A. 32 Cholelithiasis. Cholecystitis Flashcards
(35 cards)
A. 32 Cholelithiasis. Cholecystitis
define Cholelithiasis.
Cholelithiasis refers to the existence of abnormal gallstones in the gallbladder.
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis.
- Sex Ratio: Female to Male (2-3:1)
- Prevalence: Approximately 10-20% of the adult population in developed countries
- Peak Incidence: Over 40 years of age
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Etiology
Imbalance in Bile Components: Involves bile salts, lecithin (stabilizer), cholesterol, calcium carbonate, and bilirubin.
- Impaired Gallbladder Emptying: This can occur due to factors such as bowel rest or prolonged total parenteral nutrition, and during pregnancy, leading to bile sludge and bile stasis (cholestasis).
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Cholesterol Stones Risk Factors
Cholesterol Stones (Comprising up to 95% of All Stones)
Risk Factors
- Obesity, Insulin Resistance, and Dyslipidemia
- Female Sex:
Notably fertile due to:
- Increased estrogen, which enhances bile rich in cholesterol
- Increased progesterone, leading to smooth muscle relaxation and gallbladder stasis
Multiparity or Multiple Pregnancies
Age:
- Greater than 40 years
- Family History
Malabsorption Conditions:
- Such as Crohn’s disease, ileal resection, or cystic fibrosis
- Rapid Weight Loss
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Cholesterol Stones Pathophys
Abnormal Hepatic Cholesterol Metabolism:
- Increased cholesterol concentration in bile and decreased bile salts and lecithin leads to:
- Hypersaturated bile
- Precipitation of cholesterol and calcium carbonate
- Formation of cholesterol stones or mixed stones
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Black Stone Risk Factors
Black Pigment Stones (< 10% of All Stones)
Risk Factors
- Chronic hemolytic anemias (e.g., sickle cell disease, hereditary spherocytosis)
- Alcoholic cirrhosis
- Crohn’s disease
- Total parenteral nutrition
- Advanced age
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Black Stone Pathophys
- Hemolysis increases circulating unconjugated bilirubin
- This leads to the uptake and conjugation of bilirubin
- Resulting in the precipitation of bilirubin polymers and the formation of stones
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Mixed/Brown Pigment Stones Risk Factors
Mixed/Brown Pigment Stones (< 10% of All Stones)
- Risk Factors:
- Bacterial infections and parasites (e.g., Clonorchis sinensis, Opistorchis species) in the biliary tract
- Sclerosing cholangitis
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Mixed/Brown Pigment Stones Pathophys
- Hemolysis increases circulating unconjugated bilirubin, leading to its uptake and conjugation, which results in the precipitation of bilirubin polymers and stone formation.
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Clinical
Most gallstones are asymptomatic.
- Biliary Colic: Constant, dull RUQ pain lasting less than 6 hours
- Particularly postprandial: Vagal stimulation (e.g., CCK release after a fatty meal) leads to gallbladder contraction, attempting to push the stone into the cystic duct
- Pain may radiate to the epigastric region, right shoulder, and back
- Symptoms include nausea, vomiting, and early satiety.
- Additional symptoms: bloating and dyspepsia.
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis DX
Asymptomatic Cholelithiasis: No diagnostic evaluation is necessary.
- Suspected Symptomatic Cholelithiasis: Imaging is crucial to confirm the clinical diagnosis and exclude concurrent choledocholithiasis.
Laboratory Studies
Usually, results are normal in uncomplicated cholelithiasis, but tests should be conducted to exclude other acute biliary conditions or alternative causes of acute abdominal pain.
- CBC: Typically normal
- LFTs: Generally normal
- Amylase, Lipase: Usually normal
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Imaging
RUQ Ultrasound
Indication: First-line test for suspected symptomatic cholelithiasis.
Characteristic Findings:
- Cholelithiasis
- Highly echogenic foci
- Strong posterior acoustic shadowing
- Biliary Sludge:
- Echogenic material in the dependent part of the gallbladder (GB)
- No posterior acoustic shadowing
- Shadowing may vary with patient posture
MRI Abdomen with IV Contrast and MRCP
Indication: Utilized when initial ultrasound results are inconclusive.
- CT Abdomen with IV Contrast
- Abdominal X-ray
Note: X-rays and CT scans are often not diagnostic for cholelithiasis as only 15-20% of stones are radiopaque. Pure cholesterol stones typically do not appear on these imaging modalities.
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Medical TX
Initial Supportive Therapy for Acute Biliary Disease:
- Bowel Rest: NPO (nil per os)
Analgesics:
- NSAIDs: Preferred options include:
- Ketorolac
- Diclofenac
- Ibuprofen
- Opioids: For severe pain or in patients with contraindications to NSAIDs:
- Morphine
- Buprenorphine
- Meperidine
- Spasmolytics (e.g., dicyclomine): Consider as an adjunct to analgesics in patients with severe pain.
For Patients with Protracted Vomiting, consider the following:
- IV fluid therapy
- Antiemetics
- Nasogastric tube insertion with suction
Important Considerations:
- Advise patients to avoid foods high in fat content.
