PERSISTENCE OF CRYOTHERAPY INDUCED ISCHEMIA FOR HOURS AFTER COOLING ENDS

摘要

Orthopedic surgery and sports medicine commonly use cryotherapy to reduce inflammation, alleviate pain, lower the chance of secondary hypoxic injury, and decrease hematoma formation. Methods of cryotherapy vary widely in their sophistication, ranging from bags of ice or freezable gel packs to liquid perfusion cryotherapy devices. These perfusion cryotherapy devices circulate near 0°C water through a flexible bladder, resulting in localized tissue cooling. There is currently no consensus on the proper duration or frequency of cooling. Over one thousand adverse outcomes have been reported, including full thickness skin necrosis and neuropathy. It is thought that localized ischemia induced by cryotherapy may be the cause of these adverse outcomes. However, there is relatively little data describing details of the vascular physiology response to cooling. We have performed in excess of 100 human subject experiments to better quantify the occurrence, magnitude, and persistence of cold-induced ischemia associated with cryotherapy. We have observed a ubiquitous persistent and significant degree of vasoconstriction as a result of localized cooling. In this paper we present data from a subset of these experiments.