The Validity of Skin Conductance for Assessing Acute Pain in Infants: A Scoping Review.

Hu, Jiale; Modanloo, Shokoufeh; Squires, Janet; Harrold, JoAnn; Harrison, Denise

OBJECTIVES Measuring pain in infants is important but challenging, as there is no "gold standard". The measurement of skin conductance (SC) is considered as a measure of stress and a surrogate indicator of pain. To identify the extent of research conducted and to synthesize the validity evidence of SC for assessing acute pain in infants. METHODS Arksey and O'Malley's framework for scoping reviews was followed and nine electronic databases were searched. Data were analyzed thematically and presented descriptively including the following main categories: study information/details, sampling information, characteristics of participants and settings, SC outcome measures and validity evidence. RESULTS Twenty-eight studies with 1061 infants were included, including 23 cross-sectional observation studies and five interventional studies. Most studied infants with mild severity of illness (n=13) or healthy infants (n=12). The validity evidence of SC was tested in relation to referent pain measures (13 variables), stimuli (13 variables), age (2 variables) and other contextual variables (11 variables). SC was not significantly correlated with vital signs, except heart rate in two of the eight studies. SC was significantly correlated with the unidimensional behavioral pain assessment scales and crying time rather than multidimensional measurements. Fourteen of 16 studies (87.5%) showed that SC increased significantly during painful procedures. CONCLUSION Inconsistent findings on validity of SC exist. Future research should aim to identify the diagnostic test accuracy of SC compared to well-accepted referent pain measures in infants, study the validity evidence of SC in critically ill infants and employ rigorous research design and transparent reporting.