Prospective cohort study of rotational thromboelastometry in established biliary obstruction: dispelling the myth of auto-anticoagulation.

BACKGROUND

Patients with obstructive jaundice are conventionally described as hypocoagulable due to vitamin K malabsorption. However, associated underlying malignancy and synthetic liver dysfunction are mediators of hypercoagulability. The actual effect of biliary obstruction on the coagulation profile is not well characterised. This study aimed to define the coagulation status of patients with established biliary obstruction using rotational thromboelastometry (ROTEM).

METHODS

This prospective cohort study, conducted in an Australian metropolitan hospital, included patients with a total bilirubin level of >150 umol/L and biliary obstruction on imaging. The primary outcome was the coagulation profile assessed using ROTEM.

RESULTS

20 patients were included (median age 74.5 years), 15 were male and 17 had a malignant cause for biliary obstruction. The median bilirubin level was 209 umol/L (IQR: 175.0 umol/L - 255.8 umol/L). On ROTEM, all patients had normal or reduced clot formation times, and normal or increased maximum clot firmness. This confirmed all patients had a normal or hypercoagulable clotting profile, and none were auto-anticoagulated. Vitamin K administration before ROTEM did not vary the coagulation profile.

DISCUSSION: Patients with established biliary obstruction and jaundice, predominantly due to malignancy, were normo or hypercoagulable. The belief that obstructive jaundice is associated with a hypocoagulable state should be questioned.