Cardiopulmonary arrest following extradural analgesia and suspected secondary sympathetic blockade in a critically ill dog

Abstract An 8‐year‐old, male, entire Cocker Spaniel presented to the Queen Mother Hospital for Animals for treatment of an iatrogenic septic uroabdomen secondary to traumatic urinary catheterisation. After initial stabilisation, it underwent diagnostic imaging and definitive surgical correction comprising a cystotomy and bladder reconstruction. Post‐operatively, the patient was painful, requiring infusions of fentanyl, ketamine, lidocaine and dexmedetomidine. To reduce the doses of systemic analgesia, a morphine and bupivacaine lumbosacral epidural was performed under sedation. The patient's sepsis was considered improved before this intervention, based on normoglycaemia, normalisation of renal parameters and consistent normotension without the need for vasopressor. Approximately 15 minutes following the epidural injection, the dog underwent cardiopulmonary arrest. Cardiopulmonary resuscitation was performed, and return of spontaneous circulation was achieved, however, further cardiopulmonary arrest episodes eventually led to euthanasia. The cardiopulmonary arrest was suspected to be caused by regional sympathetic blockade from epidurally administered local anaesthetic.