Evaluation of a Preoperative Pain Score in Response to Pressure as a Marker of Postoperative Pain and Drugs Consumption in Surgical Thyroidectomy

Abstract

INTRODUTION:: The success and effectiveness of a day surgery model are essentially related to a good postoperative course with a rapid recovery. Adequate management of analgesia during the hospital stay and after discharge becomes mandatory in reducing postoperative patient discomfort, and in facilitating discharge to home. BACKGROUND:: The aim of this study was to identify the efficacy of preoperative visual analog scale (VAS) score in predicting postoperative pain and analgesic drugs consumption. The hypothesis of a significant relation between preoperative pain and postoperative pain tolerance thresholds was tested using Spearman rank-order correlations, applied to patients scheduled for thyroidectomy in a Day Surgery Unit. METHODS:: Patients scheduled for total thyroidectomy underwent a preoperative pain test to assess the VAS value after a fixed stimulus (inflation of a sphygmomanometer with a pressure of 250 mm Hg). To estimate the power of the VAS in prediction of the postoperative analgesic requests, we divided the patients into 3 groups according to the preoperative VAS values (A group, including all patients with preoperative VAS≤3; B group including patients with preoperative VAS>3≤6; C group with preoperative VAS>6).Then we correlated preoperative results with postoperative VAS values and postoperative analgesic drug consumption, analyzing the correlation between the sensitivity and the specificity of the VAS test for a range of different cutoff values. RESULTS:: Thirty-two patients were included. A group (10 patients) showed a medium postoperative VAS<4, and required less analgesics than other groups (ketorolac, 51 mg). B group (10 patients) and C group (12 patients) showed higher postoperative VAS value and required more analgesic drug (B, 80 mg; C, 90 mg+1 g acetaminophen). Using the receiver operating characteristic or relative operating characteristic examination and calculating the underlying area , we could measure the discriminating ability of the test and found that the best VAS score cutoff was 3. CONCLUSION:: The use of a preoperative test to assess individual pain threshold may be predictive for postoperative pain and analgesic request. The mathematical and statistical model used in this study confirms that a difference in the value of VAS of 3 shall be mathematically eligible for analgesia treatment