Background: Prehospital cooling of acute stroke patients would be ideal when associated with minor or no side effects. Therefore, we evaluated a cooling cap for the surface of head and cervical regions in awake volunteers. Methods: 10 healthy volunteers were treated by external cooling for 190 min using a gel-based cooling device. Vital signs, rectal temperature, tympanic temperature, the extent of shivering and individual perception of frostiness and discomfort were measured. Results: All participants (median age 35 years) successfully completed the treatment and experienced only mild to moderate discomfort. No serious adverse events and no shivering were noticed. There was a significant drop in the tympanic temperature to 34.68°C (difference from baseline: 1.7°C, 95% CI: 0.61–2.7°C, p = 0.001), in the rectal temperature to 36.65°C (difference from baseline: 0.65°C, 95% CI: 0.06–1.2°C, p = 0.019) and in the heart rate (difference from baseline: 15 beats/min, 95% CI: 0.63–30 beats/min, p = 0.035). Conclusion: Treatment with the cooling device was well tolerated by all participants. The technique had measurable effects on core body temperature (rectal) and tympanic temperature (may reflect temperature at the external ear and skin rather than intracranial). It can be considered as a simple therapeutic approach to patients with suspected stroke in the prehospital setting.

Keywords:
Hypothermia, Cooling cap, Cooling, Stroke
1.
Kollmar R, Schwab S: Hypothermia in focal ischemia: implications of experiments and experience. J Neurotrauma 2009;26:377–386.
2.
van der Worp HB, Sena ES, Donnan GA, Howells DW, Macleod MR: Hypothermia in animal models of acute ischaemic stroke: a systematic review and meta-analysis. Brain 2007;130:3063–3074.
3.
Cabanas JG, Brice JH, De Maio VJ, Myers B, Hinchey PR: Field-induced therapeutic hypothermia for neuroprotection after out-of hospital cardiac arrest: a systematic review of the literature. J Emerg Med 2011;40:400–409.
4.
Kollmar R, Schellinger PD, Steigleder T, Kohrmann M, Schwab S: Ice-cold saline for the induction of mild hypothermia in patients with acute ischemic stroke: a pilot study. Stroke 2009;40:1907–1909.
5.
Jacobshagen C, Pax A, Unsold BW, Seidler T, Schmidt-Schweda S, Hasenfuss G, Maier LS: Effects of large volume, ice-cold intravenous fluid infusion on respiratory function in cardiac arrest survivors. Resuscitation 2009;80:1223–1228.
6.
Guluma KZ, Hemmen TM, Olsen SE, Rapp KS, Lyden PD: A trial of therapeutic hypothermia via endovascular approach in awake patients with acute ischemic stroke: methodology. Acad Emerg Med 2006;13:820–827.
7.
Greer DM, Funk SE, Reaven NL, Ouzounelli M, Uman GC: Impact of fever on outcome in patients with stroke and neurologic injury: a comprehensive meta-analysis. Stroke 2008;39:3029–3035.
8.
Reith J, Jorgensen HS, Pedersen PM, Nakayama H, Raaschou HO, Jeppesen LL, Olsen TS: Body temperature in acute stroke: relation to stroke severity, infarct size, mortality, and outcome. Lancet 1996;347:422–425.
9.
Mellergard P: Changes in human intracerebral temperature in response to different methods of brain cooling. Neurosurgery 1992;31:671–677.
10.
Wang H, Olivero W, Lanzino G, Elkins W, Rose J, Honings D, Rodde M, Burnham J, Wang D: Rapid and selective cerebral hypothermia achieved using a cooling helmet. J Neurosurg 2004;100:272–277.
11.
Keller E, Mudra R, Gugl C, Seule M, Mink S, Frohlich J: Theoretical evaluations of therapeutic systemic and local cerebral hypothermia. J Neurosci Methods 2009;178:345–349.
12.
Christensen H, Boysen G: Acceptable agreement between tympanic and rectal temperature in acute stroke patients. Int J Clin Pract 2002;56:82–84.
13.
Stemper B, Hilz MJ, Rauhut U, Neundorfer B: Evaluation of cold face test bradycardia by means of spectral analysis. Clin Auton Res 2002;12:78–83.
14.
Brown CM, Sanya EO, Hilz MJ: Effect of cold face stimulation on cerebral blood flow in humans. Brain Res Bull 2003;61:81–86.
© 2011 S. Karger AG, Basel
2011
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.