Thoracic transversus plane block as part of a multimodal analgesia plan in a cat undergoing sternotomy

A 12-year-old, neutered, male, domestic shorthair cat presented for investigation of acute-onset respiratory distress and cough. Computed tomography scan showed bilateral pleural effusion and dorsal elevation of the trachea compatible with a mass effect. A median sternotomy was performed. Anaesthetic protocol consisted of premedication with intravenous methadone (0.2 mg/kg), induction with alfaxalone to effect and maintenance with isoflurane in oxygen. Transversus thoracic muscle plane block was performed injecting 0.4 mL/kg of 0.25% bupivacaine per side. Fentanyl (2 mu g/kg) was administered as rescue analgesia once during surgery. The Glasgow Composite Pain Scale was assessed postoperatively. Methadone was given as rescue analgesia postoperatively when Glasgow pain score was greater than 5/20. The first administration of methadone was required at 8 hours after the transversus thoracic muscle plane block was performed. This case showed that the ultrasound-guided transversus thoracic muscle plane block is a feasible technique in feline patients as part of a multimodal analgesia plan in a cat undergoing sternotomy.