Regional nerve block
Sympathectomy has been replaced by the use of iloprost which is a reversible intervention and has a similar effect. Studies have shown promising results for distal volar forearm nerve blocks using lidocaine to create both an analgesic effect and hyperaemia of the affected area. Digital blocks using bupivacaine have been shown to treat both pain and vasoconstriction seen in acute fingertip frostbite, with effects lasting up to 15 hours.[47]Pasquier M, Ruffinen GZ, Brugger H, et al. Pre-hospital wrist block for digital frostbite injuries. High Alt Med Biol. 2012 Mar;13(1):65-6.
http://www.ncbi.nlm.nih.gov/pubmed/22429237?tool=bestpractice.com
[48]Calder K, Chung B, O'Brien C, et al. Bupivacaine digital blocks: how long is the pain relief and temperature elevation? Plast Reconstr Surg. 2013 May;131(5):1098-104.
http://www.ncbi.nlm.nih.gov/pubmed/23629091?tool=bestpractice.com
[49]Chandran GJ, Chung B, Lalonde J, et al. The hyperthermic effect of a distal volar forearm nerve block: a possible treatment of acute digital frostbite injuries? Plast Reconstr Surg. 2010 Sep;126(3):946-50.
http://www.ncbi.nlm.nih.gov/pubmed/20811227?tool=bestpractice.com
Hyperbaric oxygen therapy
Hyperbaric oxygen therapy (HBOT) increases the deformability of red blood cells, decreases oedema formation in ischaemic tissues, and has some bacteriostatic effects. Its efficacy in frostbite depends on the extent of thrombosis of the microvasculature.[14]Handford C, Buxton P, Russell K, et al. Frostbite: a practical approach to hospital management. Extrem Physiol Med. 2014 Apr 22;3:7.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3994495
http://www.ncbi.nlm.nih.gov/pubmed/24764516?tool=bestpractice.com
Anecdotal cases of frostbite patients treated with HBOT have demonstrated promising results.[50]Folio LR, Arkin K, Butler WP. Frostbite in a mountain climber treated with hyperbaric oxygen: case report. Mil Med. 2007 May;172(5):560-3.
http://www.ncbi.nlm.nih.gov/pubmed/17521112?tool=bestpractice.com
[51]von Heimburg D, Noah EM, Sieckmann UP, et al. Hyperbaric oxygen treatment in deep frostbite of both hands in a boy. Burns. 2001 Jun;27(4):404-8.
http://www.ncbi.nlm.nih.gov/pubmed/11348755?tool=bestpractice.com
Early wound demarcation and tissue preservation was reported in 2 patients who received delayed (28 days post-injury) HBOT for severe frostbite injuries.[52]Lansdorp CA, Roukema GR, Boonstra O, et al. Delayed treatment of frostbite with hyperbaric oxygen: a report of two cases. Undersea Hyperb Med. 2017 Jul-Aug;44(4):365-9.
http://www.ncbi.nlm.nih.gov/pubmed/28783893?tool=bestpractice.com
Pentoxifylline
Pentoxifylline increases red blood cell flexibility, thereby aiding revascularisation. There are anecdotal reports of benefit in humans.[53]Bilgiç S, Ozkan H, Ozenç S, et al. Treating frostbite. Can Fam Physician. 2008 Mar;54(3):361-3.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2278351
http://www.ncbi.nlm.nih.gov/pubmed/18337529?tool=bestpractice.com
[54]Purkayastha SS, Bhaumik G, Chauhen SK, et al. Immediate treatment of frostbite using rapid re-warming in tea decoction followed by combined therapy of pentoxyfylline, aspirin and vitamin C. Indian J Med Res. 2002 Jul;116:29-34.
http://www.ncbi.nlm.nih.gov/pubmed/12514975?tool=bestpractice.com
[55]Hayes DW Jr, Mandracchia VJ, Considine C, et al. Pentoxifylline: adjunctive therapy in the treatment of pedal frostbite. Clin Podiatr Med Surg. 2000 Oct;17(4):715-22.
http://www.ncbi.nlm.nih.gov/pubmed/11070801?tool=bestpractice.com
Botulinum toxin
In one case study, botulinum toxin type A injections improved skin perfusion, cold hypersensitivity, and pain in a patient with frostbite sequelae.[56]Norheim AJ, Mercer J, Musial F, et al. A new treatment for frostbite sequelae; Botulinum toxin. Int J Circumpolar Health. 2017;76(1):1273677.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5328352
http://www.ncbi.nlm.nih.gov/pubmed/28452678?tool=bestpractice.com
Post-procedure angiography showed improved dilation of the digital arteries compared with studies performed before botulinum toxin injection.
Wound dressings
A reduced number of dressing changes may decrease pain, and increase patient satisfaction with the use of hydrofiber silver dressings (typically used for thermal burns) in frostbite patients.[16]Kiss TL. Critical care for frostbite. Crit Care Nurs Clin North Am. 2012 Dec;24(4):581-91.
http://www.ncbi.nlm.nih.gov/pubmed/23089662?tool=bestpractice.com
Similar results in frostbite studies have been reported with an alloplastic skin substitute also used in the management of thermal burns.[57]Madry R, Struzyna J, Stachura-Kulach A, et al. Effectiveness of Suprathel® application in partial thickness burns, frostbites and Lyell syndrome treatment. Pol Przegl Chir. 2011 Oct;83(10):541-8.
http://www.ncbi.nlm.nih.gov/pubmed/22189281?tool=bestpractice.com
Better results were observed when the dressing was applied within 24 hours of injury. Substantial oedema post-rewarming should be anticipated, and circumferential dressings should be wrapped loosely to allow for the swelling, without placing pressure on the underlying tissue.[33]UK Government Ministry of Defence: Defence and armed forces guidance. JSP539: heat illness and cold injury: medical management part 2 guidance. Feb 2021 [internet publication].
https://www.gov.uk/government/publications/prevention-of-climatic-injuries-in-the-armed-forces-medical-policy/jsp-539-heat-illness-and-cold-injury-medical-management-part-2-guidance-accessible-version-february-2021