Gastroenterology Flashcards
How do you make a diagnosis of C diff infection and how do you determine severity?
Diagnose by detecting CDT (toxin) in stool
WCC to determine severity
Risk factors for C diff?
abx and PPIs
esp cephalosporins
What is the tx stepladder for C diff infections?
first-line therapy is oral vancomycin for 10 days
second-line therapy: oral fidaxomicin
third-line therapy/ in life- threatening cases: oral vancomycin +/- IV metronidazole
What drugs must be stopped before a urea breath test?
no antibiotics in past 4 weeks, no antisecretory drugs (e.g. PPI) in past 2 weeks
What is achalasia?
Most important diagnostic test?
What cancer does it increase the risk of?
How is it treated?
Definition: Failure of oesophageal peristalsis and of relaxation of the lower oesophageal sphincter (LOS) due to degenerative loss of ganglia from Auerbach’s plexus i.e. LOS contracted, oesophagus above dilated.
Presents with dysphagia of both solids and liquids from onset
Key test: Oesophageal manometry
- also shows grossly expanded oesophagus, fluid level and ‘bird’s beak’ appearance on barium swallow
increases the risk of squamous cell carcinoma of the oesophagus
First line: pneumatic (balloon) dilation
Surgical management when comorbidites/recurrence : Heller cardiomyotomy
How is appendicitis diagnosed?
Thin young male patients with a high likelihood of appendicitis (classic central abdominal pain that localises to the right iliac fossa) can be diagnosed clinically w/o a scan
Often do an USS in women for pelvic pathology
Raised inflammatory markers (e.g. CRP) and neutrophil predominant leucocytosis can aid in diagnosis
May be psoas sign positive- unable to stand on one leg comfortably and pain on hip extension
Best way to measure liver function in people with established disease?
Liver enzymes are a poor way to look at liver function - they are usually low in end-stage cirrhosis whereas coagulation e.g. prothrombin time and albumin are better measures
What is fetor hepaticus?
sweet and fecal breath, it is a sign of liver failure
Causes of acute liver failure?
paracetamol overdose
alcohol
viral hepatitis (usually A or B)
acute fatty liver of pregnancy
Features of acute liver failure?
jaundice
coagulopathy: raised prothrombin time
hypoalbuminaemia
hepatic encephalopathy
renal failure is common (‘hepatorenal syndrome’)
Raised urea + normocytic anaemia= ?
How much does urea need to be raised to be a significant case?
Upper GI bleed!
- a haemorrhage with an origin proximal to the ligament of Treitz
Urea is from protein meal (digestion of RBCs)
Urea of 15.4 mmol/l on a background of normal renal function is a significant bleed
Management of Upper GI bleed?
All patients with suspected upper GI bleed require an endoscopy within 24 hours of admission
IV PPIs given AFTER endoscopy (never before) if evidence of recent variceal haemorrhage
Repeated endoscopic intervention with no success (more acute bleeds) = surgical intervention
How is risk stratified in Upper GI bleeding?
the Glasgow-Blatchford score used at first assessment
helps clinicians decide whether patient patients can be managed as outpatients or not
the Rockall score is used after endoscopy
provides a percentage risk of rebleeding and mortality
Eq for alcohol units?
Alcohol units = volume (ml) * ABV / 1,000
Cause of metabolic acidosis in non-diabetic alcoholics? Tx?
Alcoholic ketoacidosis
- Often alcoholics will not eat regularly and may vomit food that they do eat, leading to episodes of starvation and ketone production
Will likely have normal or low blood glucose
treatment is an infusion of saline & thiamine
AST/ALT ratio in alcoholic hepatitis?
2:1
Management of alcoholic hepatitis?
glucocorticoids (e.g. prednisolone) are often used during acute episodes of alcoholic hepatitis
Maddrey’s discriminant function (DF) is often used to determine who would benefit from glucocorticoid therapy
- its calculated using prothrombin time and bilirubin concentration
pentoxyphylline is also sometimes used
Key investigation in unwell patient taking aminosalicylates?
A patient who is taking aminosalicylates and becomes unwell with a sore throat, fever, fatigue or bleeding gums needs an urgent full blood count to rule out agranulocytosis.
What do Anti-nuclear antibodies (ANA) and/or anti-smooth muscle antibodies (SMA) with raised IgG suggest?
Type 1 autoimmune hepatitis- common in young women, often also see secondary amenorrhea, tx with steroids
When is endoscopic intervention ( endoscopic mucosal resection or radiofrequency ablation) offered with Barrett’s oesophagus?
When dysplasia is seen
If not pts can be managed with endoscopic surveillance every 3-5 years and a high dose PPI
how does Budd-Chiari present and how is it investigated?
Budd-Chiari syndrome (hepatic vein thrombosis):
Presents with the triad of sudden onset abdominal pain, ascites, and tender hepatomegaly
Can do a Serum - Ascites Albumin Gradient (a raised SAAG (>11g/L) indicates that it is portal hypertension that has caused the ascites and makes Budd-Chiari more likely)
Investigate with doppler USS
For carcinoid syndrome (release of serotonin into systemic circulation), outline the presentation, test and tx
carcinoid syndrome-
Sx: flushing, diarrhoea, bronchospasm, hypotension, and weight loss
Caused by lung carcinoid or more commonly mets in the liver
Test urinary 5-HIAA
Give somatostatin analogues e.g. octreotide
Features of coeliac?
Coeliac disease:
- non specific symptoms like fatigue, anaemia and weight loss
- low ferritin/folate
- raised white cells/CRP due to inflammation
- raised tissue transglutaminase (TTG) antibody
- grey frothy stool
Coeliac disease increases the risk of developing enteropathy-associated T cell lymphoma
How long before testing should coeliac patients eat gluten? What is being tested for in serology?
