- Email: [email protected]
Successful treatment of severe heat stroke with selective therapeutic hypothermia using an automated surface cooling device
Resuscitation 84 (2013) e77–e78
Contents lists available at SciVerse ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
Letter to the Editor Successful treatment of severe heat stroke with selective therapeutic hypothermia using an automated surface cooling device夽 Out-of hospital cardiac arrest with ventricular fibrillation (VF) or ventricular tachycardia (VT) is a primary indication for the use of therapeutic hypothermia (TH), which provides some neuroprotection. We devised and applied a selective TH protocol for use in heat stroke. In patients failing to recover consciousness to ‘verbal response’ despite cooling to 39 ◦ C, we adopted a rapid cooling strategy using cold saline intravenous infusion, an automated surface cooling device and selective TH. We report three severe heat stroke cases using this protocol. In all cases, their rectal temperatures were over 40 ◦ C and rapidly decreased to the primary cooling target of 39 ◦ C with automated surface cooling devices and infusion of cold saline within 1 h after presentation. Two of these three cases had persistent coma and did not respond to verbal stimuli. These patients received TH to a target temperature 32–34 ◦ C for 24 h, with deep sedation and analgesics. They both made a full neurological recovery and there were no significant complications associated with TH. The other case recovered to alert mental status after reaching the primary target temperature and therefore did not receive TH. All three cases made a full neurological recovery and were discharged without complication. This report suggests that application of an automated surface cooling device is an effective and feasible method of rapid cooling and selective TH might be a safe and effective treatment for neuroprotection for heat stroke patients. Sir, Immediate cooling is the most important treatment to improve the outcome of heat stroke patients.1 Traditionally, the two main methods are evaporation using fanning or ice water immersion. Evaporation is easy to perform but it has low cooling efficacy.1 Ice water immersion has good cooling efficacy, but it is difficult to perform in a busy emergency department (ED) and is associated with mortality and morbidity.1 Compared to these, an automated surface cooling device has merits including high cooling efficacy, easy usability, safety, and cost effectiveness.2 Therapeutic hypothermia (TH) might be helpful for the protection from further neurological injury in heat stroke patients because the pathophysiology of neurological damage in heat stroke is similar to that seen in post-cardiac arrest patients. TH protects the brain by reducing cerebral metabolism, cerebral edema, reperfusion injury and apoptosis.3 In an animal model, brain cooling attenuated cerebral oxidative stress, systemic inflammation, activated coagulation, and tissue ischemia/injury during heat stroke.4 Hong et al. first reported successful treatment of heat stroke with TH by a noninvasive external cooling system.5
夽 This study was presented at the Panpacific Emergency Medicine Conference 2012.
Fig. 1. The change of rectal temperature according to the time after application of automated surface cooling device.
Based on this evidence, we devised a selective TH protocol using an automated surface-cooling device for heat stroke. If a patient with heat stroke had evidence of central nervous system involvement, we initiated immediate cooling using a combination of cold (4 ◦ C) saline intravenous infusion, cold pack, evaporation with fanning and an automated surface cooling device (Rapr RoundTM body wraps, Gaymar Medi-Therm® , Orchard Park, NY). When the core temperature dropped to 39 ◦ C, we assessed the patient’s conscious level. If the patient had recovered, we maintained normothermia with supportive care. If the patient showed persistent verbal response or less, or had significant neurological symptoms, following informed consent from the patient’s guardian, we induced TH to a target temperature of 32–34 ◦ C using an automated surface cooling device. The patient was sedated with intravenous midazolam, fentanyl and vecuronium. We maintained TH for 24 h and began rewarming over 12 h at a rate of 0.4 ◦ C/h to normothermia and the stopped the sedation. Three heat stroke patients presented to our ED during summer in 2012. We treated them along with this protocol. Two were classical and one was exertional heat stroke. Within 1 h after presentation, core temperature rapidly decreased to 39 ◦ C and within 6 h after presentation, the target temperature of TH was achieved (Fig. 1). One patient was not given TH because he made a full neurological recovery on reaching 39 ◦ C. All patients made a full neurological recovery and there were no complications associated with TH. In our case series, automated surface cooling device was effective, feasible and safe when combined with traditional cooling methods. The selective TH may protect against permanent neurological injury in heat stroke patients with persistent neurologic deficit. A multi-center randomized controlled trial is warranted to determine whether NH is beneficial in heat stroke.
