Gall-bladder sludge: lessons from ceftriaxone.

Ceftriaxone-associated sludge has been a fascinating story. The occurrence is novel and unique. It has produced a model of gall-bladder sludge in humans. This phenomenon has taught us a great deal about biliary lipid and organic anion excretion by the liver, and the physical chemistry of calcium and calcium sensitive anions. It has added further insights into the pathophysiology of gall-bladder sludge formation. It points to a combination of a hepatic effect where the liver secretes a biochemically abnormal bile, and a gall-bladder effect which provides an environment for precipitation, in order for sludge to develop. The precipitated calcium ceftriaxone has prompted us to re-evaluate the imaging criteria for the diagnosis of gall-bladder sludge versus gallstones. Above all, the rapid onset and rapid disappearance of ceftriaxone sludge has mirrored in a compressed, encapsulated form, the natural history of gall-bladder sludge. It has reminded us that, like gallstones, biliary sludge is usually benign and asymptomatic. However just because it is smaller than gallstones does not mean it cannot cause problems. It can disappear or it can become a calcium ceftriaxone gallstone.