Liver and GI Flashcards
What causes death when the liver fails?
Hypoglycaemia due to failed glucogenesis and glycogenolysis
What are the functions of the liver?
- Protein synthesis (albumin, clotting factors)
- Glucose and fat metabolism
- Defence against infection
- Detoxification and excretion (e.g. ammonia, drugs, hormones)
Where does the liver get its blood supply?
Dual supply from portal vein from the gut and hepatic artery
Which vessel carries blood away from the liver?
Hepatic vein
Which part of the liver lobule is most likely to be affected by toxins?
Zone 3 (i.e. the hepatocytes around the hepatic vein as these have the least access to oxygen and nutrients)
What does acute liver injury lead to?
Either liver failure or recovery
What does chronic liver injury lead to?
Either recovery or cirrhosis (which can lead on to acute on chronic liver failure, varices and hepatoma)
What is seen on histology in acute liver injury?
- Apoptosis (seen as eosinophilic areas)
- Fibrosis
- Macrophages
- Ballooned hepatocytes
How does acute liver injury present?
Malaise, nausea, anorexia, jaundice (rarely - confusion and liver pain)
How does chronic liver injury present?
Ascites, oedema, haematemesis, malaise, anorexia, wasting, easy bruising, itching, hepatomegaly, abnormal LFTs
(rarely - jaundice, confusion)
Which blood tests give some index of liver function?
Serum bilirubin, albumin and prothrombin time
Which blood ‘liver function tests’ actually give no index of liver function?
Serum liver enzymes, alkaline phosphatase, gamma-GT, transaminases (AST, ALT)
What is jaundice?
Yellow appearance of the skin caused by raised serum bilirubin
What is pre-hepatic jaundice and what causes it?
Pre-hepatic jaundice is caused by raised unconjugated serum bilirubin and is caused by Gilbert’s syndrome and haemolysis
Raised conjugated bilirubin is found in which types of jaundice?
Hepatic (liver disease), post-hepatic (due to bile duct obstruction)
What is Gilbert’s syndrome?
An inherited liver disorder that affects the body’s ability to process bilirubin - don’t produce enough liver enzymes to keep bilirubin at a normal level
What are the possible causes of hepatic jaundice?
Hepatitis (caused by drugs/autoimmune/alcohol), ischaemia, neoplasm and congestion
What are the possible causes of post-hepatic jaundice?
Gallstones, malignancy, ischaemia, inflammation
How can we differentiate between pre-hepatic and hepatic/post-hepatic jaundice?
Pre-hepatic: normal urine, normal stools, no itching, normal liver tests
Hepatic/post-hepatic: Dark urine, potentially pale stools, possible itching, abnormal liver tests
What does very high AST/ALT suggest?
Liver disease (although some exceptions), jaundice with high AST/ALT enzymes more likely to have hepatic cause.
Besides blood tests, what other investigations can be useful in assessing jaundice?
CT
MRCP (magnetic resonance cholangiogram)
ERCP (endoscopic retrograde cholangiogram)
What are gallstones made of?
Cholesterol, bile duct pigment +/- calcium
What are the three classifications of gallstones?
- Intrahepatic bile duct stones (hepatolithiasis)
- Extrahepatic bile duct stones (choledocholithiasis) in the common bile duct
- Gallbladder stones (cholecystolithiasis)
How do gallbladder stones (cholecystolithiasis) normally present?
Right upper quadrant pain, cholecystitis, possible obstructive jaundice, no evidence of cholangitis or pancreatitis
How do bile duct stones (choledocholithiasis) normally present?
No cholecystitis or ‘biliary’ pain. Obstructive jaundice, cholangitis and pancreatitis present.
How are gallbladder stones normally managed?
Via laparoscopic cholecystectomy (if symptomatic)
Can offer bile acid dissolution therapy instead if patient is not fit for surgery
How are bile duct stones usually managed?
ERCP with sphincterotomy with removal (via basket or balloon), crushing (mechanical/laser) and possible stent placement.
Large stones may need to be removed surgically.
Acute stone obstruction will normally show what on liver enzyme tests?
Alkaline phosphatase usually normal
Initial ALT often high >1000
Which antibiotic used to treat and prevent TB can be associated with elevated transaminases?
Isoniazid
Which drugs are most likely to cause liver injury?
Antibiotics, CNS drugs (e.g. valproate, carbamazepine), immunosuppressants (e.g. azathioprine), analgesics (e.g. diclofenac), GI drugs (e.g. PPIs), dietary supplements.
