Lipid emulsion therapy during management of the critically-ill poisoned patient: a prospective cohort study

Background: Despite conflicting data, intravenous lipid emulsion has emerged as a potential antidote. The “lipid sink” theory suggests that following intravenous administration of lipid, lipophilic drugs are sequestered in the vascular compartment, thereby reducing their tissue concentrations. This study sought to determine if survival is associated with the intoxicant’s degree of lipophilicity. Methods: We reviewed all cases in the Toxicology Investigators Consortium’s lipid sub-registry between May 2012 through December 2018. Information collected included demographics, exposure circumstances, clinical course, management, disposition, and outcome. The primary outcome was survival after lipid emulsion therapy. Survival was stratified by the log of the intoxicant’s octanol-water partition coefficient. We also assessed the association between intoxicant lipophilicity and an increase in systolic blood pressure after lipid emulsion administration. Results: We identified 134 patients, including 81 (60.4%) females. The median age was 40 years (interquartile range 21-75). One hundred and eight (80.6%) patients survived, including 45 (33.6%) with cardiac arrest during their intoxication. Eighty-two (61.2%) were hypotensive, and 98 (73.1%) received mechanical ventilation. There was no relationship between survival and the log of the partition coefficient of the intoxicant on linear analysis (P = 0.89) or polynomial model (P = 0.10). Systolic blood pressure increased in both groups. The median (interquartile range) systolic blood pressure before lipid administration was 68 (60-78) mmHg for those intoxicants with a log partition coefficient < 3.6 compared with 89 (76-104) mmHg after lipid administration. Among those drugs with a log partition coefficient > 3.6, the median (interquartile range) was 69 (60-84) mmHg before lipid and 89 (80-96) mmHg after lipid administration. Conclusion: Most patients in this cohort survived. Lipophilicity was not correlated with survival or the observed changes in blood pressure. The study did not address the efficacy of lipid emulsion.