Effect of the perioperative infusion of dexmedetomidine on chronic pain after breast surgery

Abstract
Background: This prospective double-blind trial was undertaken to analyze the role of perioperatively administered dexmedetomidine on the occurrence of chronic pain in cases undergoing surgery for breast cancer. Subjects and Methods: Eighty-six cases were randomly assigned to two groups to receive either dexmedetomidine (2 μg/ml) in group D or saline in group C, in a loading dose of 0.5 ml/kg, intravenous (IV), 30 min prior to induction, followed by a continuous infusion of 0.25 ml/kg/h IV till the completion of surgery, and then the dose tapered to 0.1 ml/kg/h for up to 24 h. The standardized questionnaires that measured chronic pain (Brief Pain Inventory, BPI; Short Form McGill Pain Questionnaire, SF-MPQ2) and quality of life (Quality of Life Scale, QOLS) were gathered after 3 months of surgery as a primary outcome. Pain (verbal numerical score, VNS), sedation scores (Ramsay scoring), and analgesic requirements were also assessed for 72 h postoperatively. Results: In total, 84 cases (n=42) were analyzed for acute pain and 69 (34 in group D and 35 in group C) for chronic pain. The consumption of isoflurane/fentanyl intra-operatively and paracetamol postoperatively was significantly lower in Group D. The sedation scores were non-significant between the groups. The VNS at rest and after movement was significantly lower in group D at corresponding times (except at 60 min) throughout the assessment period. The BPI and SF-MPQ2 scores were significantly lower in group D in most of the factors. The QOLS score was significantly better in group D in all items except for relationships, friends, and learning. Conclusion: The perioperative infusion of dexmedetomidine has a pivotal role in attenuating the incidence and severity of chronic pain and improving the quality of life in cases undergoing breast cancer surgery.