What drugs apparently don’t cause liver injury?
Low dose aspirin NSAIDs (except diclofenac) Beta blockers HRT ACE inhibitors Thiazides Calcium channel blockers
What drug is given to treat paracetamol overdose?
N acetylcysteine (NAC)
When might a paracetamol overdose require an emergency liver transplant?
- Late presentation (NAC less effective >24h)
- Acidosis
- Prothrombin time >70s
- Serum creatinine >300umol/l
Why is ascites associated with chronic liver disease?
CLD causes systemic dilatation, which leads to the secretion of renin, noradrenaline and vasopressin, which causes fluid retention.
Low albumin also leads to ascites.
What are the management options for ascites?
Fluid and salt restriction, high caloric intake
Diuretics: spironolactone +/- furosemide
To drain fluid:
Large-volume paracentesis
Trans-jugular intrahepatic portosystemic shunt (TIPS)
What is normally seen in the early stages of alcoholic liver disease?
Fatty liver
What is cirrhosis of the liver?
Irreversible architectural change to the liver due to fibrosis
What is the main cause of liver death in the UK?
Alcoholic liver disease
Why might a patient with liver disease present with haematemesis?
Due to bleeding varices in the oesophagus
What drug can be used to treat alcoholic liver disease, although the response is variable?
Prednisolone
What are the main reversible causes of encephalopathy in liver disease patients?
- Constipation
- Drugs
- GI bleed
- Infection
- Hypo- (natraemia, kalaemia, glycaemia..)
What infections are liver patients vulnerable to?
Spontaneous bacterial peritonitis, septicaemia, pneumonia, skin infections, UTIs
What is the most common serious infection seen in liver cirrhosis patients?
Spontaneous bacterial peritonitis
What might cause renal failure in liver disease patients?
Drugs (esp. diuretics, NSAIDs, ACE inhibitors)
Infection, GI bleeding, myoglobinuria, renal tract obstruction
What drugs must be avoided completely in patients with liver disease?
NSAIDs (due to renal failure)
ACE inhibitors (although these patients don’t tend to have high BP anyway)
Aminoglycosides (e.g. gentamicin)
What are the possible causes of chronic liver disease?
- Alcohol
- NASH (Non-alcoholic steatohepatitis)
- Viral hepatitis
- Immune disease (e.g. autoimmune hepatitis, primary biliary cholangitis, sclerosing cholangitis)
- Metabolic disease: haemochromatosis, Wilson’s disease, alpha-1 antitrypsin deficiency
- Vascular disease: Budd-Chiari
Which immunoglobulin is raised in autoimmune hepatitis?
IgG
Which immunoglobulin is raised in primary biliary cholangitis?
IgM
What are the three main autoimmune liver diseases?
Autoimmune hepatitis
Primary biliary cholangitis
Primary sclerosing cholangitis
Which autoimmune liver disease responds well to steroid treatment with prednisolone +/- azathioprine?
Autoimmune hepatitis
How can primary biliary cirrhosis/cholangitis present?
Asymptomatic abnormal LFTs (bilirubin, thrombin time, albumin), itching, fatigue, dry eyes, joint pain, variceal bleeding, liver failure.
What can be used to treat cholestatic itch?
- Antihistamines don’t help much
- Cholestyramine helps in 50% of cases
- Opiate antagonists (e.g. naloxone)
- UV light
- Plasmapheresis
What can be used to treat fatigue in primary biliary cholangitis?
Modafinil
What abnormalities would show up on blood tests for primary sclerosing cholangitis?
Raised alkaline phosphatase and GGT
How does primary sclerosing cholangitis often present?
Itching, pain +/- rigors, jaundice
What are the clinical features of haemochromatosis?
- Hepatomegaly
- Cirrhosis
- Hepatocellular carcinoma
- Flat, white nails
- Koilonychia (spoon nails)
- Joint pain and osteoporosis
- Chronic fatigue
- Diabetes mellitus
- Melanoderma, skin dryness
What would a liver biopsy of a patient with hepatocellular carcinoma show?
Hepatocytes growing in large clumps with large nuclei
What do 50% of hepatocellular carcinoma patients produce?
Alpha fetoprotein
What drug has recently been shown to extend the lives of patients with hepatocellular carcinoma?
Sorafenib
How might hepatic vein occlusion present?
Abnormal liver tests
Ascites
Acute liver failure
What are the treatment options for hepatic vein occlusion?
