The acute effects of cold, CO2 containing forearm water both on skin microcirculation and pain thresholds

Abstract

Purpose: The study was arranged to investigate the immediate effects of high concentrated CO2 containing cold water bath on the microcirculation of the skin, on the pain thresholds (pressure, heat, cold) and on the local subjective heat sensitivity and the thermal comfort perception. Material and method: 17 healthy male subjects got unilateral forearm baths with mineral water containing 3500 mg/l CO2 and with tap water respectively. Both baths were carried out at a temperature of 18-19degreesC and the duration of the baths was 16 minutes. Results: During the application Of CO2 bath, a 2 fold increase in the skin microcirculation values was measured via Laser Doppler Flowmetry in comparison with the initial values. However, during tap water bath application, skin blood flow values were decreased 50%. The difference was statistically significant (p < 0.001). Furthermore the subjects mentioned that they felt warmer (p < 0.05) and more comfortable (p < 0.01) with CO2 containing water bath. But despite the improvement in the values there were not any statistically significant differences between the baths for the pressure pain threshold (+16.7%; p<0.01), the cold pain threshold (-41.6%; p < 0.05) and the heat pain threshold (+2.5%, n.s.). Conclusion: Our findings indicate that CO2 containing cold water bath is more effective in increasing the skin microcirculation, inhibiting the cold dependent vasoconstriction and leading to a warm and more comfortable subjective sensation in comparison with tap water. The analgesic effects were similar for both baths.