0300-9572/$ – see front matter. Crown Copyright © 2013 Published by Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.resuscitation.2013.02.024
e78
Letter to the Editor / Resuscitation 84 (2013) e77–e78
Conflict of interests The authors have no conflict of interests, especially with the company which develop and sell the automated surface cooling device used in this article. This work was supported by a grant funded by the Medical School of Korea University (Grant number K1220251). References 1. Bouchama A, Dehbi M, Chaves-Carballo E. Cooling and hemodynamic management in heatstroke: practical recommendations. Crit Care 2007;11:R54. 2. Varon J, Marik PE, Einav S. Therapeutic hypothermia: a state-of-the-art emergency medicine perspective. Am J Emerg Med 2012;30:800–10. 3. Neumar RW, Nolan JP, Adrie C, et al. Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A consensus statement from the International Liaison Committee on Resuscitation (American Heart Association, Australian and New Zealand Council on Resuscitation, European Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, and the Resuscitation Council of Southern Africa); the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council. Circulation 2008;118: 2452–83.
4. Hsu SF, Niu KC, Lin CL, Lin MT. Brain cooling causes attenuation of cerebral oxidative stress, systemic inflammation, activated coagulation, and tissue ischemia/injury during heatstroke. Shock 2006;26:210–20. 5. Hong JY, Lai YC, Chang CY, Chang SC, Tang GJ. Successful treatment of severe heatstroke with therapeutic hypothermia by a noninvasive external cooling system. Ann Emerg Med 2012;59:491–3.
Eui Jung Lee Sung-Woo Lee ∗ Jong-Su Park Su-Jin Kim Yun-Sik Hong Department of Emergency Medicine, College of Medicine, Korea University, Seoul, Republic of Korea ∗ Corresponding
author at: Korea University Anam Hospital Emergency Department, 126-1, 5-ga, Anam-dong, Sungbuk-gu, Seoul 136-705, Republic of Korea. E-mail address: [email protected] (S.-W. Lee) 19 February 2013
Contents lists available at SciVerse ScienceDirect
Resuscitation journal homepage: www.elsevier.com/locate/resuscitation
Letter to the Editor Successful treatment of severe heat stroke with selective therapeutic hypothermia using an automated surface cooling device夽 Out-of hospital cardiac arrest with ventricular fibrillation (VF) or ventricular tachycardia (VT) is a primary indication for the use of therapeutic hypothermia (TH), which provides some neuroprotection. We devised and applied a selective TH protocol for use in heat stroke. In patients failing to recover consciousness to ‘verbal response’ despite cooling to 39 ◦ C, we adopted a rapid cooling strategy using cold saline intravenous infusion, an automated surface cooling device and selective TH. We report three severe heat stroke cases using this protocol. In all cases, their rectal temperatures were over 40 ◦ C and rapidly decreased to the primary cooling target of 39 ◦ C with automated surface cooling devices and infusion of cold saline within 1 h after presentation. Two of these three cases had persistent coma and did not respond to verbal stimuli. These patients received TH to a target temperature 32–34 ◦ C for 24 h, with deep sedation and analgesics. They both made a full neurological recovery and there were no significant complications associated with TH. The other case recovered to alert mental status after reaching the primary target temperature and therefore did not receive TH. All three cases made a full neurological recovery and were discharged without complication. This report suggests that application of an automated surface cooling device is an effective and feasible method of rapid cooling and selective TH might be a safe and effective treatment for neuroprotection for heat stroke patients. Sir, Immediate cooling is the most important treatment to improve the outcome of heat stroke patients.1 Traditionally, the two main methods are evaporation using fanning or ice water immersion. Evaporation is easy to perform but it has low cooling efficacy.1 Ice water immersion has good cooling efficacy, but it is difficult to perform in a busy emergency department (ED) and is associated with mortality and morbidity.1 Compared to these, an automated surface cooling device has merits including high cooling efficacy, easy usability, safety, and cost effectiveness.2 Therapeutic hypothermia (TH) might be helpful for the protection from further neurological injury in heat stroke patients because the pathophysiology of neurological damage in heat stroke is similar to that seen in post-cardiac arrest patients. TH protects the brain by reducing cerebral metabolism, cerebral edema, reperfusion injury and apoptosis.3 In an animal model, brain cooling attenuated cerebral oxidative stress, systemic inflammation, activated coagulation, and tissue ischemia/injury during heat stroke.4 Hong et al. first reported successful treatment of heat stroke with TH by a noninvasive external cooling system.5
夽 This study was presented at the Panpacific Emergency Medicine Conference 2012.