Anticoagulation
Transjugular intrahepatic portosystemic shunt
Liver transplantation
What is the definition of diarrhoea?
The passage of increased loose/watery stools, at least 3 times in 24 hours
How are acute, persistent and chronic diarrhoea defined?
Acute - 14 days or fewer
Persistent - 14-30 days
Chronic - >30 days
What is dysentery?
An infection of the GIT that leads to diarrhoea containing blood or mucus
What are the potential non-infective causes of diarrhoea?
Cancer and related treatments, chemical diarrhoea (poisoning, medication, sweeteners), IBD (Crohn’s, UC), IBS, malabsorption, endocrine causes (e.g. thyrotoxicosis)
Which common viruses cause watery diarrhoea?
Rotavirus, norovirus
Which parasites cause watery diarrhoea?
Giardia and cryptosporidium
What are the 6 pathogenic serotypes of E coli?
- ETEC (enterotoxigenic)
- EHEC (enterohaemorrhagic
- EIEC (enteroinvasive)
- EPEC (enteropathogenic)
- EAEC (enteroaggregative)
- DAEC (diffusely adherent)
What is the most common cause of traveller’s diarrhoea?
Enterotoxigenic E coli (ETEC)
What pathogen associated with canned meat can cause severe diarrhoea and vomiting?
Clostridium perfringens
What bacterium can cause a type of quick-onset self-limiting food poisoning as a result of food not being refrigerated?
Staph aureus
Persistent infective diarrhoea is more likely to be caused by which pathogens?
Parasites - Giardia, Cryptosporidium
Which invasive bacteria cause diarrhoea?
CESSY Campylobacter E Coli (EIEC, STEC) Salmonella enteritidis Shigella dysenteriae Yersinia (rare)
Which antibiotics have the biggest association with diarrhoea?
Cephalosporins (Cefuroxime, Cefalexin, Ceftriaxone)
Clindamycin
Co-amoxiclav
Ciprofloxacin
What pathogen causes significant diarrhoea in healthcare settings as a result of antibiotics killing off the natural protective bacteria in the gut?
Clostridioides (previously known as C diff)
What drug is used to treat clostridioides?
Vancomycin
What stool tests should be requested when investigating diarrhoea?
Microscopy Culture Multi-pathogen molecular panels Ova, cysts and parasites Toxin detection
What blood tests should be requested when investigating diarrhoea?
Blood cultures
Inflammatory markers
Electrolytes and creatinine
What are the ‘red flags’ for diarrhoea patients?
- Dehydration
- Electrolyte imbalance
- Renal failure
- Immunocompromise
- Severe abdominal pain
- Cancer risk factors (over 50, chronic diarrhoea, weight loss, blood in stool, FH of cancer)
What are the two types of liver abscesses?
- Pyogenic (pus forming - bacterial)
2. Amoebic
How do liver abscesses present?
Fever, RUQ pain, nausea, vomiting, anorexia, weight loss, malaise
How are liver abscesses diagnosed?
Imaging - abdo CT/USS
Blood cultures
Aspirate and culture of abscess material
How are liver abscesses treated?
Drainage and antibiotics
Which pathogen increases the risk of gastritis and peptic ulcers?
Helicobacter pylori
What is the treatment for H pylori?
Omeprazole (or other PPI), clarithromycin and amoxicillin
How is H pylori diagnosed?
Stool antigen test
Breath test
Blood test for antibodies
Endoscopy for biopsy (biopsy urease test, histology)
Which pathogens cause enteric fever?
Salmonella typhi (typhoid) Salmonella paratyphi (paratyphoid)
How does enteric fever present?
Generalised abdominal pain, fever and chills Headache and myalgia Relative bradycardia Rose spots (rare) Constipation/green diarrhoea
How is enteric fever diagnosed?
Blood/bone marrow cultures
What are the potential complications of enteric fever?
GI bleed, perforation/peritonitis, myocarditis, abscesses
What antibiotics can be used to treat enteric fever?
Azithromycin, ciprofloxacin, cephalosporins
Meropenem only as a last resort
What are the three types of GI obstruction?
- Intraluminal obstruction
- Intramural obstruction
- Extramural obstruction
Name three possible causes of intraluminal obstruction in the gut.
