Objectives: To examine the relationship among different indicators of pain and distress, including self-report, behavioral observations, and physiological parameters, in children with cancer undergoing invasive procedures.
Methods: Forty-eight children between the ages of 3.1 and 17.7 years were evaluated while undergoing lumbar punctures. Self-report measures assessed anxiety, pain, self-efficacy, expectations of coping strategies, and coping self-efficacy. Parents reported on their own and their child's levels of anxiety, and physicians estimated their own level of stress and technical difficulty in completing the procedure. Behavioral observations were made prior to, during, and after the procedure. Physiological parameters included heart rate, cardiac vagal tone, and salivary cortisol. At the discretion of attending physicians, 32 children received deep sedation, 9 received light sedation, and 7 received cognitive-behavioral strategies with topical anesthetic as interventions to manage procedural distress.
Results: There was a high degree of consistency within self-report, behavioral, and physiological parameters, but correlations between measures in different modalities were low. There were floor effects for most behavioral and self-report measures of distress. Cortisol showed marked changes preprocedure to postprocedure, demonstrating high levels of physiological response despite lack of apparent or perceived discomfort. Heart rate was significantly lower in the group using cognitive-behavioral techniques, especially at the point of needle insertion.
Discussion: Self-report measures, behavioral indicators, and physiological changes are not interchangeable outcomes. Treatment strategies were effective for minimizing subjective and behavioral distress, but not necessarily for physiological reactions. Future research should focus on individual differences in these responses, and treatment outcome studies aimed at reducing distress must be clear about the specific goals of intervention.