Case report: successful lipid resuscitation in multi-drug overdose with predominant tricyclic antidepressant toxidrome

Therapeutic use of intravenous lipid emulsion (ILE) in the arrested patient secondary to lipophilic cardiotoxin overdose is increasingly reported, with numerous documented cases of successful resuscitation outcome [1,2]. Clinical experience with lipid rescue resuscitation, coupled with a dearth of reported adverse sequelae attributable to ILE administration, has more recently seen use of lipid emulsions extend beyond that of overt cardiac arrest to instances of lesser degrees of lipophilic-toxin-induced haemodynamic instability.Few data exist, however, to guide the physician contemplating ILE use in the deteriorating patient when multiple therapeutic options remain yet untried. Specifically, the role of ILE in hemodynamic instability secondary to tricyclic antidepressant (TCA) overdose has been the subject of few pre-clinical studies [3,4]. We report a case of multi-drug overdose with predominant TCA toxicity that exhibited ongoing hypotension after systemic alkalinisation, yet before infusion of vasopressor medications, which responded to ILE loading.A 51-year-old 75-kg man with a background history of ischaemic heart disease, chronic back pain, and depression ingested amitriptyline in excess of 43 mg/kg (> 65 × 50-mg tablets) and unknown quantities of quetiapine, citalopram, metoprolol, quinapril, and aspirin in a deliberate act of self-poisoning. At ambulance arrival (time approximately 40 min after ingestion) he was agitated and poorly co-operative, with a heart rate of 160 bpm and blood pressure 100/70. En route to hospital he became unresponsive and then suffered a generalised seizure, which was terminated with 4 mg intravenous midazolam. On arrival to our tertiary care facility (time 60 min following ingestion), the Glasgow Coma Scale (GCS) score was three, temperature was 37.6°C, pupils were dilated (4 mm), heart rate was 150 beats per minute, blood pressure was 112/82 mmHg, and serum glucose 14.0 mmoll-1. A 12-lead electrocardiogram (ECG; Figure 1) revealed