- Tumours - more common in the large bowel
- Diaphragm disease - a fibrous diaphragm forms in the gut lumen, leaving only a tiny hole for contents to move through
- Gallstone ileus - caused by massive gallstone forming a fistula so the gallstone ends up in the bowel (rare)
Name four possible causes of intramural obstruction in the gut.
- Crohn’s disease
- Diverticulitis
- Intramural tumours
- Hirschsprung’s disease
What is diverticulitis?
Outpouchings of the bowel (diverticula) form - possibly due to pressure with low fibre diet pushing the mucosa through the holes in the muscle layers where the blood vessels are.
What is a major possible complication of diverticulitis?
Rupture of diverticuli, which can result in faecal contents leaking into the peritoneal cavity, which leads to peritonitis.
What is Hirschsprung’s disease?
A lack of ganglia in the wall of the bowel, leading to a lack of innervation, hence gut is unable to contract and the gut becomes dilated and distended.
Name three possible causes of extramural obstruction in the gut
- Adhesions
- Volvulus
- Peritoneal deposits from tumours
What causes adhesions in the gut?
Fibrous bands of tissue in the peritoneal cavity that draw loops of bowel together and cause obstruction. Often caused by abdominal surgery (inflammation).
How are gut adhesions treated?
Adhesiolysis
Why does volvulus only occur in the sigmoid colon?
Because it’s not fixed to the peritoneum by mesentery like the rest of the colon is
What type of cancer can easily spread through the peritoneal cavity and why?
Ovarian carcinoma - the peritoneal cavity is a smooth, moist membrane with a blood supply, making a favourable environment for secondary cancers to grow.
What condition that happens in the elderly and children results in ‘telescoping’ of a section of gut into another section of gut?
Intussusception
Name four possible aetiologies of non-mechanical small bowel obstruction
- Paralytic ileus after abdominal surgery
- Localised intrabdominal abscess and generalised peritonitis
- Mesenteric thromboembolism
- Intestinal pseudo-obstruction
Name two possible aetiologies of non-mechanical large bowel obstruction
- Retroperitoneal haematoma leading to chronic dilatation of the large bowel (Ogilvie’s syndrome)
- Idiopathic slow gut motility
How can intestinal obstruction cause death?
Dilation caused by increased intraluminal pressure results in compression of blood vessels with oedema of the bowel wall, leading to bacterial colonisation, necrosis, perforation, peritonitis and haemodynamic compromise, resulting in death.
What are the main features of bowel obstruction?
Abdominal pain
Nausea and vomiting
Constipation
Distension
How does small bowel obstruction present?
Severe sudden onset with central, colicky pain, distension, constipation and vomiting straight away, which may contain bile.
How does large bowel obstruction present?
Chronic lower abdominal colicky pain, vaguely localised. Possible delayed vomiting, absolute constipation (no gas or stool) followed by peripheral distension.
What might you see on visual inspection of a patient with bowel obstruction?
Surgical scar
Distension (centrally in SBO, peripherally in LBO)
Visible peristalsis
What might you feel on palpation of a patient with bowel obstruction?
An abdominal mass in the case of a tumour or strangulated bowel
Rigidity and rebound tenderness indicative of ischaemia and peritoneal irritation
What might you notice on percussion of a patient with bowel obstruction?
Resonance
Tenderness on percussion indicative of peritonitis
What might you notice on auscultation of a patient with bowel obstruction?
Metallic sounding clicks
Silence if the bowel is completely worn out
Borborygmi (very loud bowel sounds that don’t require a stethoscope)
When performing a rectal examination, what might you notice in a patient with bowel obstruction?
Impacted faeces, rectal cancer, blood
What might blood on rectal examination indicate in a patient with symptoms of bowel obstruction?
Mesenteric artery occlusion intussusception, volvulus
What blood tests should be carried out on a patient admitted with bowel obstruction?
- FBC
- Serum electrolytes + U&Es
- Arterial blood gas analysis
- G&S in case patient needs to go to theatre
What radiological examinations can be performed to help diagnose bowel obstruction?
CT scan (preferred) Abdominal x-ray
What non-operative treatments can be given to manage dynamic bowel obstruction in stable patients with a partial obstruction only?
- GI decompression, NG tube insertion and aspiration
- IV fluids
- Antibiotics
- Gastrografin follow-through
What types of invasive management can be used to treat bowel obstruction?
- Endoscopic decompression for volvulus
2. Surgery to treat the cause of bowel obstruction e.g. bowel resection/anastomosis/stoma formation
How can paralytic ileus be managed?