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Surgical TX
Procedure: Elective Laparoscopic Cholecystectomy
Indications:
- Symptomatic cholelithiasis
- Asymptomatic cholelithiasis with:
- History of gallbladder cancer
- Increased risk of complications
Nonsurgical Alternatives: For patients at high risk for complications due to surgery or anesthesia and those unwilling to undergo surgery:
Expectant Management:
- Lifestyle modifications: Low-fat diet, avoid lithogenic drugs, exercise regularly.
Oral Bile Acid Dissolution Therapy:
- Effective for dissolving pure cholesterol stones ≤ 0.5 cm:
- Ursodeoxycholic Acid
- Treatment duration: 6-24 months
- Extracorporeal Shock Wave Lithotripsy (ESWL)
A. 32 Cholelithiasis. Cholecystitis
Cholelithiasis Complications
General:
- Cholecystitis
- Acute Cholecystitis (most common)
- Chronic Cholecystitis
- Cholelithiasis
- Cholangitis
- Acute Biliary Pancreatitis
- Biliary-Enteric Fistula
Complications Due to Gallstone Impaction:
- Mirizzi Syndrome: External compression of the common bile duct by gallstones lodged in the cystic duct or at the gallbladder infundibulum.
- Gallbladder Mucocele: Distension of the gallbladder (gallbladder hydrops) with thick mucinous content resulting from chronic biliary outflow obstruction.
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis
Epidemiology
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis Etiology
- Sex Distribution: Female > Male
- Prevalence: Most common complication of cholelithiasis
- Peak Incidence: Occurs primarily in individuals over 50 years old
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis Clinical Features
- Acute Calculous Cholecystitis: Most common form, accounting for 90%
- Cause: Obstructing cholelithiasis
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis- Pathophysiology
- Gallstones pass into the cystic duct, leading to obstruction, cystic duct blockage, and inflammation of the gallbladder.
- Secondary bacterial infections (e.g., E. coli, Klebsiella, Enterobacter, Enterococcus spp.) may also occur, although they are not required for the development of cholecystitis.
- Acalculous Cholecystitis: Accounts for 5–10% of acute cholecystitis cases.
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis Clinical
Clinical Features
- RUQ Pain:
- Generally more severe and longer-lasting (> 6 hours) than biliary colic.
- Often occurs after meals (postprandial).
- May radiate to the right scapula.
Positive Murphy Sign - The act of the patient suddenly pausing during inspiration upon deep palpation of the right upper quadrant due to pain. A strong indicator of cholecystitis.
- Can be falsely negative in patients over 60 years.
Additional Symptoms:
- Guarding
- Fever, malaise, and anorexia
- Nausea and vomiting
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis DX
The diagnosis of acute cholecystitis relies on distinct clinical features, systemic signs of inflammation (such as leukocytosis and elevated CRP), and evidence of gallbladder inflammation on imaging.
Clinical Features:
- Blood cultures: Should be obtained, especially in patients with acute cholecystitis.
- Blood Cultures: Recommended for patients undergoing laparoscopic cholecystectomy or gallbladder drainage.
Tests to Assess Severity of Disease:
- Blood Gas Analysis: PaO2/FiO2 ratio < 300 in severe acute cholecystitis.
- BMP: Monitor for acute kidney injury, which can be more prevalent in patients with severe disease.
Tests to Rule Out Related Comorbidities:
- Testing should be performed in patients suspected of having cholecystitis.
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis Labs
Liver Function Tests (LFTs)
- Liver Enzymes:
- Mild increases in AST and ALT may occur in acute cholecystitis.
- Elevated bilirubin, ALP, and GGT are rare in cholecystitis; if these are present, consider possible biliary obstruction.
Lipase and Amylase:
- Mild elevation of amylase can be observed in cases of acute cholecystitis.
- Significant elevation of lipase or amylase (≥ 3 times normal) indicates acute biliary pancreatitis.
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis Imaging
RUQ Ultrasound (Preferred Initial Modality in Suspected Acute Cholecystitis)
Characteristic Findings:
- Gallbladder wall thickening (3–5 mm).
- Gallbladder distension (≥ 10 x 4 cm).
- Gallbladder wall edema (double-wall sign): Appears as a hypoechoic layer between the innermost and outermost layers, indicating edema.
Positive Murphy sign on examination.
- Possible presence of gallstones or biliary sludge.
- Important Consideration: Assess the common bile duct (CBD) for choledocholithiasis.
Hepatobiliary Iminodiacetic Acid (HIDA) Scan
- Indications: Recommended if initial ultrasound is inconclusive for suspected uncomplicated acute cholecystitis.
- MRI Abdomen with IV Contrast (if further evaluation is needed).
A. 32 Cholelithiasis. Cholecystitis
Acute Cholecystitis TX
Treatment
Empiric antibiotic therapy and cholecystectomy are the primary treatments for acute cholecystitis following initial supportive care. Laparoscopic cholecystectomy should be conducted as soon as possible unless the risks of surgery and anesthesia outweigh the benefits of urgent intervention.
- In cases of grade II-III acute cholecystitis or in patients with a high risk of surgical complications, a temporary gallbladder drainage may be performed. This allows for elective interval cholecystectomy to be scheduled when the risks associated with surgery and anesthesia are minimized.
