Measurement of reactive vasodilation during cold gel pack application to nontraumatized ankles.

Conflicting results regarding local vascular response during cryotherapy have been reported in the literature. The purpose of this study was to determine whether application of a cold pack reduced blood volume in a nontraumatized ankle. Thirteen subjects ranging in age from 18 to 30 years (X = 22; SD = 3.9) participated in the study. An impedance plethysmograph, in combination with venous occlusion, was used to measure the changes in local blood volume at the ankle over a 20-minute period for the following three conditions: rest, room-temperature gel pack application, and cold gel pack application. A significant reduction in local blood volume was found for the cold gel pack condition in comparison with the resting condition. This reduction was attributed to a combination of pressure from the weight of the cold gel pack and the pack's temperature. Maximum decrease in blood volume occurred at 13.5 minutes after cold gel pack application. Reactive vasodilation was not observed. The results lend support to the clinical use of a cold gel pack when a reduction in local circulation is desired, such as in the management of acute-phase soft tissue trauma.