IV fluids, NG decompression, electrolyte correction, endoscopic decompression, insertion of flatus tube, IV neostigmine, segmental resection and anastomosis/stoma, caecostomy/ileostomy
What is Barrett’s oesophagus?
Metaplasia in the oesophagus causes some of the squamous epithelium to become glandular mucosa instead. Precursor to oesophageal cancer.
Why would squamous epithelium in the oesophagus become glandular mucosa?
Acid reflux damages the squamous epithelium and it grows back as glandular epithelium with a mucin layer to protect the oesophagus from acid.
What type of cancer can form in the oesophagus due to Barrett’s oesophagus?
Adenocarcinoma (carcinoma formed from glandular tissue)
What is a late symptom of oesophageal cancer?
Dysphagia (caused by obstruction)
What foods are potentially linked to gastric cancer?
Smoked foods and pickles
What pathogen increases the risk of gastric cancer slightly?
Helicobacter pylori
What is the natural history of gastric cancer?
Normal gastric mucosa undergoes intestinal metaplasia, then becomes dysplastic and can form an intramucosal carcinoma, which can then become invasive, particularly if growing out of the stomach.
What are the greatest risk factors for colorectal cancer?
- Adenomas
- Age (1/3 of people over 60 have colorectal adenomas)
- Hereditary conditions e.g. familial adenomatous polyposis (almost always causes colon cancer)
What staging system is used for bowel cancer?
Duke’s staging - A/B/C/D - depending on invasion of bowel wall
Why might aspirin help prevent colorectal cancer?
Because NSAIDs appear to reduce the frequency of adenomas
Why does colorectal cancer have a higher survival rate than oesophageal and gastric cancer?
Detected earlier because:
- Symptoms of constipation, diarrhoea, rectal bleeding more likely to be reported and investigated than e.g. indigestion and heartburn
- Colorectal cancer screening for over 60s leads to more early cancers being detected.
What is diarrhoea?
A change in frequency and consistency of stools
Give 6 non-infective causes of diarrhoea
- Neoplasm
- Inflammatory
- Irritable bowel
- Hormonal
- Anatomical (e.g. abnormality that prevents bowel from being cleared properly)
- Chemical (e.g. toxins)
What is a marker for inflammation of the bowel?
Faecal calprotectin
Which organisms cause bloody diarrhoea?
Campylobacter Some strains of E coli Shigella Salmonella Yersinia
Which organisms cause non-bloody diarrhoea?
Clostridium, viruses (e.g. rotavirus, norovirus)
How long does it take for bacterial-mediated infection to cause diarrhoea symptoms?
1-3 days
Which gram negative organism produces a toxin that causes profuse watery diarrhoea and is common in places such as refugee camps?
Vibrio cholerae
What parasite infects animals, causes diarrhoea and can’t be killed by chlorine?
Cryptosporidium
Why is E coli UTI sometimes difficult to eradicate?
Because some E coli bacilli have tails and hooks for hooking onto mucosa
Why does norovirus spread so quickly?
Aerosolised vomit has great infective power
Why should you always wash your hands after coming into contact with a patient who has C diff diarrhoea?
C difficile produces spores that are highly resistant to chemicals and cannot be killed by hand gel.
How would you manage a patient with symptomatic clostridium difficile?
- Isolate patient
- Test stool samples
- Environmental cleaning
- Treat with metronidazole or vancomycin
Are HIV, bird flu and vCJD notifiable diseases?
No
What sorts of diseases are notifiable?
- Diseases that are normally vaccinated against as these tend to be highly transmissible
- Diseases that need specific control measures e.g. acute infectious hepatitis, scarlet fever, TB
- Scary stuff that isn’t endemic to UK e.g. anthrax, cholera, plague, rabies, SARS, smallpox, yellow fever
- Some really serious diseases e.g. brucellosis, HUS (haemolytic uraemic syndrome), legionnaires disease
What are the symptoms of acute hepatitis?
Non-specific symptoms e.g. malaise, lethargy, myalgia
GI upset, abdominal pain
Possibly jaundice, pale stools and dark urine
What are the signs of acute hepatitis?
Tender hepatomegaly +/- jaundice
Signs of fulminant hepatitis (acute liver failure) e.g. bleeding, ascites, encephalopathy
What would LFTs in a patient with acute hepatitis normally show?
Raised transaminases (AST/ALT >> GGT/ALP) \+/- raised bilirubin
What are the possible viral causes of acute hepatitis?
