Title: A randomised controlled trial to investigate the effectiveness of pectoralis-intercostal-rectus sheath plane block in reducing chronic post-sternotomy pain after cardiac surgery: to study feasibility for a substantive trial nerve blOck in caRdIac surGery chronic paIN (ORIGIN-feasibility trial)
Funder: Department of Health and Social Care

Abstract: Research question In adult patients undergoing Coronary Artery Bypass Grafting (CABG) surgery, does perioperative pectoralis intercostal rectus sheath plane block (PIRS) result in improved clinical and cost effectiveness compared to usual analgesia without PIRS? Background CABG remains a crucial surgical intervention for the prevention of myocardial infarction in patients with cardiovascular disease. CABG involves sternotomy and the harvesting of the saphenous vein from the leg, which is used as a graft for the diseased coronary arteries. Both, sternotomy and leg incisions, are associated with intense post-operative pain which can lead to chronic post-sternotomy pain (CPSP): a highly debilitating neuropathic pain condition which can affect up to 50% of patients, and that represents a significant health and economic burden for the NHS. Analgesia for CABG is notoriously challenging. Current practice utilises intravenous opioids as the mainstay of perioperative pain management. However, opiate-based analgesia often hinders postoperative recovery by causing nausea, vomiting, delirium and respiratory depression. Our team has developed a novel regional analgesia technique, called Pectoralis-Intercostal-Rectus Sheath (PIRS) block, which promises to avoid the shortcomings of current analgesic protocols and provide superior post-operative analgesia. Preliminary results from an observational study conducted by our Group showed that PIRS block significantly reduces the requirement for opioid and anti-emetic drugs, as well as the length of hospital stay, compared to current analgesic practice. More importantly, among patients who received this intervention, those who were followed up after discharge reported no pain at 6-12 months. Evidence from a randomised controlled trial is needed to demonstrate the effectiveness of this technique in reducing the incidence of CPSP. Aims and Objectives To assess the feasibility of carrying out a larger randomised controlled trial, ORIGIN-2, aimed at investigating the effectiveness of PIRS block in reducing the incidence of CPSP, compared to current routine analgesic practice. Research Plan Design: A prospective, randomised-controlled, parallel, 4-site pilot trial with treatment allocation concealment. Setting: Queen Elizabeth Hospital (Birmingham), Royal Papworth Hospital (Cambridge), Manchester University Hospitals, Harefield Hospital (London). Population: All patients older than 15 year of age and undergoing elective CABG. Exclusion criteria: patient refusal; contraindication to regional techniques (e.g. known allergy to local anaesthetics); infection near the proposed puncture site; coagulation disorders; pregnancy; surgery for combined CABG and valve surgery; emergency cardiac surgery; previous sternotomy within 30 days; inability to comply with the completion of the study questionnaires. Intervention: PIRS and saphenous nerve blocks. Comparator: Current analgesic practice (opiate-based and nurse-led analgesia) Primary outcome: feasibility of successfully training senior anaesthetists to perform PIRS block, as measured by the rate of anaesthetists certified as competent to perform the intervention following a robust training program. Secondary outcomes: patient recruitment and attrition rates; time taken to collect study outcome data, such as scores on the Brief Pain Inventory, the Neuropathic Pain Scale, the Hospital Anxiety and Depression Scale, EQ-5D-5L, and Coronary Revascularisation Outcome Questionnaire; completeness and acceptability of these measurements at baseline, 3 and 6-month post-randomisation; willingness of surgeons and anaesthetists to participate to the trial. Timelines for delivery 24 months

Lay abstract: Cardiovascular disease (CVD) is the most common, deadly and costly disease for NHS. In the UK, there are around 7 million adults living with CVD causing 25% of all deaths with the total cost over &pound;18 billion. Coronary Artery Bypass Grafting (CABG) surgery remains a crucial surgical intervention for prevention of heart attack in patients with CVD. CABG through the middle of the chest (sternotomy) with a leg graft causes pain postoperatively, with more than 50% developing chronic post-sternotomy pain (CPSP) which can last months or years. The pain interferes with patients daily life resulting in a significant decrease in their physical, mental and social health. Half of them suffer from neuropathic pain that can be severe and debilitating, leading to more frequent GP visits, longer sick leave or even unemployment. CPSP will remain a significant health care and economic burden following UK aging and diabetic population accelerating. The current practice of cardiac anaesthesia uses intravenous opioids as the mainstay of perioperative pain management that hinders postoperative enhanced recovery from nausea, vomiting, delirium and respiratory depression. Blocking the central nerve, long regarded as &ldquo;the gold standard&rdquo; has the potential for causing devastating complications in cardiac surgery. Our team have developed a novel technique which eliminates the use of opiods and provides pain free management by blocking the bilateral nerve to numb both sides of chest and continuing the use of local anaesthetic post-operatively for up to 5 days plus using single nerve block to numb the leg. At the Queen Elizabeth cardiothoracic centre, 31 cardiac patients who received this technique, compared with hospital data of same case-mix, had a 2-fold reduction in opioids and anti-sickness requirement, 2 day reduction in length of hospital stay. More importantly, 7 out of 7 patients followed up reported no pain after 6 months. These findings suggest this technique could be a promising solution to CPSP to benefit the NHS and the patients. We presented our proposal to the PPI, cardiac anaesthetists, surgeons who were greatly supportive. We therefore seek to investigate clinical and cost effectiveness of this new technique on CPSP in a definitive randomised controlled trial (RCT). Our team is uniquely placed to run this critically important project. However there are certain aspects of the study that need further clarification, e.g. patients willingness being randomised to this technique vs. usual care, the training to be arranged or potential barriers for recruiting patients into a large trial etc. This feasibility study aims to answer these questions so that the subsequent trial has the best chance of gaining funding and being successful. The PPI co-applicant actively contributed to the development of the Plain English Summary and will continue her active role throughout this study.

Research activity codes: 6.4 SURGERY
Health categories: CARDIOVASCULAR