Seizures and prolonged recovery from general anaesthesia in a horse with guttural pouch mycosis undergoing bilateral arterial coil embolisation

Abstract

An 11-year-old Holstein mare was referred after profuse bilateral epistaxis due to fungal plaques. Clinical evaluation was unremarkable except for mild tachycardia. General anaesthesia was induced for coil embolisation of the left internal carotid artery, right external carotid and maxillary arteries. Under anaesthesia, cardiorespiratory stability was ensured, and six coils were deployed under fluoroscopy, whereas three previously deployed coils were found. During recovery from anaesthesia, generalised seizures, fast horizontal nystagmus and a breath-holding breathing pattern were evident. Diazepam and medetomidine were administered, but the seizures resumed shortly after. After the administration of hypertonic saline solution and hydrocortisone, the seizures ceased. However, the horse remained unresponsive for 3 hours despite supportive care consisting of oxygen, glucose, fluid therapy and warming. Although a poor prognosis was presumed, the horse recovered after one attempt, 180 minutes after isoflurane cessation. The present case report highlights the importance of adequate support during recovery from anaesthesia.