Clinical Information

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) or either 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 [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.