Massive lignocaine overdose while on veno-arterial extracorporeal membrane oxygenation (VA ECMO)

We present the extraordinary circumstance of a female patient in her sixties who suffered a massive lignocaine overdose while undergoing treatment with Veno-Arterial Extracorporeal Membrane Oxygenation (VA ECMO) following an emergency coronary artery bypass graft (CABG). The patient was initially admitted to the Intensive Care Unit (ICU) due to unstable angina and a history of insulin-dependent type two diabetes mellitus, hypertension, hypercholesterolemia, carotid artery stenosis, and an extensive smoking history. Despite initial improvements following surgery, she experienced repeated episodes of nonsustained polymorphic ventricular tachycardia (VT) that were refractory to conventional antiarrhythmic medications. The overdose occurred due to a medication administration error, leading to the infusion of lignocaine at a rate eight times higher than intended, over the course of 36 h (total dose of 9964 mg, or 153 mg/kg). Remarkably, the patient remained haemodynamically stable throughout the overdose period, with normal sinus rhythm, requiring minimal ECMO support and no vasoactive agents. Further investigation into the pharmacokinetics of lignocaine during VA ECMO treatment suggested that the patient's unexpected stability and survival could be attributed to the adsorption of lignocaine onto the components of the ECMO circuit. This phenomenon potentially mitigated the cardiotoxic effects typically associated with such high doses of lignocaine, thus presenting an unusual but critical aspect of pharmacokinetics in the context of ECMO support. This case underscores the importance of investigating the complex interactions between medications and extracorporeal circuits, which can significantly alter drug pharmacokinetics and toxicity profiles.