Pulmonary and laryngeal oedema before induction of anaesthesia in a sheep

Abstract

This case report describes the anaesthesia of a ram undergoing an exploratory laparotomy, which suffered from respiratory distress during the perioperative period. On the morning of surgery, the animal presented with oedematous ears, most likely caused by a tight-fitting muzzle that had been used for preoperative fasting. After sedation, a mild stridor was heard. During endotracheal intubation, a swollen larynx was observed, and a frothy discharge emerged through the endotracheal tube after placement. Most likely, the tight muzzle caused a partial obstruction of the nostrils, increasing the respiratory effort and causing an increase in the pressure gradient, which provoked laryngeal and pulmonary oedema. Treatment consisted of repeated suctioning of fluid from the endotracheal tube, furosemide, dexamethasone, mechanical ventilation with 100% oxygen during anaesthesia and oxygen supplementation during recovery. Despite moderately low arterial oxygen tension during anaesthesia, the animal recovered uneventfully and did not show further signs of respiratory distress.