Suprascapular block with infraclavicular block in shoulder surgery

Combined suprascapular and infraclavicular regional block Written informed consent obtained. Patients will be randomized to one of the two groups (Group I or Group C). Blocks and anaesthesia will be performed prior to commencement of shoulder surgery when the surgeon is not in the room. All patients will receive pre medication with 1.5g of oral paracetamol (1g if <50kg), then enter theatre and be positioned on shoulder table. Standard anaesthetic monitoring will be attached (non invasive blood pressure (NIBP), electrocardiography (ECG), pulse oximetry). IV access will be obtained in the contralateral upper limb. 50mcg fentanyl administered IV along with TIVA (Marsh model) target plasma concentration 0.5-1mcg/ml. Intra operative tramadol will be avoided. Head turned to contralateral side. Chlorhexidine/alcohol skin prep from mastoid to acromion, nipple and midline anteriorly, and above spine of scapula posteriorly (skin prep will be the same in both groups to maintain surgeon blinding). Ultrasound guidance used to identify interscalene landmarks (C5/6 roots, anterior and middle scalene muscles). Group I: Place interscalene catheter under ultrasound guidance (high frequence linear probe) out of plane with 51mm eCath. Catheter tip aimed beside the C5/6 root, adjacent to middle scalene. Inject 20ml Ropivacaine 0.375%. Readjust needle tip as required to obtain adequate spread of LA. Secure catheter with Friar’s balsam, tegaderm dressing and medipore tape. Induction of general anaesthesia and positioning for surgery (see details below). Make small skin punctures with 18G needle as for infraclavicular and suprascapular block. At end of procedure operating surgeon infiltrates up to 20ml 0.25% plain bupivacaine around the port sites. Group C: Place interscalene catheter as above using 20ml NaCl 0.9% instead of ropivicaine and position catheter tip as above to obtain adequate spread. Secure catheter with Friar’s balsam, tegaderm dressing and medipore tape. Induction of general anaesthesia (see details below). Site infraclavicular block with 100mm 18G sonoplex needle. In plane approach. Aim to position tip inferior to subclavian artery. Inject 15ml 0.375% ropivacaine to surround subclavian artery. Position patient in semi sitting position and scan suprascapular fossa. Place needle tip on floor of suprascapular fossa beside suprascapular artery. Inject 10ml 0.375% Ropivacaine just above floor of suprascapular fossa. At end of procedure operating surgeon infiltrates up to 20ml 0.25% plain marcain around the port sites. General Anaesthesia Induction: 100% Oxygen via facemask. Increase TCI Propofol to adequate level as judged by anaesthetist and depth of anaesthesia monitoring. (usually 3-6mcg/ml). Commence Remifentanil infusion (TCI Minto effect site concentration 2ng/ml) Insert supraglottic airway device. PCV with PEEP 5cm H20 to obtain tidal volume of 6ml/kg and ETCO2 40-50mmHg. Use phenylephrine as required to maintain MAP > 80% of baseline on the ward. Use glycopyrrolate/atropine as required to maintain HR > 40 Parecoxib 40mg IV given to all patients prior to skin incision. Additional monitoring – temperature (nasopharyngeal) and Bispectral Index(BIS)/Entropy to maintain < 60.