O98 A prospective, randomized, double-blind, parallel-group, sham-controlled study of the effect of anodal tDCS on acute post-thoracotomy pain

Objectives Acute post-thoracotomy pain (PTP) represents one of the strongest by the intensity of postoperative pains. In this study, we investigate the effectiveness of tDCS, as the adjunctive treatment combined with patient standard postoperative analgesia after thoracotomy. Methods In total, 33 patients in which thoracotomy are carried out due to malignant disease were treated with patient-controlled analgesia (PCA) by morphine for the purpose of post-operative pain control. In addition, patients were randomized to double-blind parallel-group trial of anodal tDCS (1.2 mA, 0.048 mA/cm2, 20 min), over M-1 (13 pts) vs. sham tDCS (20 pts) added on to PCA, as long as analgesia was needed (5 days at longest). The outcome measures were the amount of morphine used for pain control (primary), and several VAS pain scores, in rest, during movements and cough (secondary), at several time points. Results Cumulative morphine dose for a period of five postoperative days was lower in the group treated with anodal tDCS, as add-on therapy, compared to sham-tDCS (82.7 ± 74.5 vs 121.6 ± 62.3 mg, p  = 0.033). In the first 24 postoperative hours, VAS pain scores in rest (AUC 200.2 vs 223.0, p  = 0.45) and during the movement (AUC 330.8 vs 394.4 p  = 0.10) were unchanged while the significant difference was shown only for VAS pain during a cough (AUC 358.8 vs 444.9, p  = 0.024). Conclusion The addition of anodal tDCS, over M-1, daily in patients with acute PTP resulted in significant reduction of cumulative morphine dose and VAS as the measure of perceived pain during a cough. ClinicalTrials.gov Identifier: NCT03005548.