(475) Identification of peri-operative pain-related biomarkers for adolescent spine surgery

Abstract

Pediatric pain management could be substantially improved by the existence of objective biomarkers that can guide treatment decision-making. The objective of this longitudinal observational investigation is to identify associations between the expression of pain-related biomarkers in physiological fluids and the experience of pain in a pediatric population in the peri-operative period. Study participants undergoing spinal surgery for adolescent idiopathic scoliosis completed validated pain questionnaires on the pre-operative consult visit (∼1 week pre-op), 48 hours post-surgery, and on their first post-operative visit (∼4 weeks post-op). During the pre-operative consult, saliva and blood samples were collected. Samples were also collected on the day of surgery, with the addition of a cerebrospinal fluid sample. Finally, saliva and blood samples were collected again 48 hours and 4 weeks post-surgery. Biomarkers were analyzed using commercially available ELISA kits according to the manufacturers’ instructions. The severity of the scoliosis was not related with post-operative pain at any time point or with any other psychosocial variables (P>0.05). Patients’ subjective pain report was significantly increased immediately after surgery but returned to pre-operative values within 4 weeks. Biomarker concentrations demonstrated variation over time such as significant increases in cortisol on the day of surgery and IL-6 up-regulation 48 hours post-surgery (P<0.05). Preliminary analysis suggests that high pre-operative concentrations of cortisol correlate to an increase in patient-controlled analgesia (PCA) attempts in the first 24 hours post-surgery. These preliminary results provide proof-of-concept that pre-operative biomarkers can predict post-operative pain management and validate our experimental approach for the identification of pain-specific biomarkers. Biomarker analysis may therefore provide a deeper understanding of a patient’s pain perception and potentially serve as objective quantitative predictors of children’s post-operative pain burden.