With the latest windchill alerts questions may be coming in from your patients about frostbite injuries, hypothermia and other concerns relating to windchill. Here are a few recent articles which may be of interest to those treating or who might be advising people. We've also selected a few web sites about windchill and frostbite from the Government of Canada and Professor Popsicle [G.G. Giesbrecht]. Two articles are not freely available but we can order them for you through MHIKNET Library Servicesmailto:mhiknet@umanitoba.ca.
1. N Engl J Med. 2011 Jan 13;364(2):189-90. doi: 10.1056/NEJMc1000538. A controlled trial of a prostacyclin and rt-PA in the treatment of severe frostbitehttp://bit.ly/1cCACGA. Cauchy E, Cheguillaume B, Chetaille E. 2. Wilderness Environ Med. 2011 Jun;22(2):156-66. doi: 10.1016/j.wem.2011.03.003. Wilderness Medical Society practice guidelines for the prevention and treatment of frostbite. McIntosh SE, Hamonko M, Freer L, Grissom CK, Auerbach PS, Rodway GW, Cochran A, Giesbrecht G, McDevitt M, Imray CH, Johnson E, Dow J, Hackett PH; Wilderness Medical Society. PMID: 21664561The Wilderness Medical Society convened an expert panel to develop a set of evidence-based guidelines for the prevention and treatment of frostbite. We present a review of pertinent pathophysiology. We then discuss primary and secondary prevention measures and therapeutic management. Recommendations are made regarding each treatment and its role in management. These recommendations are graded based on the quality of supporting evidence and balance between the benefits and risks/burdens for each modality according to methodology stipulated by the American College of Chest Physicians. 3. Crit Care Nurs Q. 2012 Jan-Mar;35(1):50-63. doi: 10.1097/CNQ.0b013e31823d3e9b. Evidence-based thermoregulation for adult trauma patients. Block J, Lilienthal M, Cullen L, White A. PMID: 22157492The purpose of this project was to develop a staff nurse-led initiative to implement and evaluate evidence-based thermoregulation care for adult trauma patients. An evidence-based practice protocol was developed and implemented, addressing varying patient needs across the spectrum of hypothermia seen in practice, serving as a guide for improving thermoregulation care in trauma patients. There were 2 key pieces to the evidence-based practice protocol. The first piece consisted of an interdisciplinary thermoregulation flowchart to provide focused care based on patient temperatures. The flowchart outlined progressive interventions for increasing hypothermia. The second piece outlined the nursing assistant role, preparing the care area before patient arrival and assisting nursing staff during trauma care. Data from staff questionnaires and patient documentation were used in a pre- and postevaluation of the practice change. Improvements were demonstrated in staff feeling better prepared to identify patients with hypothermia, treat hypothermia, and document thermal care of trauma patients. Clinically important improvement in temperature control during emergency treatment in both moderate and severe hypothermic patients were observed. Ongoing monitoring is underway to promote integration of the practice change. 4. Scand J Trauma Resusc Emerg Med. 2011 Jun 23;19:41. doi: 10.1186/1757-7241-19-41. Comparison of three different prehospital wrapping methods for preventing hypothermia--a crossover study in humans.http://1.usa.gov/1dh2mU1 Thomassen Ø, Færevik H, Østerås Ø, Sunde GA, Zakariassen E, Sandsund M, Heltne JK, Brattebø G. BACKGROUND: Accidental hypothermia increases mortality and morbidity in trauma patients. Various methods for insulating and wrapping hypothermic patients are used worldwide. The aim of this study was to compare the thermal insulating effects and comfort of bubble wrap, ambulance blankets / quilts, and Hibler's method, a low-cost method combining a plastic outer layer with an insulating layer. METHODS: Eight volunteers were dressed in moistened clothing, exposed to a cold and windy environment then wrapped using one of the three different insulation methods in random order on three different days. They were rested quietly on their back for 60 minutes in a cold climatic chamber. Skin temperature, rectal temperature, oxygen consumption were measured, and metabolic heat production was calculated. A questionnaire was used for a subjective evaluation of comfort, thermal sensation, and shivering. RESULTS: Skin temperature was significantly higher 15 minutes after wrapping using Hibler's method compared with wrapping with ambulance blankets / quilts or bubble wrap. There were no differences in core temperature between the three insulating methods. The subjects reported more shivering, they felt colder, were more uncomfortable, and had an increased heat production when using bubble wrap compared with the other two methods. Hibler's method was the volunteers preferred method for preventing hypothermia. Bubble wrap was the least effective insulating method, and seemed to require significantly higher heat production to compensate for increased heat loss. CONCLUSIONS: This study demonstrated that a combination of vapour tight layer and an additional dry insulating layer (Hibler's method) is the most efficient wrapping method to prevent heat loss, as shown by increased skin temperatures, lower metabolic rate and better thermal comfort. This should then be the method of choice when wrapping a wet patient at risk of developing hypothermia in prehospital environments.
Web sites:
* Canada's Windchill Indexhttp://bit.ly/1cCBVFx [Environment Canada; 2014] * It's Your Health - Extreme Coldhttp://bit.ly/KFU501 [Health Canada; 2013] * Accidental Hypothermiahttp://bit.ly/1kruxDx [Gordon G. Giesbrecht]