creation date: 2025-12-24 23:51
tags: Pathologies
Acute Cholecystitis
Background
Definitions
Acute cholecystitis refers to the inflammation of the gallbladder.
Chronic cholecystitis is a term used to describe chronic inflammatory cell infiltration of the gallbladder seen on histopathology but is not typically clinically relevant.
Etiology and Pathogenesis
The most common cause of acute cholecystitis is due to cystic duct obstruction from cholelithiasis. With intermittent or mild obstruction, biliary colic may result but with persistent obstruction, the bile builds up and causes distension and inflammation/ischemia of the gallbladder.
The stagnant bile is a favourable environment for bacterial colonization which can worsens inflammation. However, not all patients with cholecystitis have infected bile.
In rarer cases, acute cholecystitis may occur without gallstones, known as acalculous cholecystitis. This typically occurs in critically ill patients and due to ischemia of the gallbladder from hypoperfusion.
Clinical Presentation
Signs & Symptoms
Typical symptoms include:
- Abdominal pain in the RUQ or epigastric regions
- Pain described as steady/constant and >6 hours
- Pain may radiate to right shoulder or back
- May be associated with fever, nausea, vomiting, anorexia
- Often associated with fatty food ingestion ≥1 hour prior
Signs include:
- Ill-appearing
- Fever
- Tachycardia
- Peritoneal inflammation signs
- Voluntary and involuntary guarding
- Positive Murphy’s sign
History & Physical Exam
Physical exam should include a complete abdominal exam.
Risk factors
Risk factors include:
- Female sex
- Obesity
- Pregnancy
- ≥40 years of age
Drastic weight loss or acute illness may elevate risk further. Additionally, family history of gallstones may increase susceptibility.
Increased RBC breakdown increases pigment accumulation in the biliary system which may predispose patient to stones.
Diagnosis
Criteria
Diagnosis of acute cholecystitis requires at least one of the following:
- Gallbladder wall thickening or edema
- Sonographic Murphy’s sign
- Failure of gallbladder to fill during cholescintigraphy (indicating blockage)
Work-up
Imaging for diagnosis
Diagnosis is typically made with abdominal ultrasound. If diagnosis is unclear, cholescintigraphy can be completed.
CT and MRCP are typically not required but may be performed to assess complications and rule out alternative diagnoses (eg. suspected choledocholithiasis).
Laboratory studies
- CBC (WBCs elevated)
- Serum lipase and amylase
- Electrolytes, creatinine
- ALT, AST
- Bilirubin, albumin
- Calcium
Differential
Biliary colic:
- Pain lasts <6 hrs
- Lack of constitutional symptoms
Acute cholangitis: - Evidence of cholestasis on laboratory testing and biliary dilation on imaging
- Can be concurrent with acute cholecystitis
Fitz-Hugh Curtis syndrome: - Acute pelvic inflammatory disease results in periherpatitis that manifests as RUQ pain
Red Flags / Complications
While symptoms may resolve within 7-10 days, acute cholecystitis have severe and frequently occurring complication which require definitive treatment.
Gangrenous cholecystitis
Most common complication of cholecystitis, especially in older patients or patients with diabetes. Increased luminal pressure compresses vessels which results in wall ischemia and necrosis.
This may be associated with sepsis-like symptoms.
Grangrene can predispose wall to gallbladder perforation which may initially appear as relief due to bile spilling into the peritoneum. However, this leads to generalized peritonitis, sepsis, and is associated with high mortality.
Emphysematous cholecystitis
If infection of the gallbladder wall is by gas-forming organisms such as Clostrifium perfringens.
Cholecystoenteric fistula
Perforation of the gallbladder directly into the intestinal lumen can form if long standing pressure causes necrosis. Passage of a gallstone larger than 2.5 cm through the fistula may lead to mechanical bowel obstruction, typically at the narrowest part of the terminal ileum resulting in gallstone ileus.
Management
General Management
Patients should be admitted to hospital and provided with supportive care:
- IV fluids
- Correction of electrolyte abnormalities
- Pain control
- IV antibiotics
- NPO
Pain control
Pain control is typically by NSAIDs or opioids.
- Ketorolac
- Opioid (morphine, hydromorphone, meperidine)
Antibiotics
Broad-spectrum IV antibiotics are required for complicated cholecystitis and recommended for uncomplicated disease. Therapy should continue until the gallbladder is removed or the cholecystitis clinically resolves.
The choice of antibiotics varies by local practice and patient risk.
Surgical Treatment
In a minority of patients, emergency cholecystectomy may be indicated such as in the presence of complications or progressive symptoms (eg. high fever, hemodynamic instability, intractable pain).
Percutaneous cholecystostomy may be necessary to drain infected bile in critically ill settings.