Chronic Wound Care Management and Research (Aug 2014)
Objective evaluation for venous leg ulcer-related nociceptive pain using thermography
Abstract
Taichi Goto,1 Ayumi Naito,1,2 Nao Tamai,1 Gojiro Nakagami,1 Makoto Mo,3 Hiromi Sanada1 1Department of Gerontological Nursing/Wound Care Management, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo, Japan; 2Fujisawa City Hospital, Fujisawa, Kanagawa, Japan; 3Department of Cardiovascular Surgery, Yokohama Minami Kyosai Hospital, Yokohama, Kanagawa, Japan Purpose: We aimed to identify distinguishing characteristics in thermographic images of venous leg ulcer (VLU), for objective evaluation of VLU-related nociceptive pain. Patients and methods: Secondary analysis was performed, using existing data obtained from April to November 2010, for patients with VLU. Thermographic images of wounds and their surrounding area were classified according to the periwound temperature pattern as "normal temperature" or "high temperature". These results were compared with the self-reported pain intensity assessed by the short-form McGill Pain Questionnaire. Cohen's kappa coefficients were used to evaluate the interrater reliability for temperature assessment, and Wilcoxon rank sum test was used to compare pain intensities between the two groups. Results: Among 39 thermographic examinations in eight patients, 22 were classified into the high-temperature group and 17 into the normal-temperature group. Kappa coefficients for the temperature classification were 0.90 between the wound, ostomy, and continence nurse and a wound care specialist, and 0.90 between the wound, ostomy, and continence nurse and a graduate student. The pain rating index (Z=−2.981, P=0.003), sensory pain (Z=−3.083, P=0.002), affective pain (Z=−2.764, P=0.006), and present pain intensity (Z=−2.639, P=0.006) ratings were significantly higher in the high-temperature group than in the normal-temperature group, but the visual analog scale (Z=−0.632, P=0.527) was not significantly different between the two groups. Conclusion: Thermographic pattern may reflect VLU-related nociceptive pain due to inflammation and has the possibility of being an easy and rapid tool for objective pain evaluation. Keywords: short-form McGill Pain Questionnaire, temperature, wound assessment
