Cholecystitis

Inflammation of the gallbladder, in the large majority of cases from cystic duct obstruction by a gallstone (calculous cholecystitis), with a smaller proportion occurring without stones (acalculous cholecystitis, typically in critically ill patients from gallbladder stasis and ischemia, carrying a higher rate of complications including gangrene and perforation).
Constant right upper quadrant or epigastric pain, often following a fatty meal, that persists beyond the transient pattern of simple biliary colic, associated with fever, nausea, and vomiting. Murphy's sign (inspiratory arrest on palpation of the right upper quadrant during deep breathing) is the classic examination finding, reflecting localized peritoneal irritation over the inflamed gallbladder. A palpable, tender gallbladder or right upper quadrant mass may be present. Jaundice is uncommon and, if present, should raise suspicion for a concurrent process such as Mirizzi syndrome (a stone impacted in the cystic duct compressing the adjacent common hepatic duct) or choledocholithiasis with cholangitis, rather than uncomplicated cholecystitis alone. Complications include gallbladder empyema, gangrene, and perforation, the latter presenting with more severe, diffuse pain and peritonism.
Abdominal ultrasound is the first-line investigation: gallstones, gallbladder wall thickening (above 3 mm), pericholecystic fluid, and a sonographic Murphy's sign together support the diagnosis with good sensitivity and specificity. FBC (leukocytosis) and CRP support the inflammatory diagnosis. LFTs are typically only mildly deranged in uncomplicated cholecystitis, with significant elevation, particularly of bilirubin, prompting reassessment for a coexisting ductal stone or Mirizzi syndrome. HIDA scan (cholescintigraphy) is reserved for cases where ultrasound is equivocal, demonstrating non-filling of the gallbladder consistent with cystic duct obstruction. CT is used to assess for complications (perforation, abscess) if the clinical picture is atypical or severe.
Differentials include biliary colic (transient pain without fever or systemic inflammatory features), cholangitis (see separate entry, ductal rather than gallbladder pathology, with jaundice as a core feature), peptic ulcer disease, acute pancreatitis, right lower lobe pneumonia, and hepatitis.
IV fluids, analgesia, antiemetics, and IV antibiotics covering gram negative enteric organisms and anaerobes (for example a second or third generation cephalosporin with metronidazole, or piperacillin-tazobactam for more severe presentations) form the initial supportive management. Early laparoscopic cholecystectomy, ideally within 24 to 72 hours of symptom onset, is the treatment of choice and is now well established as superior to a delayed interval approach, reducing overall hospital stay and complication rates without increasing operative difficulty when performed promptly by an experienced surgeon. Patients presenting late (beyond 5 to 7 days, or with a palpable phlegmon suggesting a walled off process) or those unfit for surgery are managed with continued antibiotics and either delayed interval cholecystectomy after 6 or more weeks, or percutaneous cholecystostomy for source control if the patient is deteriorating and unfit for surgery, with cholecystectomy deferred until stabilized. Acalculous cholecystitis in a critically ill patient is managed similarly, often favoring percutaneous cholecystostomy first given the typically poor surgical candidacy of this population.
Referral: general surgery for all confirmed cases, given the near universal indication for cholecystectomy either acutely or on an interval basis.

