Biliary colic frequently presents with epigastric or right upper quadrant pain that resolves in a few hours and is not associated with fever or leukocytosis.
Acute cholecystitis cannot be established or excluded based on history and examination alone.
Antibiotics should be administered early in ill-appearing patients when acute cholecystitis is suspected.
Acute cholecystitis can be a challenging diagnosis because the spectrum of disease ranges from biliary colic, a self-limited condition, to emphysematous cholecystitis or gallbladder perforation with sepsis. Additionally, no single historical feature, exam finding, or test result is adequate to exclude the disease in its early stages.
When a gallstone moves into the gallbladder neck, cystic duct, or common bile duct, it causes obstruction. Obstruction in turn causes an increase in luminal pressure in the gallbladder or common bile duct. In biliary colic, the obstruction is intermittent, and symptoms resolve when the blockage is relieved. If obstruction is persistent, there is a resulting increase in mucosal inflammation and irritation. Ultimately this leads to ischemia of the gallbladder wall and bacterial invasion.
Biliary colic is pain due to transient gallbladder neck blockage with a gallstone. Acute cholecystitis is inflammation of the gallbladder due to persistent obstruction from gallstones and is sometimes associated with infection. Acalculous cholecystitis accounts for 2–15% of cases of acute cholecystitis and occurs in the absence of gallstones. Acalculous cholecystitis is believed to be secondary to gallbladder ischemia and is more common in diabetics, the elderly, and the critically ill and carries a higher mortality rate. Emphysematous cholecystitis is acute cholecystitis with superinfection by gas-forming bacteria and has a more severe course and poorer prognosis. When gallstones become lodged in the common bile duct, the condition is referred to as choledocholithiasis. Choledocholithiasis is associated with ascending cholangitis and pancreatitis.
Gallstones are present in 10–15% of the population in the United States, but only 10–20% of persons with asymptomatic stones will develop complications over a 20-year period, and only 1–3% will develop acute cholecystitis each year. When patients do develop acute cholecystitis, the mortality rate is approximately 4%. The mortality rate for emphysematous cholecystitis is approximately 20%.
Patients with biliary colic present with acute onset of constant crampy pain in the right upper quadrant or epigastrium that may radiate to the back. Pain persisting for more than 6 hours is unusual and should raise concern for early cholecystitis. Nausea and vomiting are present to varying degrees, and fever is usually absent.
Acute cholecystitis presents in much the same way as biliary colic, but symptoms are persistent and localize to the right upper quadrant. The pain may radiate to the right or left shoulder owing to irritation of the diaphragm. Fever may develop but it is often absent, especially in elderly or immunosuppressed patients.