Monitoring electrical skin conductance: a tool for the assessment of postoperative pain in children?

BACKGROUND

Monitoring changes in electrical skin conductance has been described as a potentially useful tool for the detection of acute pain in adults. The aim of this study was to test the method in pediatric patients.

METHODS

A total of 180 postoperative pediatric patients aged 1-16 yr were included in this prospective, blinded observational study. After arrival in the recovery unit, pain was assessed by standard clinical pain assessment tools (1-3 yr: Face Legs Activity Cry Consolability Scale, 4-7 yr: Revised Faces Scale, 8-16 yr: Visual Analogue Scale) at various time points during their stay in the recovery room. The number of fluctuations in skin conductance per second (NFSC) was recorded simultaneously.

RESULTS

Data from 165 children were used for statistical analysis, and 15 patients were excluded. The area under the Receiver Operating Characteristic curve for predicting moderate to severe pain from NFSC was 0.82 (95% confidence interval 0.79-0.85). Over all age groups, an NFSC cutoff value of 0.13 was found to distinguish between no or mild versus moderate or severe pain with a sensitivity of 90% and a specificity of 64% (positive predictive value 35%, negative predictive value 97%).

CONCLUSIONS

NFSC accurately predicted the absence of moderate to severe pain in postoperative pediatric patients. The measurement of NFSC may therefore provide an additional tool for pain assessment in this group of patients. However, more research is needed to prospectively investigate the observations made in this study and to determine the clinical applicability of the method.