Clinical paperOut-of-hospital surface cooling to induce mild hypothermia in human cardiac arrest: A feasibility trial☆
Introduction
Sudden cardiac death is a major health concern, with evolving emergency care strategies.1, 2 Mild hypothermia has been one of the few measures that have been shown in several experimental and clinical studies to improve neurological outcome after cardiac arrest.3, 4, 5, 6, 7, 8 Animal data suggest that early induction of hypothermia is crucial in order to obtain its beneficial effect.9, 10, 11, 12 Therefore, the advanced cardiac life support guidelines recommend initiating mild therapeutic hypothermia ‘as soon as possible’.13
In recent years, non-invasive as well as invasive cooling methods for induction of mild hypothermia after resuscitation from cardiac arrest have been investigated.8, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 To clinically translate the results of animal studies9, 10, 11, 12 and to follow the guidelines,30 cooling methods are needed which are feasible, non-invasive, immediately applicable and available in the out-of-hospital setting to emergency medical service (EMS) providers. The efficacy and safety in the out-of-hospital setting of newly designed cooling pads for surface cooling of persons resuscitated after cardiac arrest are evaluated in this preliminary explorative study.
Section snippets
Materials and methods
This study was a collaboration between the Ambulance Service and the Department of Emergency Medicine of the Medical University in Vienna. Data of a sample of consecutive patients treated by the Ambulance Service after out-of-hospital cardiac arrest were collected, and cooling efficacy and safety of the new cooling pads (Emcoolspad®, Emcools, Vienna, Austria) were analysed. Protocols were approved by the local ethics committee, and for all participants the requirement of informed consent was
Results
Eight emergency medical service ambulances were equipped with the cooling pads. From October 2006 to January 2007, the ambulance staff attended 61 out-of-hospital cardiac arrests. ROSC was achieved in 32 (52%) cases, and 15 (25%) fulfilled the inclusion criteria for application of the cooling device. Patients who were excluded numbered three younger than 18 years, three conscious before any cooling, two with Tes <34 °C, two whose cardiac arrest occurred during transport and just before arrival
Discussion
Non-invasive surface cooling with cooling pads was a fast, feasible and safe method in the out-of-hospital setting for early induction of therapeutic hypothermia after non-traumatic cardiac arrest. The median time to reach a target temperature of 33 °C was 70 (55–106) min, which resulted in a cooling rate of 3.3 (2.0–4.0) °C/h. Target temperature was reached 50 (49–82) min after hospital admission. Apart from some minor skin irritation without any permanent damage or scar formation, no adverse
Conclusion
Non-invasive surface cooling with cooling pads in the out-of-hospital setting immediately after resuscitation from cardiac arrest proved feasible, fast and safe. Whether such early cooling improves neurological outcome, as compared with delayed cooling in hospital, needs to be determined in a prospective randomised trial.
Conflict of interest
Wilhelm Behringer is a co-founder and stockholder in Emcools AG.
Acknowledgements
On behalf of the Vienna Hypothermia After Cardiac Arrest (HACA) Study Group, the authors want to thank the participating paramedics and emergency physicians of the Ambulance Service of Vienna and the nurses of the Department of Emergency Medicine for their support of the study.
This project was funded in part by a grant from the Jubiläumsfonds of the Austrian National bank (no. 12121). Emcools AG, Vienna, Austria, provided the cooling device and technical and administrative support, but was not
References (42)
- et al.
The problem of out-of-hospital cardiac-arrest prevalence of sudden death in Europe today
Am J Cardiol
(1999) - et al.
Mild hypothermia induced by a helmet device: a clinical feasibility study
Resuscitation
(2001) - et al.
Clinical trial of induced hypothermia in comatose survivors of out-of-hospital cardiac arrest
Ann Emerg Med
(1997) - et al.
Cold infusions alone are effective for induction of therapeutic hypothermia but do not keep patients cool after cardiac arrest
Resuscitation
(2007) - et al.
Induction of therapeutic hypothermia after cardiac arrest in prehospital patients using ice-cold Ringer's solution: a pilot study
Resuscitation
(2004) - et al.
Feasibility and efficacy of a new non-invasive surface cooling device in post-resuscitation intensive care medicine
Resuscitation
(2007) - et al.
Induced hypothermia using large volume, ice-cold intravenous fluid in comatose survivors of out-of-hospital cardiac arrest: a preliminary report
Resuscitation
(2003) - et al.
Cardiac arrest and cardiopulmonary resuscitation outcome reports: update and simplification of the Utstein templates for resuscitation registries. A statement for healthcare professionals from a task force of the International Liaison Committee on Resuscitation
Resuscitation
(2004) - et al.
Brain ischemia and reperfusion: molecular mechanisms of neuronal injury
J Neurol Sci
(2000) - et al.
Prehospital induction of therapeutic hypothermia during CPR: a pilot study
Resuscitation
(2008)
Feasibility of external cranial cooling during out-of-hospital cardiac arrest
Resuscitation
Cold simple intravenous infusions preceding special endovascular cooling for faster induction of mild hypothermia after cardiac arrest—a feasibility study
Resuscitation
A prospective, multicenter pilot study to evaluate the feasibility and safety of using the CoolGard System and Icy catheter following cardiac arrest
Resuscitation
Out-of-hospital cardiac arrest in the 1990s: a population-based study in the Maastricht area on incidence, characteristics and survival
J Am Coll Cardiol
Mild cerebral hypothermia during and after cardiac arrest improves neurologic outcome in dogs
J Cereb Blood Flow Metab
Improved cerebral resuscitation from cardiac arrest in dogs with mild hypothermia plus blood flow promotion
Stroke
Therapeutic hypothermia after cardiac arrest
Curr Opin Crit Care
Mild therapeutic hypothermia to improve the neurologic outcome after cardiac arrest
N Engl J Med
Treatment of comatose survivors of out-of-hospital cardiac arrest with induced hypothermia
N Engl J Med
Hypothermia for neuroprotection after cardiac arrest: systematic review and individual patient data meta-analysis
Crit Care Med
Delay in cooling negates the beneficial effect of mild resuscitative cerebral hypothermia after cardiac arrest in dogs: a prospective, randomized study
Crit Care Med
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2019, Clinical Neurology and NeurosurgeryPrehospital surface cooling is safe and can reduce time to target temperature after cardiac arrest
2015, ResuscitationCitation Excerpt :The temperature probe was connected to a monitoring device before initiating cooling. Cooling was performed by application of cooling pads29 (EMCOOLS Flex.Pad®, EMCOOLS – Emergency Medical Cooling Systems AG, Pfaffstätten, Austria) on the thorax, back, abdomen and thighs (Fig. 1). Time of cooling start and first Tes measured prior to cooling was documented.
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A Spanish translated version of the summary of this article appears as Appendix in the final online version at doi:10.1016/j.resuscitation.2008.01.005.
- 1
The Vienna Hypothermia After Cardiac Arrest (HACA) Study Group: Jasmin Arrich; Alexander Auer; Kewan Bayegan; Wilhelm Behringer; Andreas Braunisch; Philip Eisenburger; Roman Fleischhackl; Monika Fusek; Oliver Geyer; Christoph Havel; Moritz Haugk; Herbert Heissenberger; Micheal Holzer; Andreas Janata; Alfred Kaff; Andreas Kliegel; Maria-Petra Krenn; Anton N Laggner; Johannes Lahmer; Heidrun Losert; Nina Richling; Eva Riedmüller; Kurt Schafellner.