Endotracheal tube obstruction due to cuff overinflation or cuff herniation in small equids: A case series

Adequate inflation of the endotracheal tube (ETT) cuff is important to avoid leakage of anaesthetic gases or aspiration of gastric contents and to allow positive pressure ventilation. However, overinflation or herniation of the cuff can cause tracheal mucosal damage and in rare cases even obstruction of the ETT. ETT obstruction due to the cuff itself may be an underrecognised phenomenon in equine practice and we aim to create awareness with this retrospective case series (n = 3). Cases identified between 2014 and 2021 with (partial) ETT obstruction due to cuff overinflation or cuff herniation at the Utrecht University Equine Clinic were selected. Anaesthesia records were examined and presented. Two cases occurred in foals and one in a pony. In each case, high airway pressure was encountered and no or minimal thoracic excursions were visible. In all three cases, cuff deflation led to immediate normalisation of ventilation parameters. When presented with an intubated patient that is difficult to ventilate and high airway pressures exist, ETT cuff overinflation or herniation should be considered as a possible cause; rapid cuff deflation should be included in algorithms for management of ventilation failure due to suspected airway obstruction.