Alfaxalone–dexmedetomidine–isoflurane partial intravenous anaesthesia in combination with scalp block in a cat undergoing craniectomy for meningioma excision

A 12-year-old, spayed, female domestic shorthair cat was presented for hyporexia, weakness and right circling. Magnetic resonance imaging revealed two space-occupying lesions consistent with the diagnosis of meningioma. Surgical excision of one mass was planned via craniectomy. Premedication consisted of intramuscular methadone, midazolam and dexmedetomidine, and anaesthesia was induced intravenously with alfaxalone and fentanyl. Partial intravenous anaesthesia was maintained with isoflurane and constant rate infusions of alfaxalone (8 mg/kg/h) and dexmedetomidine (0.5 µg/kg/h). Maropitant was administered for antiemetic prophylaxis. A scalp block targeting the supraorbital, zygomaticotemporal and auriculotemporal nerves was performed preoperatively with ropivacaine, and intraoperative rescue analgesia was unnecessary. Pain was assessed hourly using the short-form Glasgow Feline Composite Measure Pain Scale, and rescue methadone was required 7 hours after block completion. This case describes the implementation of a scalp block and partial intravenous anaesthesia protocol for craniectomy and cranioplasty in a cat undergoing meningioma excision.