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Background and Aims The use of intrathecal or rescue opioids is common in total hip arthroplasty (THA). However in patients with severe respiratory disease the effects of opioids may not be tolerated. Several case series have described the use of liposomal bupivacaine (Exparel) in local infiltration in an opioid-sparing technique for THA. However we describe a novel approach to managing such patients using ultrasound guided Exparel nerve group blocks and sedation with remimazolam.

Methods A 69 year old gentleman underwent a right THA with a history of severe COPD, obstructive sleep apnoea and bronchiectasis with limited exercise tolerance. The anaesthetic technique involved a plain intrathecal injection of 3.0ml 2% prilocaine, followed by lateral cutaneous nerve of the thigh, pericapsular nerve group (PENG) and quadratus lumborum fascial plane infiltration utilising a local anesthetic admixture comprising of 20ml

13.3mg/ml Exparel, 40ml 0.25% levobupivacaine and 20ml normal saline. Intraoperatively the patient was managed with a total of 20mg of remimazolam over 2 hours, with 1g paracetamol, 2.5g magnesium sulphate and 400mg ibuprofen given intravenously.

Results The patient underwent THA with no perioperative respiratory or cardiovascular complications, and was monitored in HDU overnight. Analgesia was largely controlled using regular simple analgesia (paracetamol and codeine) with with only an additional total of 100mg tramadol and 10mg oral morphine required during his 7 day inpatient stay.

Conclusions THA in a high-risk respiratory patient can be performed safely without medical complications utilising an opiate-free technique with remimazolam sedation, short-acting spinal anaesthesia and ultrasound-guided infiltration using Exparel, with reduced need for post-operative opioid analgesia.

Attachment Case report consent statement.pdf