USG PECS vs LIA for Breast Cancer Surgery

Breast cancer is the commonest cancer in UK for which women undergo surgery. Pain relief for breast surgery may be either opioid/morphine based or regional or local anesthetic technique based. Both have specific advantages and disadvantages. Regional anesthesia is known to suppress the stress response to surgery by blocking noxious afferent neural input into the central nervous system. Locoregional anesthetic techniques offer excellent pain relief without the disadvantages of morphine.These include thoracic epidural anesthesia, paravertebral block, intercostal blocks and local anesthetic infiltration of the wound. More recently, a novel ultrasound guided interfascial nerve block technique the 'Pecs block' was proposed by Blanco et al which provides an alternative method of providing postoperative analgesia for breast surgery.There is also evidence, albeit limited to support use of local anesthetic infiltration in breast surgery, which is widely used for analgesia. Currently, there are no large randomised control trials to prove the safety and efficacy of ultrasound guided Pecs blocks in breast surgery. Also, wound infiltration with local anesthetic is practiced widely and to date, there has been no study comparing local anesthetic wound infiltration with USG pecs blocks. On this background, we intend to perform a prospective randomised double blinded trial to evaluate the efficacy and safety of ultrasound guided Pecs blocks for breast surgery by comparing it local anesthetic wound infiltration. This is a single-centre, prospective, double blinded randomised case control interventional study. The study plans to enroll 110 participants. Patients will be randomly allocated to either group X or Y using computer generated numbers. Standard monitoring as per AAGBI (Association of anesthetists of Great Britain and Ireland) guidelines will be instituted as per clinical requirement. All patients will be anaesthetized using total intravenous anesthesia using TCI (target controlled infusions) of propofol and remifentanil. Intraoperatively, propofol and remifentanil infusions shall be titrated by the anesthetist to maintain adequate depth of anesthesia and analgesia. Following induction of anesthesia and before surgical incision, all patients will receive USG modified Pecs 2 blocks as described by Blanco et al with 30 mls of pharmacy prepared Drug A (containing active drug that is 0.25% levobupivacaine) or Drug P (containing placebo 0.9% NaCl), labelled "PRE" (pre-surgery) respectively based on the group to which they are allocated. At the end of surgery, the surgeon shall infiltrate the wound with 30 mls of Drug P or Drug A respectively, labelled "POST". (post-surgery) The anesthetist and surgeon doing the interventions will both be blinded as to the pharmacological contents of the drug. This will be done as previously mentioned with pharmacy labelling the drugs as "PRE" used for USG pecs block and "POST" for wound infiltration. Also the observer, in this case the recovery nurse who will be titrating analgesia in the immediate postoperative period shall be blinded as to what group the patient belongs to. Intraoperative analgesia will be provided by TCI remifentanil. It shall be supplemented in all patients with intravenous paracetamol and parecoxib as part of a multimodal analgesic technique. Following completion of surgery, the patients will be recovered by two dedicated recovery nurses. The nurses will titrate intravenous morphine in the immediate postoperative period aiming to keep the NRS (Numerical rating Scale) pain scores below 1. Observations will be made in the intraoperative \& postoperative period looking at relevant outcome measures. Patients shall be followed up at 1h, 6h and 24 hrs to collect primary outcome measures. Secondary outcomes will be collected by telephonic follow up at 6 months and 12 month intervals following surgery.