Fig. 1. The change of rectal temperature according to the time after application of automated surface cooling device.
Based on this evidence, we devised a selective TH protocol using an automated surface-cooling device for heat stroke. If a patient with heat stroke had evidence of central nervous system involvement, we initiated immediate cooling using a combination of cold (4 ◦ C) saline intravenous infusion, cold pack, evaporation with fanning and an automated surface cooling device (Rapr RoundTM body wraps, Gaymar Medi-Therm® , Orchard Park, NY). When the core temperature dropped to 39 ◦ C, we assessed the patient’s conscious level. If the patient had recovered, we maintained normothermia with supportive care. If the patient showed persistent verbal response or less, or had significant neurological symptoms, following informed consent from the patient’s guardian, we induced TH to a target temperature of 32–34 ◦ C using an automated surface cooling device. The patient was sedated with intravenous midazolam, fentanyl and vecuronium. We maintained TH for 24 h and began rewarming over 12 h at a rate of 0.4 ◦ C/h to normothermia and the stopped the sedation. Three heat stroke patients presented to our ED during summer in 2012. We treated them along with this protocol. Two were classical and one was exertional heat stroke. Within 1 h after presentation, core temperature rapidly decreased to 39 ◦ C and within 6 h after presentation, the target temperature of TH was achieved (Fig. 1). One patient was not given TH because he made a full neurological recovery on reaching 39 ◦ C. All patients made a full neurological recovery and there were no complications associated with TH. In our case series, automated surface cooling device was effective, feasible and safe when combined with traditional cooling methods. The selective TH may protect against permanent neurological injury in heat stroke patients with persistent neurologic deficit. A multi-center randomized controlled trial is warranted to determine whether NH is beneficial in heat stroke.
0300-9572/$ – see front matter. Crown Copyright © 2013 Published by Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.resuscitation.2013.02.024
e78
Letter to the Editor / Resuscitation 84 (2013) e77–e78
Conflict of interests The authors have no conflict of interests, especially with the company which develop and sell the automated surface cooling device used in this article. This work was supported by a grant funded by the Medical School of Korea University (Grant number K1220251). References 1. Bouchama A, Dehbi M, Chaves-Carballo E. Cooling and hemodynamic management in heatstroke: practical recommendations. Crit Care 2007;11:R54. 2. Varon J, Marik PE, Einav S. Therapeutic hypothermia: a state-of-the-art emergency medicine perspective. Am J Emerg Med 2012;30:800–10. 3. Neumar RW, Nolan JP, Adrie C, et al. Post-cardiac arrest syndrome: epidemiology, pathophysiology, treatment, and prognostication. A consensus statement from the International Liaison Committee on Resuscitation (American Heart Association, Australian and New Zealand Council on Resuscitation, European Resuscitation Council, Heart and Stroke Foundation of Canada, InterAmerican Heart Foundation, Resuscitation Council of Asia, and the Resuscitation Council of Southern Africa); the American Heart Association Emergency Cardiovascular Care Committee; the Council on Cardiovascular Surgery and Anesthesia; the Council on Cardiopulmonary, Perioperative, and Critical Care; the Council on Clinical Cardiology; and the Stroke Council. Circulation 2008;118: 2452–83.
4. Hsu SF, Niu KC, Lin CL, Lin MT. Brain cooling causes attenuation of cerebral oxidative stress, systemic inflammation, activated coagulation, and tissue ischemia/injury during heatstroke. Shock 2006;26:210–20. 5. Hong JY, Lai YC, Chang CY, Chang SC, Tang GJ. Successful treatment of severe heatstroke with therapeutic hypothermia by a noninvasive external cooling system. Ann Emerg Med 2012;59:491–3.
Eui Jung Lee Sung-Woo Lee ∗ Jong-Su Park Su-Jin Kim Yun-Sik Hong Department of Emergency Medicine, College of Medicine, Korea University, Seoul, Republic of Korea ∗ Corresponding
author at: Korea University Anam Hospital Emergency Department, 126-1, 5-ga, Anam-dong, Sungbuk-gu, Seoul 136-705, Republic of Korea. E-mail address: [email protected] (S.-W. Lee) 19 February 2013