Pretreatment With an Intravenous Lipid Emulsion Increases Plasma Eicosapentanoic Acid and Downregulates Leukotriene B4, Procalcitonin,and Lymphocyte Concentrations After Open Heart Surgery in Infants

Background: The effect of providing a lipid emulsion containing medium‐chain triglyceride (MCT), soybean oil, and fish oil in critically ill infants is not widely studied. This study investigated lipid emulsion effects on plasma phospholipids and immune biomarkers. Materials and Methods: Thirty‐two infants undergoing cardiopulmonary bypass (CPB) and dependent on parenteral nutrition (PN) were randomized to receive either soybean oil (control, n = 16) or a 50:40:10 mixture of MCT, soybean oil, and fish oil (treatment, n = 16). PN was administered for 3 days preoperatively and 10 days postoperatively. Fatty acids, procalcitonin (PCT), leukotriene B₄ (LTB₄), and lymphocytes were quantified at baseline, before surgery, and days 1, 7 and 10 after surgery. Results: PCT was significantly lower in the treatment vs control group 1 day postoperatively (P = .01). The treatment group exhibited a lower ω‐6 to ω‐3 ratio (P = .0001) and a higher ω‐3 concentration at all postoperative study periods (P = .001). Treatment resulted in higher (P < .05) plasma phospholipid eicosapentaenoic acid (EPA) on days 7 and 10, while α‐linolenic acid, arachidonic acid, and docosahexaenoic acid remained constant. An increase in plasma phospholipid EPA concentration was associated with a decrease in plasma phospholipid LTB₄ concentration (P < .05). On postoperative day 10, treatment infants with high Pediatric Risk of Mortality III scores exhibited a 45% lower lymphocyte concentration (P < .05). Conclusion: These findings suggest that treating infants undergoing CPB with a lipid emulsion containing ω‐3 improves fatty acid status and results in a lower inflammatory response after surgery. Overall, this alternative ω‐3–enriched lipid emulsion may benefit clinical outcomes of critically ill infants after cardiac surgery.