Hepatitis A B+/-D C and E
Herpes, Varicella, Cytomegalovirus, Epstein-Barr
Covid-19
What are the possible non-viral causes of acute hepatitis?
Spirochaetes, mycobacteria, bacteria, parasites
What are the possible non-infective causes of acute hepatitis?
Drugs, alcohol, toxins/poisoning, pregnancy, non-alcoholic liver disease
What are the signs and symptoms of chronic hepatitis?
May have no symptoms or only non-specific symptoms
May have signs of chronic liver disease e.g. spider naevi, palmar erythema, clubbing, Dupuytren’s contracture
If decompensated, may have jaundice, ascites, bacterial peritonitis, encephalopathy, varices…
What would blood results in a patient with chronic hepatitis show?
Transaminases (ALT/AST) can be normal
If compensated, all LFTs can be normal
If decompensated, increased platelets and INR, increased bilirubin, low albumin.
Which viruses cause chronic hepatitis?
Hepatitis B+/-D, C and E
Which individuals are at risk of hepatitis A in developing countries?
Travellers, MSM, IVDU
How is hepatitis A managed?
Supportive management - condition is self-limiting and rarely causes acute liver failure
Monitor liver function just in case (INR, albumin, bilirubin etc), management of close contacts
Which of the 4 genotypes of hepatitis E is found in high income countries?
G3, which is found in undercooked pork products
How is hepatitis E transmitted?
Faeco-oral transmission
Which patients are at risk of chronic infection with hepatitis E?
Immunosuppressed patients e.g. transplant, HIV
How is hepatitis E managed?
Supportive management only for most patients (usually self-limiting). Monitor for liver failure - transplant may be required in some cases.
How can hepatitis E be prevented?
Avoid eating undercooked meats (especially if immunocompromised)
Screening of blood donors
Vaccines (in development)
How is chronic hepatitis E infection managed?
If HEV RNA is present beyond 6 months, reverse immunosuppression if possible, treat with ribavirin as first line treatment, second line treatment PEGylated interferon-alpha
Why are babies and at risk mothers vaccinated against hepatitis B?
Neonates and infants find it more difficult to clear hepatitis B as the immune system is not yet fully developed. Whilst chronic hep B is rare in immunocompetent adults, 90% of infected babies will develop it.
What is the marker for current hepatitis B infection?
Hep B surface antigen
How is acute hepatitis B managed?
Supportive management and monitor liver function - do not use interferon!
Most patients will clear the virus within 6 months
What do the NICE guidelines recommend as first line treatment for chronic hepatitis B?
Pegasys (PEGylated interferon alpha 2a)
What are the risks of Pegasys treatment?
Thyroid disease, type 1 diabetes, lowered white cell count
How is hepatitis D transmitted?
Via blood and bodily fluids - mainly blood products, iatrogenic causes and IVDU
How would you test for hepatitis D?
Check for hep D antibody first; if positive, test for HDV RNA
How is hepatitis D treated?
Pegasys (PEGylated interferon alpha) for 48 weeks
Which type of hepatitis virus will normally progress to chronic infection?
Hepatitis C
What is the greatest risk factor for hepatitis C in the UK?
IV drug use
Name some of the fancy new drugs that can be used to treat hepatitis C
NS3/4A inhibitors: glecaprevir/grazoprevir
NS5A inhibitors: pibrentasvir/elbasvir
Maviret contains glecaprevir and pibrentasvir
Zepatier contains elbasvir and grazoprevir
What causes gastritis/stomach ulceration?
Destruction of the neutral mucin layer (e.g. due to ischaemia) in the stomach, which results in stomach epithelium being exposed to low pH and cells are killed by the stomach acid.
Why is gastric mucosal ischaemia common in patients in cardiovascular shock?
The body sends the blood to more ‘important’ organs, rather than the stomach.
How can NSAIDs cause gastritis?
NSAIDs are not dissolved by the time they get to the stomach and sit on the mucosa, exhibiting a locally corrosive effect due to inhibition of COX2.
Name 5 causes of gastritis.
- H pylori infection
- NSAIDs
- Stress
- Strong alcohol
- Anatomical abnormalities that allow bile reflux into the stomach (corrosive)
What can happen in cases of chronic H pylori infection?
Intestinal metaplasia occurs (intestinal epithelium is more resistant to the effects of H pylori)
What is the treatment for H pylori?
Metronidazole for 1 week
What can eventually happen in cases of severe gastric ulceration?
