Skin temperature of the knee was effectively reduced when using a new continuous cold-flow cryocompression device: a randomised controlled crossover trial.

Objective: To determine which temperature settings on a new continuous cold-flow cryocompression device effectively reduce knee skin temperature to 10-15 °C, where pain and swelling are expected to be attenuated.

Design: Randomised controlled crossover trial.

Setting: University laboratory.

Participants: 32 healthy adult participants recruited (1 dropout) with no contraindications to cryocompressive therapy.

Intervention: A k-type thermocouple was used to record skin temperature at baseline and every five minutes during a 30-minute cryocompression treatment in a control condition and when using four different device temperature settings (6 °C, 8 °C, 10 °C, and 12 °C) on a continuous cold-flow cryocompression device. Conditions were labelled Control, Con-6, Con-8, Con-10, and Con-12, respectively.

Main Outcome Measures: Skin temperature change (°C) throughout cryocompression; time taken (mins) to achieve skin temperature < 15 °C; and the difference between final skin temperature and device temperature setting (°C).

Results: Median (IQR) skin temperature after cryocompression was 32.1 °C (29.3-33.4), 12.8 °C (12.1-14.6), 14.3 °C (13.8-15.7), 16.1 °C (15.2-17.3), and 17.7 °C (16.9-18.9) for the Control condition and Con-6, Con-8, Con-10 and Con-12, respectively. It took 20 min (Con-6) and 25 min (Con-8) for skin temperature to reach < 15 °C. A median (IQR) difference of 6.8 °C (6.1-8.6), 6.3 °C (5.8-7.7), 6.1 °C (5.2-7.3), and 5.7 °C (4.9-6.9) for Con-6, Con-8, Con-10, and Con-12, respectively was observed between device temperature setting and final skin temperature.

Conclusions: The device is recommended as it reduced skin temperature to the therapeutic range of 10-15 °C during a 30-minute treatment when using the 6 °C or 8 °C device temperature settings. Future research should determine optimal treatment lengths for cryocompression. CONTRIBUTION OF THE PAPER.