Cardiopulmonary arrest and resuscitation following an extradural injection in a normovolemic dog

Abstract

Objective – To describe general anesthesia and successful resuscitation of a dog developing asystole and apnea during extradural injection of local anesthetic and an opioid. Case Summary – A Beagle with a ruptured cranial cruciate was premedicated with acepromazine and methadone. Anesthesia was induced with propofol and, after endotracheal intubation, maintained using isoflurane in oxygen. During extradural injection of a mixture of lidocaine, bupivacaine, and morphine the dog developed apnea and asystole. Cardiopulmonary cerebral resuscitation was started promptly and the dog was successfully resuscitated. New Information Provided – Asystole and apnea are possible serious side effects of extradural anesthesia in dogs. With adequate monitoring and early detection successful resuscitation is possible.

Ventricular fibrillation in a dog with refractory hyperkalaemia due to uroabdomen following extradural anaesthesia

“…This progressed to asystole following extradural injection within 20 seconds up to 2 minutes later in the other veterinary reports of post‐epidural CPA. It may be significant that the timing of arrest corresponded with the onset of lidocaine administered in three of these reports and with levobupivacaine in the presented case 3,7–9 …”

“…It may be significant that the timing of arrest corresponded with the onset of lidocaine administered in three of these reports and with levobupivacaine in the presented case. 3,[7][8][9] Spread of extradural local anaesthetic agents further cranial to block cardiac accelerator nerves arising from T1-T4 exacerbates cardiac depression. Migration may have been potentiated by increased IAP in this case, mediated by a reduction in extradural space volume due to enlarged venous plexuses.…”

“…5 The volume and speed of administration was appropriate here and in all previous veterinary reports of post-epidural arrest. 3,[7][8][9] Vagolytic therapy and intravenous fluid boluses may therefore be key interventions in the treatment of bradycardia or CPA following extradural local anaesthetic, alongside RECOVER guidelines. Some authors in human medicine advocate prophylactic volume loading to counter a vagal, relative hypovolaemia.…”

“…3 Notably, arrest secondary to neuraxial local anaesthesia is uncommon in veterinary medicine, having only been reported in dogs four times previously. 3,[7][8][9] It is better described in human medicine with a cited incidence of one in 1600-250,000 cases. 6 Delayed respiratory arrest has also been observed subsequent to extradural or intrathecal administration of opioids in humans and an alpaca.…”

“…Notably, arrest secondary to neuraxial local anaesthesia is uncommon in veterinary medicine, having only been reported in dogs four times previously 3,7–9 . It is better described in human medicine with a cited incidence of one in 1600–250,000 cases 6 .…”