The ulcer grows, eventually hits a blood vessel and can cause torrential haemorrhage and subsequent haemodynamic shock.
How does malabsorption present?
Change in bowel habits
Weight loss
Iron deficiency anaemia
Why are there lymphocytes on top of the small bowel epithelium?
To protect the epithelium as food is foreign material
Give 5 causes of malabsorption
- Insufficient intake
- Defective intraluminal digestion
- Insufficient absorptive area
- Lack of digestive enzymes
- Defective epithelial transport
Give 4 possible causes of defect intraluminal digestion
- Pancreatic insufficiency (e.g. pancreatitis, CF)
- Biliary obstruction (resulting in defective bile secretion, fats can’t be emulsified, therefore can’t be absorbed)
- Ileal resection (decreased bile salt uptake)
- Bacterial overgrowth (can block intraluminal digestion)
What antibodies are produced by coeliac patients?
Gliadin antibodies
Which parasite (usually acquired by drinking contaminated water) blocks absorption of nutrients?
Giardia lamblia
What procedure, sometimes carried out for morbid obesity, Crohn’s disease or infarcted small bowel, can result in malabsorption?
Small intestinal resection/bypass
What are the two types of idiopathic inflammatory bowel disease?
Crohn’s disease
Ulcerative colitis
What kind of appearance can sometimes be seen in severe cases of chronic Crohn’s disease?
Cobblestoning
Describe the endoscopic appearances of Crohn’s disease
Patchy inflammation with little white ulcers appearing anywhere along the GI tract (from mouth to anus). Inflammation may contain granulomas.
What complications can occur as a result of Crohn’s disease?
Malabsorption (due to inflammation or surgical resections)
Bowel obstruction due to fibrosis and scarring
Perforation and subsequent peritonitis
Fistula formation
Anal skin tags/fissures/fistulas
Amyloid protein (systemic complication)
What part of the GI tract is affected by ulcerative colitis?
The colon mucosa only - extends continuously from the rectum but will not go any further than the caecum. Inflammation doesn’t go any deeper than mucosa - no perforation or granulomas.
What organs besides the colon can be affected by ulcerative colitis?
Liver, joints, eyes and skin
What are functional GI disorders?
A group of disorders classified by GI symptoms related to any of the following: Visceral hypersensitivity Motility disturbances Altered mucosal and immune function Altered CNS processing Altered gut microbiota
Why do some patients with functional GI disorders have mood disorders too?
Because gut-brain interaction runs both ways
Why are women more affected by functional GI disorders than men?
Because of hormonal influence - may also explain, at least partially, why functional GI disorders are more common in young adults
What are the features of IBS?
Chronic frequent abdominal pain
Altered bowel habit (diarrhoea/constipation/both)
Bloating
Why should abdominal bloating always be investigated in women >45?
It could be a sign of uterine/ovarian/endometrial cancer
Name 3 organic conditions that mimic IBS
- Coeliac disease
- Colon cancer
- Inflammatory bowel disease
Why should everyone with IBS have a test for coeliac disease?
Coeliac disease is more common in IBS patients
Name two common functional GI disorders
- Functional dyspepsia
2. Irritable bowel syndrome
What are the ‘alarm features’ that would prompt endoscopic investigation of a patient with GI symptoms?
Age >45 years at onset Short history of symptoms Documented unintentional weight loss Nocturnal symptoms Family history of GI cancer GI bleeding Palpable abdominal mass/lymphadenopathy Evidence of iron deficiency anaemia on blood testing Evidence of inflammation on blood/stool testing
What are the first line investigations for a patient with chronic lower GI symptoms?
FBC, CRP, coeliac serology, faecal calprotectin, stool MC&S
What is stool faecal calprotectin?
A degradation product from neutrophils, which serves as a marker for inflammation.
What do you do with faecal calprotectin results?
FC is normal in IBS but present in IBD
If <50, negligible chance of IBD
If 50-150, repeat in one month
If >150, refer to gastro
What is post infectious IBS?
Lingering GI symptoms following a bout of gastroenteritis - occurs in about 1 in 10 patients and more common in those with adverse life events or history of depression/anxiety.
What drug can sometimes be prescribed for functional GI disorders to help dampen brain-gut connection?
Amitriptyline
What are the functions of the peritoneum in health?
- Visceral lubrication
2. Fluid and particulate absorption
What are the functions of the peritoneum in disease?
