “unconscious adult patients with return of spontaneous circulation after out-of-hos… - Neonatal Encephalopathy
In May 2005, The National Institute of Child Health and Human Development (NICHD) convened a panel of experts, whom weighed the use of therapeutic hypothermia in perinatal hypoxic-ischemic encephalopathy. The panel concluded that such treatment can potential decrease neurological …
Possible Future Indications
- Traumatic Brain Injury
Traumatic Brain Injury (TBI) is any assault on the brain that disrupts neurological activity. While patients may remain stable after the primary insult, progressing secondary mechanisms can lead to neurological deterioration (Park, 2008). Hypothermic medicine may be a possible future indic… - Spinal Cord Injury
In the United States, Spinal Cord Injury (SCI) affects over 11,000 people per year, resulting in severe neurological disabilities. Like TBI, much of the research attempting to develop treatment for SCI is looking at reducing secondary injuries. (See “How Therapeutic Hypothermia Works”.) T…
How Does Therapeutic Hypothermia Work?
- While the exact mechanism for how hypothermic treatment works to improve patient outcome is still debatable, it is likely being produced through various methods. This is probably in contrast to most medications that only function through a singular method of action. (Dietrch, 2008) Proposed methods include the decrease of cerebral edema and swelling after a head injury. (Yo…
Different Methods to Induce Therapeutic Hypothermia
- Various methods exist with which to administer mild hypothermia. In medical literature, no truly superior method of therapeutic hypothermia has been established in regards to outcome.() The simplest method is surface cooling, where a device is placed along the skin to diffuse heat away from the periphery. Such techniques include placing ice packs typically to strategic locations su…
Adverse Risks of Therapeutic Hypothermia
- In some studies, Therapeutic Hypothermia has had the adverse problems include discomfort, excessive shivering (buchheit, 2009) and hypotension (Clifton, 2009). These issues can be managed with medications; for instance shivering can be managed with a benzodiazepine. However the inclusion of further medication carries with it a new set of concerns and possible ri…
References
- Adams F. The Genuine works of Hippocrates. Williams and Wilkins, Baltimore, MD. 1939
- Koran ZE. Therapeutic Hypothermia in the post resuscitation Patient: The Development and Implementation of an Evidence-Based Protocol in the Emergency Department.Advanced Emergency Nursing Journal...
- Fay T. (1940) Observations on Prolonged Human refrigeration.New York State Journal of Me…
- Adams F. The Genuine works of Hippocrates. Williams and Wilkins, Baltimore, MD. 1939
- Koran ZE. Therapeutic Hypothermia in the post resuscitation Patient: The Development and Implementation of an Evidence-Based Protocol in the Emergency Department.Advanced Emergency Nursing Journal...
- Fay T. (1940) Observations on Prolonged Human refrigeration.New York State Journal of Medicine. 40: 1351-1354
- American Heart Association (2006). AHA/ACC Guidelines for Secondary Prevention for Patients With Coronary and Other Atherosclerotic Vascular Disease: 2006 Update: Endorse by the National Heat, Lung...
Introduction
- Induction of moderate hypothermia (28°C to 32°C) before cardiac arrest has been used successfully since the 1950s to protect the brain against the global ischemia that occurs during some open-heart surgeries. Successful use of therapeutic hypothermia after cardiac arrest in humans was also described in the late 1950s1–3 but was subsequently abandon...
Clinical Studies
- In 2002 the results of 2 prospective randomized trials were published that compared mild hypothermia with normothermia in comatose survivors of out-of-hospital cardiac arrest.18,19 One study was undertaken in 9 centers in 5 European countries19; the other was conducted in 4 hospitals in Melbourne, Australia.18 The criteria for entry into these trials were similar: ROSC, pa…
Mechanisms of Action
- There are several possible mechanisms by which mild hypothermia might improve neurological outcome when used after reperfusion. In the normal brain, hypothermia reduces the cerebral metabolic rate for oxygen (CMRO2) by 6% for every 1°C reduction in brain temperature >28°C.21 Some of this effect is due to reduced normal electrical activity,21 however, and after cardiac arr…
Discussion
- Selection of Patients
There seems to be good evidence (Level 1 [see Appendix]) to recommend the use of induced mild hypothermia in comatose survivors of out-of-hospital cardiac arrest caused by VF. Selection criteria for treatment were narrowly defined in the best evidence used and thus should be consid… - Timing of Cooling
Cooling should probably be initiated as soon as possible after ROSC but appears to be successful even if delayed (eg, 4 to 6 hours). In the European study, the interval between ROSC and attainment of a core temperature of 32°C to 34°C had an interquartile range of 4 to 16 hours.19 …
Use of Therapeutic Hypothermia in Children
- There is currently insufficient evidence to make a recommendation on the use of therapeutic hypothermia in children resuscitated from cardiac arrest. The European and Australian clinical trials excluded children and cardiac arrests of noncardiac etiology (eg, respiratory failure or shock), which are typical of those in children.18,19 In the 1970s therapeutic hypothermia was us…
Summary: Ilcor Recommendations
- On the basis of the published evidence to date, the ILCOR ALS Task Force has made the following recommendations: 1. Unconscious adult patients with spontaneous circulation after out-of-hospital cardiac arrest should be cooled to 32°C to 34°C for 12 to 24 hours when the initial rhythm was VF. 2. Such cooling may also be beneficial for other rhythms or in-hospital cardiac arrest.