Posterior spinal fusion is a major surgical procedure performed to treat back pain or nerve injury associated with spinal instability due to degenerative disease, trauma, pathological fractures or compression from tumours. It is associated with significant post-operative pain and high analgesia requirements despite the widespread use of perioperative multi-modal analgesia. This is a significant problem to address, as poorly controlled post-operative pain is associated with increased morbidity such as delayed functional recovery, quality of life, prolonged opioid use and increased risk of developing persistent post-surgical neuropathic pain. In recent years, dexmedetomidine, an alpha2-agonist with anxiolytic, anaesthetic sparing and analgesic effects has been used in various surgical settings and has been shown to reduce pain and opioid consumption. Additionally, as an opioid sparing agent, dexmedetomidine may have an important role to decrease opioid related harms. However, its effectiveness as an analgesic agent when used during spinal fusion surgeries has not been conclusive demonstrated due to heterogeneity of available data.
The Spinal Procedure Analgesia with Dexmedetomidine (SPADE) Study will assess if the addition of intra-operative infusion of dexmedetomidine to standard practice is an effective treatment for pain after posterior spinal fusion surgery. The trial is a prospective double-blinded randomised controlled trial without crossover, recruiting adult patients 18 years or older having posterior thoracic and/or lumbar spinal fusion surgery. Patients are randomised to receive either dexmedetomidine infusion or placebo intra-operatively in addition to standard multi-modal analgesia. The primary objective is to determine if intra-operative administration of dexmedetomidine will lead to a significant reduction in patient reported numerical rating scale (NRS) pain score at 1 hour post-operatively in patients undergoing thoracic and/or lumbar spinal fusion surgery compared to standard practice. The secondary objectives are to compare the administration of intra-operative dexmedetomidine infusion to standard practice with regards to; first NRS pain score in Post Anaesthesia Care Unit (PACU), NRS pain scores at 24 hours and at 3 months post-operatively, total opioid consumption (as oral morphine equivalent) at 24 hours post-operatively, and functional ability at 3 months as measured using the World Health Organisation Disability Assessment Schedule 2.0 (WHODAS 2.0) tool.
The overall aim of the SPADE study is to add further information on dexmedetomidine’s potential role in complex spine surgery to the existing body of evidence for its use in this context. A positive finding will provide a role for adding dexmedetomidine as part of a multi-modal approach to pain management in these patients, with subsequent potential reduction in opioid use and its adverse effects. Additionally, if found to have significant effects on functional recovery and pain at three months, our findings may signal further investigation into dexmedetomidine’s role on persistent pain management.
Dr Alex Koh, Dr Kaylee Jordan, Dr Jonathan Chiong, Royal Melbourne Hospital, Melbourne.
The project was awarded $A12,830 through the ANZCA research grants program for 2022.