Send letter to journal:
Re: The myths of RICE: Crucial issues of intermittent cryotherapy and compression in sports traumatology

Dear editor,

We read with great interest the recent work of Dr. Algafly und Dr. George regarding the effect of sole cryotherapy on nerve conduction velocity, pain threshold and pain tolerance in healthy volunteers. We would like to thank the authors for their important contribution, but we would further appreciate commenting on some issues raised by the authors.

The ankle was focussed in this study using crushed ice, which was applied on average for 26min (range 20-31min) to achieve a skin temperature of 10°C. For each 1 degree fall in skin temperature, the authors found a decrease of sensory nerve conduction velocity of 0.4m/s among their subjects. We fully agree with the authors that further studies are mandatory. Especially, since the RICE regimen incorporates not only cryotherapy, but also compression, elevation and rest, we do not know to what extent sole cryotherapy works in this mosaic. Actually, besides the neurological point of view, we found tissue microcirculation to be modified tremendously following sole cryotherapy, if applied intermittent for 3x10min [1]. Among thirty volunteers, superficial capillary blood flow was reduced from 42 relative units (rU) to 6rU in the 1st, 5rU in the 2nd and 3rU in the 3rd cryotherapy period (-65%, p=0.0003) with no significant capillary hyperaemia. Superficial tendon oxygen saturation dropped significantly from 43% to 26/18/11% (p=0.0004) after repetitive cryotherapy with persisting increase of tendon oxygenation during rewarming (51/49/54%, p=0.077) up to +27% of the baseline level. Relative postcapillary venous tendon filling pressures were favourably reduced from 41+/-11rU to 31/28/26rU (-36%, p=0.0004) superficially and deep from 56+/- 11rU to 45/46/48rU (-18%, p=0.0001) during cryotherapy facilitating capillary venous clearance. Therefore a facilitation of postcapillary venous outflow is associated with sole cryotherapy applied for 3x10min only which might have a direct effect on pain level as well due to reduced tissue tension. This data is supported by a recent controlled laboratory study stating that prolonged cooling reduces microvascular dysfunction, inflammation, and structural impairment [2].

The intermittent cryotherapy seems to be favourable to use, since the superb Bleakley study, where they randomized 44 sportsmen and 45 general public subjects with moderate ankle sprains for either 20min of single cryotherapy or intermittent cryotherapy for 10 minutes with 10min of rewarming and a second 10min of cryotherapy and 10min of reperfusion with this cycle being repeated every two hours [3]. Subjects treated with the intermittent protocol had significantly (p<0.05) less ankle pain on activity than those using a standard 20 minute protocol; however, one week after ankle injury, there were no significant differences between groups in terms of function, swelling, or pain at rest. Therefore based on these results it would be appropriate to examine the effects of only 10minutes of cryotherapy in an intermittent regiment regarding the nerve conduction velocity to elucidate its value. 25 or even 30minutes of continuous ice application are in our personal view not that effective at least both, from a microcirculatory and a clinical point of view [1,2] and might lead to an adverse reaction, such as a frostbite at the gym [4].

References

[1] Knobloch K, Grasemann R, Spies M, Vogt PM. Intermittent KoldBlue(R) cryotherapy of 3x10min changes mid-portion Achilles tendon microcirculation. Br J Sports Med 2006, Nov 30.

[2] Schaser KJ, Disch AC, Stover JF, Lauffer A, Bail JH, Mittlmeier T. Prolonged superficial local cryotherapy attenuates microcirculatory impairment, regional inflammation, and muscle necrosis after closed soft tissue injury in rats. Am J Sports Med 2007;34(1):93-102.

[3] Bleakley CM, McDonugh SM, MacAuley DC. Cryotherapy for acute ankle sprains: a randomised controlled study of two different icing protocols. Br J Sports Med 2006;40:700-5.

[4] O'Toole G, Rayatt S. Frostbite at the gym: a case report of an ice pack burn. Br J Sports Med 1999;33(4):278-9.