Description: Bile acids are produced by the liver and stored in the gallbladder; they are released into the small intestine to aid in the digestion and absorption of fats. Abnormal levels of bile acids in the blood or urine can indicate liver or gastrointestinal dysfunction.
Feasibility/Equipment: Measured via blood test. Assay may not be available in all units.
Scoring information: Serum bile acids levels significantly increased in critical care patients compared to healthy controls however reference values for clinical significance not fully established.
Cost: High; not routinely measured in clinical practice.
Evidence: Bile acid signalling as a mechanism of GI dysfunction has not been studied in adult critically ill patients, but increased levels of bile acids in circulation are associated with adverse outcome. Intrahepatic cholestasis of the critically ill is a consequence of alterations of bile acid signalling and transportation at the hepatocellular level. Although the clinical association of cholestasis and inflammation are established, recent studies demonstrated that alterations of hepatic transport and metabolism occur early after ICU admission. In case of malabsorption, the reabsorption of bile acids is reduced and the negative feedback for hepatic bile acid synthesis is inhibited.
Accuracy / measurement properties: Serum bile acids levels significantly increased in critical care patients compared to healthy controls however reference values for clinical significance are not fully established.
References:
Reintam Blaser, A., Preiser, JC., Fruhwald, S. et al. Gastrointestinal dysfunction in the critically ill: a systematic scoping review and research agenda proposed by the Section of Metabolism, Endocrinology and Nutrition of the European Society of Intensive Care Medicine. Crit Care 24, 224 (2020).
Horvatits T, Drolz A, Rutter K, Roedl K, Langouche L, Van den Berghe G, et al. Circulating bile acids predict outcome in critically ill patients. Ann Intensive Care. 2017;7:48.
Xiao YT, Cao Y, Zhou KJ, Lu LN, Cai W. Altered systemic bile acid homeostasis contributes to liver disease in pediatric patients with intestinal failure. Sci Rep. 2016;6:39264.