Successful treatment of local anaesthetic toxicity using intralipid 20% emulsion following intrathoracic bupivacaine overdose in a cat

Abstract

Case summary: An 8.75-year-old male neutered Burmese cat was referred for treatment of pyothorax. The cat was responsive, cardiovascularly stable and tachypnoeic (40 breaths/min) on arrival. Medical management of pyothorax was initiated, bilateral thoracic drains were placed and thoracic lavage using aliquots of saline 0.9% was performed every 4 h. Regional analgesia was provided using 1 mg/kg of intrapleural bupivacaine divided equally between the left and right hemithoraxes every 6 h. On the second day of hospitalisation, the cat developed hypersalivation, mydriasis and tonic–clonic seizure activity 25 mins after accidental intrapleural administration of a 10 mg/kg bupivacaine overdose. Cardiovascular compromise was also noted; the cat became bradycardic (120 beats/min) and blood pressure decreased to 110 mmHg. Clinical signs resolved after administration of intravenous lipid emulsion (ILE) as an intravenous (IV) bolus (1.5 ml/kg over 5 mins), followed by a continuous rate infusion (0.25 ml/kg/min over 25 mins). Local anaesthetic intrapleural anaesthesia was discontinued. There was recrudescence of clinical signs 10 h post-overdose and repeat ILE 20% infusion was required. The cat was discharged with no ongoing complications. Relevance and novel information: Treatment of IV local anaesthetic systemic toxicity with ILE has been reported in cats. To our knowledge, this is the first reported case of intrapleural bupivacaine overdose with initial response and resolution of clinical signs followed by recrudescence and subsequent successful treatment using ILE.