Finger cold-induced vasodilation test does not predict subsequent cold injuries: A lesson from the 2018 Canadian Forces Exercise

Abstract

A cold-induced vasodilation (CIVD) test was administered to 113 Canadian Armed Forces (CAF) soldiers (age 25.6 ± 6 yrs) during pre-deployment to a Canadian Arctic training exercise. The incidence and rates/types of subsequent peripheral cold injuries, as well as the relationship of CIVD responses against other hypothesized/reported risk factors (smoking, gender, age, ethnicity and prior cold injury), were analyzed. Although there was a wide range of CIVD RIF (resistance index to frostbite) scores (mean = 5.0 ± 1.5), there were no systematic relationships between RIF and injury type/location and rate, and the other risk factors analyzed. The absence of physiological links to cold injury occurrence suggests that in a military cold deployment setting, other factors are in play, which might include clothing, training, leadership and doctrine. These factors should be examined in future work.

Keywords: Arctic; Canadian Armed Forces; cold; cold weather injuries; cold-induced vasodilation; frostbite; military operations.

Figure 1.

Fingertip temperature response to 30 mins of immersion in ice slurry. T_min= minimum finger temperature before CIVD reaction; T_onset= time immersed before CIVD reaction begins; T_mean= average temperature from 5−30 mins of immersion. RIF is calculated using T_min, T_onset, and T_mean.

Figure 2.

Borg pain rating every 5 min during 30 min of finger immersion (0–3 mins) and 10 mins of recovery (30–40 mins).