Acute cholecystitis

Acute cholecystitis describes inflammation of the gallbladder.

Pathophysiology

• develops secondary to gallstones in 90% of patients (acute calculous cholecystitis)
• the remaining 10% of cases are referred to as acalculous cholecystitis
  • typically seen in hospitalised and severely ill patients
  • multifactorial pathophysiology: gallbladder stasis, hypoperfusion, infection
  • in immunosuppressed patients it may develop secondary to Cryptosporidium or cytomegalovirus
  • associated with high morbidity and mortality rates

Features

• Right upper quadrant pain
  • May radiate to the right shoulder
• Fever and signs of systemic upset
• Murphy's sign on examination: inspiratory arrest upon palpation of the right upper quadrant
• Liver function tests are typically normal
  • Deranged LFTs may indicate Mirizzi syndrome - a gallstone impacted in the distal cystic duct causing extrinsic compression of the common bile duct

Investigation

• ultrasound is the first-line investigation of choice
• if the diagnosis remains unclear then cholescintigraphy (HIDA scan) may be used
  • technetium-labelled HIDA (hepatobiliary iminodiacetic acid) is injected IV and taken up selectively by hepatocytes and excreted into bile
  • in acute cholecystitis there is cystic duct obstruction (secondary to odema associated with inflammation or an obstructing stone) and hence the gallbladder will not be visualised

Treatment

• intravenous antibiotics
• cholecystectomy
  • NICE now recommend early laparoscopic cholecystectomy, within 1 week of diagnosis
  • previously, surgery was delayed for several weeks until the inflammation has subsided
  • pregnant women should also proceed to early laparoscopic cholecystectomy - this reduces the chances of maternal-fetal complications