- Pain perception
- Inflammatory and immune responses
- Fibrinolytic activity
What is peritonitis?
Inflammation of the peritoneum
How is peritonitis classified
By onset (acute/chronic) and source of origin (primary/secondary)
What causes peritonitis?
- Bacteria
- Chemicals
- Trauma
- Ischaemia
- Miscellaneous causes e.g. familial Mediterranean fever
What conditions can cause peritonitis due to GI perforation?
Perforated ulcer/appendix/diverticulum
What conditions can cause peritonitis via transmural translocation?
Pancreatitis, ischaemic bowel, primary bacterial peritonitis
What other possible routes for peritoneal infection are there apart from perforation and transmural translocation?
Exogenous contamination (e.g. drains, open surgery, trauma, peritoneal dialysis) Female genital tract infection, e.g. pelvic inflammatory disease Haematogenous spread (rare) e.g. septicaemia
What GI microorganisms can cause peritonitis?
- E coli
- Streptococci
- Enterococci
- Bacterioides
- Clostridium
- Klebsiella pneumoniae
What are the clinical features of localised peritonitis?
- Signs and symptoms of underlying condition
- Pain
- Nausea and vomiting
- Fever
- Tachycardia
- Localised guarding
- Rebound tenderness
- Shoulder tip pain
- Tender rectal and/or vaginal examination
What are the early clinical features of diffuse (generalised) peritonitis?
- Abdominal pain made worse by breathing/moving
- Generalised guarding
- Infrequent bowel sounds, which may stop altogether (paralytic ileus)
- Fever
- Tachycardia
What are the late clinical features of diffuse (generalised) peritonitis?
- Generalised rigidity
- Distension
- Absent bowel sounds
- Circulatory failure
- Thready, irregular pulse
- Hippocratic face
- Loss of consciousness
What investigations are carried out for peritonitis?
- Urine dipstick to check for UTI
- ECG if in doubt as to cause of abdominal pain
Bloods: U&E, FBC, serum amylase, group and save
How is peritonitis managed conservatively?
- Correction of fluid loss and circulating volume
- Urinary catheterisation +/- gastrointestinal decompression
- Antibiotics
- Analgesia
How is peritonitis managed surgically?
Depending on cause
- Remove/divert cause e.g. repair perforated ulcer, excise perforated organ
+/- drainage
- Peritoneal lavage
Name 5 special forms of peritonitis
- Bile peritonitis
- Spontaneous bacterial peritonitis
- Primary pneumococcal peritonitis
- Tuberculous peritonitis
- Familial Mediterranean fever (periodic peritonitis)
What is ascites?
An accumulation of excess serous fluid within the peritoneal fluid
How much fluid should a healthy adult have in the peritoneal cavity?
Men - no fluid
Women - up to 20ml
How is ascites classified?
Classified into 4 stages:
Stage 1: Detectable only after careful examination/USS
Stage 2: Easily detectable but relatively small volume
Stage 3: Obvious, but not tense ascites
Stage 4. Tense ascites
What is tense ascites?
When the abdomen becomes distended and painful
How do we check whether ascites is transudative or exudative?
Measuring protein concentration. <25g/l = transudative, >25g/l = exudative
What are the causes of transudative ascites?
- Low plasma protein concentrations due to malnutrition, nephrotic syndrome, protein-loss enteropathy
- High central venous pressure due to congestive cardiac failure
- Portal hypertension due to portal vein thrombosis/cirrhosis
What are the causes of exudative ascites?
- Peritoneal malignancy
- Tuberculous peritonitis
- Budd-Chiari syndrome
- Pancreatic ascites
What accounts for 75% of ascites cases?
Liver cirrhosis
How does ascites present?
- Abdominal distension
- Nausea, loss of appetite
- Constipation
- Cachexia (wasting syndrome)
- Pain/discomfort in case of malignant causes
- Other symptoms associated with underlying cause e.g. jaundice
How is ascites investigated?
- Investigate underlying cause (e.g. LFTs, cardiac function)
- Imaging (x-ray if at least 500ml, USS if 200-500ml, CT abdomen if smaller amount)
- Ascitic aspiration under imaging guidance
- Fluid for microscopy, cytology, culture, analysis of protein content and amylase
How is ascites treated?
- Treatment of specific cause e.g. TIPS procedure
- Sodium restriction
- Diuretics
- Paracentesis (up to 4-6l/day with colloid replacement)
- Indwelling drain (for home paracentesis, useful for smaller volumes)