GI Flashcards
(225 cards)
What is the pathophysiology of cholelithiasis?
Excess hepatic cholesterol secretion relative to bile salts and lecithin (solubilizing agents) = supersaturated cholesterol which precipitates gallstone formation
Risk factors for cholesterol stones
“5F’s”:
- Female
- Fair
- Forty
- Fat
- Fertile
What demographic also has a high incidence of cholelithiasis?
Pima Indians population
Risk factors for pigment stones
- Cirrhosis
- Chronic hemolysis
- Biliary stasis
Protective factors for cholelithiasis
- Statin
- Coffee
- Vitamin C
- Exercise
Symptoms of cholelithiasis
- Asymptomatic in 80%
2. Biliary colic (10-25%)
Treatment for cholelithiasis
Most don’t require treatment.
Consider cholecystectomy if risk of malignancy.
What conditions increase the risk of gallbladder malignancy/require cholecystectomy?
- Cholechondral cysts
- Caroli’s disease
- Porcelain gallbladder
- Sickle cell disease
- Pediatric patient
- Bariatric surgery
- Immunsuppression
Investigations for cholelithiasis
- Normal bloodwork (FBC, LFTs, bilirubin, lipase, amylase)
- USS diagnostic procedure of choice
- HIDA scan (cholescintigraphy) - rarely used
What is the radioisotope used in HIDA scan?
IV technetium-99 radioisotope
What causes biliary colic?
Gallstone transiently impacting cystic duct, no infection
Features of biliary colic
- steady, dull RUQ/epigastric pain lasting minutes to hours (<6h)
- crescendo-decrescendo pattern
- Worse after fatty meal + at night, not after fasting
- N/V
- R shoulder tip pain, chest pain, scapular pain
- No peritoneal/systemic signs
Investigations for biliary colic
- Normal bloodwork (FBC, U&Es, LFTs, bilirubin, amylase)
2. USS shows cholelithiasis, may show stone in cystic duct
Treatment for biliary colic
- Analgesia (paracetamol + NSAIDs for mild-moderate pain; IM diclofenac/opioid for severe pain)
- Rehydration during colic episode
- Elective laparoscopic cholecystectomy (95% success)
What are complications of elective laparoscopic cholecystectomy?
- CBD injury
- Hollow viscus injury
- Bile peritonitis
- Vessel injury leading to liver damage
Cause of acute cholecystitis
- Inflammation of gallbladder resulting from sustained gallstone impaction in cystic duct or Hartmann’s pouch (postern-medial wall of gallbladder neck; normal variation)
- No cholelithiasis in 5-10%
- History of biliary colic
Features of acute cholecystitis
- Severe constant (>6h) epigastric/RUQ pain
- Anorexia
- N/V
- Low grade fever (>38.5)
- Focal peritoneal signs (Murphy’s sign, palpable/tender gallbladder; Boas’ sign - R sub-scapular pain)
Investigations for acute cholecystitis
- Bloods show high WBC + left shift, mildly elevated bilirubin (either stones or Mirizzi syndrome)
- USS (consider HIDA if USS negative)
What are the signs of acute cholecystitis on USS?
- Gallbladder wall thickening > 4mm
- Oedema (double-wall sign)
- Gallbladder sludge
- Cholelithiasis
- Pericholecystic fluid
- Sonographic Murphy’s sign
Complications of acute cholecystitis
- Gangrenous gallbladder (20%)
- Perforation (10% - abscess formation or local peritonitis)
- Mirizzi syndrome (extra-luminal compression of CBD/CHD due to large stone in cystic duct - associated with gallbladder cancer)
- Empyema of gallbladder (suppurative cholecystitis + sick pt)
- Emphysematous cholecystitis (bacterial gas present in gallbladder lumen, wall or pericholecystic space - risk in diabetic patient)
- Cholecystoenteric fistula (from repeated attacks of cholecystitis) –> gallstone illeus
What organisms are involved in emphysematous cholecystitis?
- C welchii
- E coli
- Klebsiella
- Anaerobic streptococci
- Enterococcus
Treatment for acute cholecystitis
- Admit, hydrate, NBM, NG tube, analgesia
- Antibiotics (cefazolin if uncomplicated cholecystitis)
- ERCP prior to surgery if CBD stones are present on USS (MRCP ± ERCP if CBD markedly dilated or CBD stones suspected)
- Cholecystectomy (within 72h preferred)
- Percutanoues cholecystostomy tube: critically ill or if general anaesthetic contraindicated
- Percutaneous stone extraction
What is acalculous cholecystitis?
Acute or chronic cholecystitis in the absence of stones
Causes of acalculous cholecystitis
- Gallbladder ischemia
2. Gallbladder stasis