Test Catalog

Test ID: BFBL    
Bilirubin, Body Fluid

Useful For Suggests clinical disorders or settings where the test may be helpful

Evaluation of peritoneal fluid or abdominal drain fluid as a screening test for bile leakage


May aid in the distinction between a transudative and an exudative pleural effusion

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Peritoneal fluid:

Bilirubin is typically measured in peritoneal fluid of patients with suspected bile duct leak or gallbladder perforation as a screening test prior to imaging or cholescintigraphy. If the value is higher than that of serum and is greater than 6 mg/dL, and the ascitic fluid amylase is not elevated (indicating upper intestinal perforation), it can be assumed that the gallbladder has perforated into the peritoneum (choleperitoneum) and/or bowel or biliary perforation has occurred.(1) Furthermore, biliary leakage after laparoscopic cholecystectomy is the most common post-operative complication.(2) While endoscopy is a beneficial first-line treatment for the management of bile leaks there often are logistical issues which hinder the procedure from being performed rapidly. Post-cholecystectomy patients generally have a drain in place (particularly a Jackson Pratt or JP drain) and may undergo bilirubin testing on the drain fluid as an objective assessment of a bile leak. A body fluid/serum bilirubin ratio of greater than 5 in a JP drain fluid is highly sensitive and specific for bile leak.(3)


Pleural fluid:

Measurement of bilirubin in pleural fluid has been investigated to aid in the differentiation of transudative and exudative effusions in pursuit of more specific biomarkers than traditional light criteria measuring total protein and lactate dehydrogenase. Bilirubin values tend to be higher in exudates than in transudates, although there is some overlap between groups which limits the usefulness of its measure.(4)


Other fluids:

Determination of body fluid bilirubin concentration can aid in the distinction between a transudative and an exudative fluid or identify the presence of bile in other fluid compartments.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

An interpretive report will be provided.

Interpretation Provides information to assist in interpretation of the test results

Bilirubin may be measured in other fluids although the decision limits are not well defined in fluids other than pleural fluid. Fluid to serum bilirubin ratios are expected to be less than or equal to 1.0 and should be interpreted in conjunction with other clinical findings.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Bilirubin is photosensitive. Failure to protect from light may cause decreased results.


In very rare cases, gammopathy, in particular type IgM (Waldenstrom macroglobulinemia), may cause unreliable results.


Cyanokit (Hydroxocobalamin) may cause false low results.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Runyon BA: Ascitic fluid bilirubin concentration as a key to choleperitoneum. J Clin Gastroenterol. 1987 Oct;9(5):543-545

2. Koch M, Garden OJ, Padbury R, et al: Bile leakage after hepatobiliary and pancreatic surgery: a definition and grading of severity by the International Study Group of Liver Surgery. Surgery 2011. May;149(5):680-688. doi: 10.1016/j.surg.2010.12.002

3. Darwin P, Goldberg E, Uradomo L: Jackson Pratt drain fluid-to-serum bilirubin concentration ratio for the diagnosis of bile leaks. Gastrointest Endosc. 2010 Jan;71(1):99-104. doi: 10.1016/j.gie.2009.08.015

4. Metintas M, Alatas O, Alatas F, Colak O, Ozdemir N, Erginel S: Comparative analysis of biochemical parameters for differentiation of pleural exudates from transudates Light's criteria, cholesterol, bilirubin, albumin gradient, alkaline phosphatase, creatine kinase, and uric acid. Clin Chim Acta. 1997 Aug 29;264(2):149-162. doi: 10.1016/s0009-8981(97)00091-0