In Vivo Tissue Temperature Comparison of Cryotherapy With and Without External Compression

Abstract

Study objective: To compare the tissue-cooling efficiency of external cryotherapy with and without adjunctive compression. Methods: We conducted an experimental repeated-measures study in which each of the 11 anesthetized subject dogs served as its own control. A chemical instant cold pack was applied to each subject's ventral thighs. One pack was held in position by gravity, and the other was compressed against the musculature with a tubular elastic wrap. Baseline and subsequent temperature measurements were taken every 10 minutes for 1 hour with the use of an IM temperature probe percutaneously inserted into each subject's hind legs. Results: IM temperatures were not significantly different at baseline and were coldest at 20 minutes; they increased slowly thereafter. The recorded temperature was lower under the compressed cold pack ( P=.003), and changes over time for both groups were also significant ( P=.005). The instantaneous temperature difference at 10, 30, 40, 50, and 60 minutes was also significant. Conclusion: Externally applied instant cold packs in a dog model caused local tissue hypothermia that peaked by 20 minutes, persisted for at least 1 hour, and was significantly augmented by adjunctive compression. Further research is needed to evaluate the clinical efficacy and safety of these interventions in the management of acute soft-tissue injuries. [Barlas D, Homan CS, Thode HC Jr: In vivo temperature comparison of cryotherapy with and without external compression. Ann Emerg Med October 1996;28:436-439.]