Full thickness endotracheal tube defect resulting in an anaesthetic circuit leak

Background: Loss of endotracheal tube (ETT) integrity secondary to dental damage is reported in the human literature. Objective: To describe this problem in equine anaesthesia. Study design: Case report. Clinical summary: An 18-year-old Standardbred gelding presented out of hours with colic signs. Findings on clinical examination and pain refractory to analgesia meant that exploratory laparotomy was elected for. Prior to general anaesthesia (GA) leak testing of the anaesthetic machine was performed and the pilot balloon of the endotracheal tube (ETT) was inflated to confirm cuff integrity. Intermittent-positive pressure ventilation (IPPV) was initiated immediately following placement in dorsal recumbency and connection to the anaesthetic machine. During the inspiratory phase of IPPV, a loud gas leak was audible from the oropharynx and minimal thoracic excursion was observed, with repeated inflations of the ETT cuff unsuccessful at abolishing the leak. Due to suspicion of a defect within the silicone ETT itself, a support arm was used to abolish the curvature of the ETT, maintaining it in a straighter plane. This intervention abolished the leak allowing effective IPPV. After completion of GA, a close inspection of the ETT revealed a full-thickness laceration, thought to be a result of dental damage at an earlier date. Main limitations: A single case is described. Conclusions: This report emphasises the importance of thorough inspection of the ETT prior to use to effectively secure the airway and enable IPPV provision in critical cases.