UTILITY OF A SALIVARY BIOSENSOR FOR OBJECTIVE ASSESSMENT OF SURGERY-RELATED STRESS
MATERIALS AND METHODS: A prospective, cohort study of 76 healthy subjects who underwent elective removal of their third molars between April 2010 and February 2011 was conducted. Along with subjects’ self-reports of anxiety and pain, biosensor-facilitated measurements of sAA levels were obtained at multiple time points during the preoperative consult, surgery, and post-surgical follow-up visits. Additionally, subjects completed the Pain Catastrophizing Scale (PCS) at baseline during their preoperative visit. The 13-item PCS measures the degree to which individuals cope with painful experiences with cognitive activities that exacerbate the fearful aspects of their pain experience. During each visit, participants completed multiple single-item, self- reports of anxiety, pain, and calm during each saliva sampling.
STATISTICAL ANALYSIS: Using mixed effects models with a random intercept and a first-order auto- regressive covariance structure for repeated measures, sAA levels measure by the biosensor were examined for any changes within and between the three visits. The changes in self-reported pain, anxiety, and calmness ratings, collected four times within each visit, were also investigated using mixed effects models with the same structure. Mixed models were built using the log(x) transformed sAA readings as the outcome, with PCS, self-reported anxiety, pain, and calmness, and time as covariates. Other mixed models examined to the relationship between PCS subscales and changes in self-reported anxiety, pain, and calm over time.
RESULTS: sAA levels were lower during surgery and post-surgical follow-up compared to the consult visit (p < .01). sAA decreased during the surgery visit (p < .05), and did not change during the consult or follow-up visits. Individuals who reported greater helplessness responses to pain manifested higher sAA levels during the surgery visit (p < .05). Self-reported anxiety ratings were highest during the surgery visit, and pain ratings were highest during the follow-up visit.
CONCLUSION: sAA did not show predicted elevations during the surgery visit compared to the consult and post-surgical follow-up visits, or increases during the surgery visit. However, individuals who reported responding to pain with helplessness had larger sAA levels in anticipation of surgery, providing proof of concept for the value of point-of-care assessments of surgery-induced stresses and the differential effect of personality traits. Portable stress measurement devices such as the sAA biosensor can help surgeons measure underlying psychological differences and predict a patient's postoperative response, thus allowing individualized antianxiety strategies and pain medication.
1. Nater UM, Rohleder N, Gaab J, Berger S, Jud A, Kirschbaum C, Ehlert U. Human salivary alpha-amylase reactivity in a psychosocial stress paradigm. International Journal of Psychophysiology 2005 Mar;55(3):333-342.
2. Chatterton RT, Vogelsong KM, Lu YC, Ellman AB, Hudgens GA. Salivary alpha-amylase as a measure of endogenous adrenergic activity. Clin Physiol 1996 Jul;16(4):433-448.