Review of the effect of intravenous lipid emulsion on laboratory analyses

Abstract

Context Although the clinical use of intravenous lipid emulsion therapy for the treatment of lipophilic drug toxicity is increasing, the focus of most publications is on outcome in laboratory animals or in patients. An unintended consequence of intravenous lipid emulsion is the creation of extremely lipemic blood, which may interfere with the laboratory analysis or interpretation of common analytes. Objective The American Academy of Clinical Toxicology has established a lipid emulsion workgroup to review the evidence and produce recommendations on the use of this novel therapy for drug toxicity. The aim of this subgroup is to review the available evidence regarding the effect of intravenous lipid emulsion on common laboratory testing, which often forms the basis of the appraisal of the balance between benefits and potential adverse events. Methods We performed a comprehensive review of the literature. Relevant articles were determined based upon a predefined methodology. Package inserts of manufacturers’ assays were collected. Article inclusion required that the article met predefined inclusion criteria with the agreement of at least two members of the subgroup. Results We included thirty-six articles in the final analysis. Evaluation of the reviewed analytes revealed heterogeneity with regards to the assessment of the effect of intravenous lipid emulsion in terms of consistency and magnitude of effect across the different analytic platforms. Conclusions The measurements of a number of common analytes can be markedly affected by the lipemia produced by lipid emulsions such that they cannot always be interpreted in the way that most physicians use this information in typical clinical situations. In fact, a lack of appreciation of this effect may lead to unintentional treatment errors. Because the effect of the lipemia produced is dependent on the reagents and laboratory platform used, it would be useful for all future reports to clearly document sample handling, reagents and laboratory platform used, as well as any procedures employed to reduce the lipid content.

Keywords:

• Analytical interference
• Laboratory measurements
• Lipemia
• Lipid emulsion

Acknowledgements

Sarah Shiffert and Ellen Pak from AACT for arranging meetings and conference calls. BMG and SG are members of the Research Institute of the McGill University Health Centre. BMG and AG are representatives of the Canadian Association of Medical Biochemists.

Declaration of interest

All members of the workgroup completed a Conflict Of Interest form for AACT and received no honoraria. Webcast conferences and rooms for meetings were provided by AACT. The workgroup does not include members with a financial or academic Conflict Of Interest preventing neutral assessment of the literature reviewed (i.e. no committee member’s livelihood or academic career is depending on a grant studying lipid emulsion in poisoning).

Dr. Lavergne is the recipient of a salary support award from the Fonds de la Recherche du Québec - Santé (FRQS).

Notes

1 The AACT lipid emulsion workgroup also includes the following members: Benoit Bailey, Theodore C. Bania , Ashish Bhalla, Diane P. Calello, Ryan Chuang, Andis Graudins, Bryan Hayes, , Lotte C. G. Hoeberg , Michael Levine, Sheldon Magder, Bruno Mégarbane, Jose A. Morais, Carol Rollins, Samuel J. Stellpflug, Christine M. Stork, Simon H.L. Thomas and Alexis F. Turgeon