Liver-type fatty acid-binding protein: A hemodynamic index during extracorporeal membrane oxygenation

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support is often essential for patients who experienced cardiac arrest. Although lactate levels have been considered during hemodynamic management in such cases, some patients with normal hemodynamics and oxygenation exhibit elevated lactate levels due to the influence of underlying diseases such as sepsis and malignant tumors. In contrast, urinary liver-type fatty acid-binding protein (L-FABP), a biomarker of renal ischemia and acute systemic ischemic injury, is less likely to be affected by these factors, indicating that it may be a more sensitive hemodynamic indicator than lactate. However, no previous reports have discussed the use of L-FABP during VA-ECMO management of patients with severe ischemic injury after cardiac arrest. Herein, we discuss a case in which L-FABP measurements were used to manage a 46-year-old male patient receiving VA-ECMO support. His mean blood pressure was ≥ 75 mmHg for the first 24 h after the initiation of VA-ECMO, and he experienced a rapid decrease in both L-FABP and lactate levels, the patterns of which were similar. Weaning him off VA-ECMO was eventually successful based on the combination of mechanical settings, echocardiographic parameters, and hemodynamic indices. The current case suggests that measurement of L-FABP levels can aid in selecting the target mean blood pressure, determining whether to increase or decrease the flow rate of VA-ECMO, and determining whether weaning from VA-ECMO is appropriate. As L-FABP levels can be measured in approximately 10 minutes, they may have substantial clinical value when rapid decision-making is required.