Monitoring of skin conductance to assess postoperative pain intensity

Pain is known to alter the electrogalvanic properties of the skin. The aim of this pilot study was to investigate the influence of postoperative pain on skin conductance (SC) readings. After obtaining ethical approval and written informed consent, 25 postoperative patients were asked to quantify their level of pain on a numeric rating scale (NRS, 0–10) at different time points in the recovery room. As a parameter of SC, the number of fluctuations within the mean SC per second (NFSC) was recorded. Simultaneously, the NRS was obtained from patients by a different observer who was blinded to the NFSC values. Data from 110 readings of 25 patients (14 female, 11 male; 21–67 yr) were included. NFSC showed a significant correlation with the NRS (r=0.625; P