Makindo Medical Notes

Related Subjects:Acute Cholecystitis |Acute Appendicitis |Chronic Peritonitis |Abdominal Aortic Aneurysm |Ectopic Pregnancy |Acute Cholangitis |Acute Abdominal Pain/Peritonitis |Assessing Abdominal Pain |Penetrating Abdominal Trauma |Acute Pancreatitis |Acute Diverticulitis

Mortality from acute cholecystitis is estimated to be less than 10% with prompt treatment. However, acute acalculous cholecystitis is a life-threatening condition with a mortality rate of up to 50% and requires urgent attention. This form is more common in critically ill patients and is associated with a high risk of complications.

About

• Prevalence: Gallstones are found in about 10% of the population, with the majority being asymptomatic. Only 10-20% develop symptoms requiring treatment.
• Pathophysiology: Acute cholecystitis occurs when a gallstone obstructs the cystic duct, leading to increased pressure, bile stasis, and inflammation of the gallbladder wall.
• Demographics: More common in women, with incidence increasing with age. Affects about 15% of males and 24% of females by age 70.
• Treatment: Symptomatic patients often require cholecystectomy, usually performed laparoscopically, after confirming the absence of stones in the common bile duct (CBD).

Aetiology

• Lithogenic Bile: Excess insoluble cholesterol and insufficient bile acids promote gallstone formation, leading to ductal obstruction.
• Cystic Duct Obstruction: Most cases are due to obstruction of the gallbladder neck or cystic duct by a gallstone, leading to inflammation.
• Chemical vs. Infectious Inflammation: Initial inflammation is often chemical due to bile stasis, but secondary bacterial infection can occur, with common pathogens like E. coli and Klebsiella.
• Empyema: In severe cases, the gallbladder can fill with pus, leading to an empyema that requires surgical drainage.

Risk Factors for Gallstones

• Age > 50, Female, Caucasians, Diabetes
• Obesity, Rapid weight loss
• Terminal ileal disease (e.g., Crohn's disease), Cholestyramine usage
• Pregnancy, Cystic fibrosis, Metabolic syndrome

Types of Gallstones

Clinical Features

• Typical Presentation: Sudden-onset, constant, severe right upper quadrant (RUQ) pain lasting several hours, often radiating to the right shoulder or scapula.
• Associated Symptoms: Anorexia, nausea, vomiting, and fever are common. The patient may appear systemically unwell.
• Murphy's Sign: Pain on deep inspiration when pressure is applied to the RUQ; highly suggestive of cholecystitis.
• Jaundice: May indicate common bile duct obstruction by a gallstone or secondary cholangitis.

Investigations

• Blood Tests: FBC may show leukocytosis, elevated CRP, and mild liver enzyme elevations (ALT, AST, GGT, ALP). Elevated bilirubin may indicate CBD stones.
• Ultrasound: First-line imaging for gallstones and gallbladder wall thickening. Sonographic Murphy's sign and pericholecystic fluid may be present.
• CT Scan: Useful for evaluating complications such as gallbladder perforation or abscess when ultrasound results are inconclusive.
• MRCP: Used to visualize stones within the common bile duct (CBD) if suspected.
• ERCP: Both diagnostic and therapeutic for removing stones in the CBD. Should be followed by elective cholecystectomy.

Calot's Triangle: The Cystohepatic triangle, bounded by the cystic duct, common hepatic duct, and cystic artery, must be identified during laparoscopic cholecystectomy to avoid injury.

Complications

Differential Diagnosis

• Peptic ulcer disease, liver abscess, and hepatic pathologies.
• Acute pancreatitis, myocardial infarction, or pneumonia presenting with referred pain.

Management

• Pain Management: Provide adequate analgesia (e.g., IV morphine) and keep the patient NBM (nil by mouth) to prevent further stimulation of the gallbladder.
• Antibiotics: Start IV broad-spectrum antibiotics such as Cefuroxime and Metronidazole.
• Surgical Intervention: Laparoscopic cholecystectomy is the treatment of choice for acute calculous cholecystitis and should ideally be performed within 5 days of symptom onset.
• Delayed Cholecystectomy: Consider in high-risk patients; usually performed 6 weeks post-recovery.
• ERCP: Necessary for CBD stone removal before surgery if biliary obstruction is present.

References

• NICE Guidelines: Acute Cholecystitis
• Acute Cholecystitis: Diagnosis and Management