Biliary Sludge

Biliary sludge is a suspension of cholesterol crystals, calcium bilirubinate granules, mucin and cellular debris in bile, visualised as low-amplitude echoes that layer without acoustic shadow.

• It is a precursor of gallstones and a cause of biliary colic, cholecystitis, cholangitis and acute pancreatitis (unexplained recurrent acute pancreatitis).
• Risk factors: pregnancy, rapid weight loss, bariatric surgery, prolonged fasting or parenteral nutrition, critical illness, ceftriaxone, octreotide, ciclosporin, bone marrow or solid organ transplant, spinal cord injury, haemolytic anaemia, hypertriglyceridaemia.
• It resolves in many patients when the risk factor is removed (pregnancy, weight loss, ceftriaxone).

Most are asymptomatic; incidental finding on ultrasound.

• Biliary colic (epigastric or right upper quadrant pain after fatty meals, lasting 30 minutes to hours), nausea, vomiting; acute cholecystitis, cholangitis, or pancreatitis.
• Differential diagnosis: gallstones, polyps, gallbladder carcinoma, adenomyomatosis, hepatitis, peptic ulcer disease, functional gallbladder disorder, sphincter of Oddi disorder.
• Complications: gallstone formation (10 to 15 percent in some risk groups), acute pancreatitis, acute cholecystitis, acalculous cholecystitis in critical illness, cholangitis and biliary obstruction.

Transabdominal ultrasound shows mobile low-level echoes layering dependently in the gallbladder, shifting with position, with no acoustic shadow.

• Endoscopic ultrasound is more sensitive (detects microlithiasis and sludge in idiopathic pancreatitis).
• Liver profile, lipase, amylase and triglycerides if pancreatitis; full blood count and CRP if infection.
• Repeat ultrasound in 4 to 6 weeks after correcting the risk factor.
• MRCP or CT when common bile duct involvement is suspected.

Supportive

• Asymptomatic: observation, no treatment.
• Address the risk factor: stop or switch ceftriaxone and octreotide if possible, restart enteral feeding early in the critically ill, gradual weight loss (below 1.5 kg weekly), avoid prolonged fasting.
• Dietary advice: low fat diet during pain episodes.

Pharmacological

• Prevention in rapid weight loss or after bariatric surgery: ursodeoxycholic acid 500 to 600 mg daily in divided doses for 6 months.
• Symptomatic sludge when surgery is delayed: ursodeoxycholic acid 8 to 10 mg/kg/day in 2 to 3 divided doses for 3 to 6 months.
• Analgesia during colic: diclofenac 75 mg IM or 50 mg orally, hyoscine butylbromide 20 mg IV or orally, paracetamol 1 g every 6 hours; opioid (pethidine or morphine 2.5 to 5 mg IV) for severe pain.
• Acute pancreatitis: fluid resuscitation (Ringer lactate 250 to 500 mL/h in first 24 hours, guided by response), analgesia, early enteral feeding.

Procedures

• Laparoscopic cholecystectomy for symptomatic sludge with recurrent biliary pain or pancreatitis.
• Endoscopic retrograde cholangiopancreatography with sphincterotomy for biliary pancreatitis or choledocholithiasis in those unfit for surgery.

Special groups: pregnancy (conservative care; sludge often resolves postpartum), critical illness (acalculous cholecystitis surveillance), patients taking ceftriaxone (hydration and drug withdrawal).

Red flags: fever with jaundice (cholangitis), pancreatitis, persistent pain, gallbladder wall thickening, peritonism.

Follow-up: repeat ultrasound at 3 months; counsel on diet; consider cholecystectomy if recurrent.