Abstract
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
- The Physiolab S1 cryocompression device allows users to determine precise temperatures of the ice-water that is circulated around the knee during a treatment.
- This paper demonstrates the ability of each temperature setting to reduce skin temperature around the knee to within the target therapeutic range of 10–15 °C.
- There is a significant discrepancy between the temperature setting of the device and the skin temperature achieved during a treatment.
- Clinicians should not assume that all temperature settings on this and similar devices sufficiently reduce skin temperature of the knee to confer a therapeutic benefit.