Effect of cold stimulation-induced pain on pharmacodynamic responses in healthy human volunteers

Abstract

Aims: The aim of the present study was to quantify the changes in pharmacodynamic response during cold stimulation-induced pain. Materials and Methods: In the present study we evaluated the effect of cold stimulation (immersion of hand into cold water, 1 ± 0.5°C) in 24 healthy human subjects. Change in skin conductance (in the form of galvanic skin response), skin temperature, and heart rate were recorded using the Data Acquisition System (Biopac mp 150). Results: There was significant increase in skin conductance (P<0.001) from 0.22 ± 0.19 microSiemens to 0.32 ± 0.27 microSiemens, with 58.3% increase from the baseline. The heart rate also significantly increased by 8.3% (P<0.001) from 85.6 ± 15.1 bpm to 92.2 ± 14.2 bpm. There was no significant change in skin temperature. Conclusion: The findings of this study showed that an increase in skin conductance seemed to be a good indicator of acute pain. The changes in skin conductance were influenced by acute pain; therefore, monitoring skin conductance could be used as a pharmacodynamic parameter in the evaluation of analgesic agents.