Local anaesthesia systemic toxicity (LAST) in a pregnant woman following lignocaine administration

Local anaesthesia systemic toxicity (LAST) is a rare, life-threatening reaction that occurs when local anaesthetic concentrations reach toxic levels. This report discusses a pregnant patient who developed LAST after lignocaine injection postpartum, which initially resembled a drug hypersensitivity reaction.

A 37-year-old, healthy, non-atopic patient at 41 weeks’ gestation was admitted for her first delivery in 2020. Due to incomplete afterbirth, combined spinal and epidural anaesthesia was administered. Shortly after that, the patient developed symptoms of LAST, including a metallic taste, agitation, hypotension, tachycardia, weakness, and muscle tremors. Immediate interventions, including oxygen therapy, hydrocortisone, ephedrine, Intralipid, and intravenous fluids, led to symptom improvement within 30 minutes. During her second pregnancy at 37 weeks, the patient sought an allergy consultation regarding local anaesthesia safety. After consulting the anaesthesiology team, skin prick, intradermal tests, and subcutaneous provocation with bupivacaine were performed. All tests were negative, excluding hypersensitivity and allowing the safe use of bupivacaine for potential regional anaesthesia during delivery.

As the number of caesarean sections rises and the use of local anaesthesia during vaginal deliveries becomes more common, managing and treating LAST in pregnant women is becoming an increasingly significant concern.