Infrared Thermographic Analysis of Surface Temperature of the Hands During Exposure to Normobaric Hypoxia

Abstract

Jones, Daniel, Samuel F. Covins, Gavin E. Miller, Kenneth I. Morrison, Alexander G. Clark, Samuel D. Calcott, Alasdair M. Anderson, Samuel J.E. Lucas, Christopher H.E. Imray, and the Warwick Altitude Research Group. Infrared red thermographic analysis of surface temperature of the hands during exposure to normobaric hypoxia. High Alt Med Biol. 00:000-000, 2018.-Frostbite and other cold-related injuries commonly develop during prolonged exposure to the low environmental temperatures of polar and mountainous regions. Hypoxia is a potent sympathetic stimulus that causes vasoconstriction of the peripheral blood vessels, which may further compound the risk of developing a cold-related injury during high-altitude exposure. To investigate this, we utilized portable infrared thermographic technology to quantitatively measure changes in the surface temperature of the hands during exposure to increasing levels of normobaric hypoxia in a temperature-controlled high-altitude simulation. Surface temperature was assessed at four anatomical locations on both the left and right hands in a cohort of 10 healthy male participants at a series of predetermined levels of hypoxia (0.20 fraction of inspired oxygen [FO] [pre- and postexposure], 0.172 FO, 0.145 FO, 0.128 FO). Thermographic analysis revealed an overall decrease in peripheral temperature across the anatomical regions of the hands as the hypoxic stimulus increased, with statistically significant reductions observed at all four anatomical sites during exposure to 0.128 FO (p < 0.05). These findings demonstrate that portable infrared thermography can be used to detect reductions in peripheral surface body temperature during exposure to normobaric hypoxia.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2024 Update

“…Preventive measures to ensure local tissue perfusion include: 1) maintaining adequate core temperature and body hydration; 2) minimizing the effects of known diseases, medications, and substances that might decrease perfusion (including awareness and symptoms of alcohol and drug use); 3) covering all skin and the scalp to insulate from the cold; 4) minimizing blood flow restriction, such as occurs with constrictive clothing, footwear, or immobility; 5) ensuring adequate nutrition; and 6) using supplemental oxygen in severely hypoxic conditions (eg, >7500 m). 14 Recommendation: Strong recommendation, low-quality evidence.…”

“…These measures include the following: 1) avoiding environmental conditions that predispose to frostbite, specifically below 0 °C (some risk 0 to −15 °C and increasing risk below −15 °C, even with low wind speeds) 18 ; 2) protecting skin from moisture, wind, and cold; 3) avoiding perspiration or wet extremities; 4) increasing insulation and skin protection (eg, by adding clothing layers, changing from gloves to mitts); 5) ensuring beneficial behavioral responses to changing environmental conditions (eg, not being under the influence of illicit drugs, alcohol, or extreme hypoxemia) 19 ; 6) using chemical hand and foot warmers and electric foot warmers to maintain peripheral warmth (note: warmers should be close to body temperature before being activated and must not be placed directly against skin or constrict flow if used within a boot); 7) regularly checking oneself and the group for extremity numbness or pain and warming the digits and/or extremities as soon as possible if there is concern that frostbite may be developing; 8) recognizing frostnip or superficial frostbite before it becomes more serious; and 9) minimizing duration of cold exposure. 14 Emollients do not protect against-and might even increase-the risk of frostbite. 20 The time that a digit or extremity can remain numb before developing frostbite is unknown; thus, digits or extremities with paresthesia should be warmed as soon as possible.…”

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2019 Update

“…One small study that measured hand temperature at normobaric hypoxia found decreased skin temperatures with decreasing F I O 2 . 39 However, hyperoxia has been found to cause vasoconstriction in the extremities 40 ; therefore, oxygen should not be applied routinely to patients who are not hypoxic. Although evidence is lacking to support use of supplemental oxygen for frostbite, oxygen may be delivered by face mask or nasal cannula if the patient is hypoxic (oxygen saturation <88%) or at high altitude above 4000 m. Recommendation Grade: 2C.…”

“…Other potential useful imaging techniques include Doppler ultrasound 55 ; triple phase technitium 58,67 ; indocyanine green microangiography 68 ; and thermal imaging. 39 Although some of these techniques show potential, further studies are required to determine their exact role.…”

Análise Termográfica E Algométrica Das Mãos De Universitários Que Utilizam Telefone Móvel / Thermographic and Algometric Analysis of Hands of Students Using Mobile Phone

“…Outra condição que pode ser evidenciada nas mãos devido ao uso excessivo, são as alterações térmicas relacionadas a mudanças do fluxo sanguíneo. A termografia infravermelha é um instrumento de análise não invasivo e não radioativo, capaz de observar alterações do perfil térmico, sendo muito utilizado em atividades desportivas para controle da carga aplicada ao treinamento, visando identificar alterações fisiológicas que levam a fadiga 14,15…”