Gastrointestinal Flashcards
Describe the differences between ulcerative colitis and Crohn’s disease.
Ulcerative colitis is diffuse inflammation while Crohn’s disease is patchy inflammation.
UC is superficial (mucosal); CD is transmural
UC affects rectum and extends proximally; CD may affect any part of the GIT
What are some histological features of ulcerative colitis?
- mucosal/submucosal inflammation
- lymphocytic infiltrate
- NO granulomas
- goblet cell depletion
- crypt distortion
- cryptitis
- crypt abscesses
What are some histological features of Crohn’s disease?
- transmural inflammation
- lymphocyte + macrophage infiltrate
- granulomas in 50% cases *** if you see granulomas, then CD, not UC
What is the possible aetiology of IBD?
- Abnormal immune response
- inappropriate activation of the immune system
- failure to downregulate immune system - Environmental triggers
- diet, medications, psychological stress
- smoking protects against UC
- appendicetomy protects against UC - Genetics
- possible susceptibility genes (NOD2/CARD15 for Crohn’s)
How may IBD present in patient?
Note: clinical presentation depends on location, extent and severity. GI symptoms: - abdominal cramps - diarrhoea - rectal bleeding - urgency - tenesmus Systemic symptoms: - weight loss - malaise - anorexia - fever - arthralgia Perianal involvement (20-25%) - abscesses - fistulae - fissures Extraintestinal manifestations
What are the extraintestinal manifestations of IBD?
Associated with active GI disease: - oral ulcers - erythema nodosum - large joint arthritis - episcleritis Independent of GI disease: - Primary Sclerosing Cholangitis (PSC) - ankylosing spondylitis - uveitis - pyoderma gangrenosum - kidney stones - gallstones
How do you differentiate IBD from IBS?
History: - systemic symptoms, e.g. weight loss - nocturnal symptoms - continuous (rather than intermittent) symptoms - extraintestinal manifestations - FHx of IBD Examination: - PR bleeding - extraintestinal manifestations - perianal involvement Investigations: - anaemia - iron or other nutrient deficiencies - raised inflammatory markers (CRP, ESR) - elevated faecal calprotectin
How do we diagnose IBD?
Colonoscopy confirms diagnosis
- it also determines the extent and severity of the disease
- can also provide therapeutic dilatation of strictures
- also surveillance for CRC
What are the distinguishing features of Crohn’s disease?
- Granulomas
- Asymmetrical involvement
- Focal lesions
- Strictures
- Skip lesions
- Fistulisation
- Small bowel involvement
- Rectal sparing
What are the goals of management for IBD?
Short term goal = induce remission - relieve symptoms and improve QOL Long term goal = maintain remission - control inflammation (w/o steroids) - prevent flares - prevent complications - reduce need for hospitalisation or surgery
What are the complications of ulcerative colitis?
Haemorrage Growth retardation Osteoporosis Thromboembolism Colorectal cancer *Toxic megacolon (*unique to UC)
What are the complications of Crohn’s disease?
Haemorrage Growth retardation Osteoporosis Thromboembolism Colorectal cancer *Strictures *Fistulae *Perforation *Abscess
What are the key functions of the liver?
- Synthesis of clotting factors
- Glucose homeostasis
- Albumin synthesis
- Conjugation and clearance of bilirubin
- NH3 metabolism
- Drug metabolism
- Immune
What is the definition of acute liver failure?
Rapid deterioration of liver function (within 30 days), specifically characterised by encephalopathy due to excess ammonia.
What are the causes of chronic liver disease?
The Big 3:
- HBV
- HCV
- Alcohol
Autoimmune 3
- Autoimmune hepatitis (AIH)
- Primary biliary cirrhosis (PBC)
- Primary slcerosing cholangitis (PSC)
Metabolic 3:
- Haemachromatosis
- Wilson’s disease
- Fatty liver disease (NASH)
Other 3:
- Budd-Chiari (hepatic vein thrombosis)
- Chronic biliary obstruction
- alpha 1-antitrypsin deficiency
What is hepatitis and what are its causes?
Hepatitis is inflammation of the liver. Causes include: - viruses - alcohol - drug-induced - idiopathic
How may someone with chronic liver disease present?
- Ascites, oedema (due to hypoalbuminaemia)
- Bleeding, bruising (due to reduced clotting factors)
- Jaundice (due to hyperbilirubinaemia)
- Encephalopathy (due to ammonia)
- Varcies +/- bleeding, ascites (due to portal HTN)
What are some of the risk factors for chronic liver disease?
These are risk factors for the possible causes of CLD: Alcoholism (EtOH) IVDU (Hep B or C) Ethnic background (Hep B) Obesity or T2DM (NASH) Middle-aged women (autoimmune causes) Ulcerative colitis (PSC)
What are the three main things we are looking for on examination of a patient with chronic liver disease?
- Stigmata of chronic liver disease
- Signs of an underlying pathology
- Signs of decompensation
What are some signs you may find on examination of a patient with chronic liver disease?
Hands/arms - clubbing (arterial hypoxaemia) - leuconychia (hypoalbuminaemia) - palmar erythema (oestrogen) - Duputren's contracture (alcoholism) - metabolic flap (ammonia) - bruising Face - jaundice - parotidomegaly (alcoholism) Chest - spider naevi (oestrogen, pathognomonic of cirrhosis) - gynaecomastia (oestrogen) - jaundice Abdomen - ascites
What are the signs of decompensation in chronic liver disease?
These are signs that the liver is no longer able to perform its key functions:
- ascites
- hepatic encephalopathy
- variceal bleeding
- hepatorenal syndrome
- bacterial peritonitis
What investigations should you order for chronic liver disease?
Remember BRO
Bloods:
- FBE looking for thrombocytopaenia, neutrophilia
- UEC looking for indication of hepatorenal syndrome
- LFT looking for hypoalbuminaemia, hyperbilirubinaemia
- INR looking for elevation due to decreased clotting factors
- CRP, ESR looking for inflammation
Other blood tests for underlying cause:
- ETOH
- HBV, HCV serology
- ANA/AMA, ANCA for autoimmune causes
- iron studies, copper caeruloplasmin for metabolic causes
Radiology:
- abdominal ultrasound looking for cirrhosis (small liver, coarsened, nodules), portal HTN (enlarged spleen, ascites), HCC (mass in liver)
- AXR
Other:
- liver biopsy to grade and stage cirrhosis
- FibroScan
- gastroscopy for complications e.g. varices
What is the management of chronic liver disease?
- Treat the cause
- alcohol, viral, metabolic, autoimmune, etc. - Manage and prevent complications
- Consider liver transplant
What are the complications of chronic liver disease?
Hepatorenal syndrome: renal failure due to CLD Hepatocellular carcinoma (HCC) Metabolic failure Osteoporosis Malnutrition