6 weeks
tissue transglutaminase (TTG) antibodies (IgA)
How is disease progression monitored in Crohn’s and how is it managed?
ESR can be used to assess disease progression
first-line management strategy for the induction of remission is glucocorticoids
Azathioprine or mercaptopurine is used first-line to maintain remission
Managing complications:
MRI is the investigation of choice for suspected perianal fistulae- provides visualisation of the course
Wound swab can be used for recurrent abscesses
Management of ‘undiagnosed’ dyspepsia?
Patient with dyspepsia who does not meet referral criteria:
do a full work up before anything else e.g bloods and review meds for common drug-induced causes such as NSAIDs and aspirin
give lifestyle advice
trial PPI for one month
If PPI fails for reflux and upper GI symptoms test for H.pylori
When is urgent referral required for dyspepsia?
All patients who’ve got dysphagia
All patients who’ve got an upper abdominal mass consistent with stomach cancer
Patients aged >= 55 years who’ve got weight loss, AND any of the following:
upper abdominal pain
reflux
dyspepsia
What tests are needed in a pt with GORD being considered for surgery?
oesophageal pH and manometry studies- measures pressure in oesophageal sphincter to confirm diagnosis
Sign on biopsy in gastric cancer?
Signet ring cells - more = worse prognosis
What is Gilbert’s syndrome and how does it present?
autosomal recessive condition of defective bilirubin conjugation due to a deficiency of UDP glucuronosyltransferase
An isolated rise in bilirubin in response to physiological stress (e.g. onset of jaundice exclusively while ill, exercising or fasting) is typical
No treatment required
Describe presentation, investigation and management of hereditary haemochromatosis
Haemochromatosis : aut. dom. disorder of iron absorption
Presentation:
bronze/ slate grey colouration
fatigue and cognitive sx
joint pain - can have secondary osteoarthritis (hook-like osteophytes at the 2nd and 3rd digits at MCPJ)
hair loss
erectile dysfunction
Investigation:
general population: transferrin saturation > ferritin
family members: HFE genetic testing
(can also do liver biopsy w Perl’s stain)
Management:
venesection
Ferritin and transferrin saturation are used to monitor treatment
Describe presentation and tx of hepatic encephalopathy
Hepatic encephalopathy:
Liver disease -> build up of ammonia and glutamine ( liver cell impairment prevents adequate metabolism and portosystemic anastomoses mean blood can bypass the liver altogether)
Presentation: altered GCS, acute confusion, asterixis (hepatic flap) and triphasic slow waves on ECG
Graded 1- 4 : Irritability -> confusion -> incoherence -> coma
Tx: lactulose first line to excrete ammonia , then rifaximin to alter gut flora and breakdown of ammonia there
What is indicated by:
1. HBsAG
2. Anti-HBc
3. Anti-HBc IgM
4. Anti-HBc IgG
5. Anti-HBs
6. HbeAg
- first surface antigen to be produced in response to infection, represents acute hepatitis infection if less than 6mo or chronic if present for over 6mo. If it is negative they are not currently infected.
- anti hepatitis core antibody is produced in response to infection- c for caught- currently or has previously caught hepatitis
- IgM- acute infection
- IgG- chronic infection, remains indefinitely even if hepatitis is cleared (IgM are produced in initial infection and are gradually replaced with IgG over months)
- immunisation (in a healthy individual who has been vaccinated this is the only one that is raised)
- results from breakdown of core antigen from infected liver cells. Marker of HBV replication and infectivity
What is the Sister Mary Joseph node?
a palpable nodule in the umbilicus due to metastasis of malignant cancer within the pelvis or abdomen
Describe the nature of hepatomegaly in:
Early cirrhosis
Malignancy
RHF
Hepatomegaly:
Cirrhosis (in early disease): Associated with a non-tender, firm liver
Malignancy: metastatic spread or primary hepatoma. Associated with a hard, irregular liver edge
Right heart failure: firm, smooth, tender liver edge. May be pulsatile
Most common disease pattern in UC and Crohn’s?
UC- proctitis
Crohn’s- ileitis
Tx of IBS?
IBS Tx:
pain: antispasmodic agents
constipation: laxatives but avoid lactulose ( first line isphagula husk, linaclotide can be used as an alternative to conventional laxatives if nothing else works for 12 months)
diarrhoea: loperamide is first-line
Features and test for acute mesenteric ischaemia (occlusion of blood flow to small bowel)
Common features
abdominal pain - often of sudden onset, severe and not inkeeping with physical exam findings
fever
rectal bleeding and diarrhoea
often have a hx of AF
Investigation:
Venous blood gas first line to look for raised lactate
What is ischemic colitis? Sign on Xray?
Transient compromise in blood flow to large bowel
Often occurs in watershed areas like splenic flexure
Thumb-printing seen on xray
Give 3 causes of liver cirrhosis. Investigation of choice?
Causes:
alcohol
non-alcoholic fatty liver disease (NAFLD)
viral hepatitis (B and C)
Transient elastography is now the investigation of choice
What is Melanosis coli?
Melanosis coli is the abnormal pigmentation of the large bowel due to the presence of pigment-laden macrophages. It is most commonly due to laxative abuse
Briefly differentiate between Mallory Weiss, Plummer Vinson Syndrome and Boerhaave Syndrome
Mallory-Weiss syndrome
Severe vomiting → painful mucosal lacerations at the gastroesophageal junction resulting in haematemesis. Common in alcoholics
Plummer-Vinson syndrome:
triad of dysphagia, glossitis and iron-deficiency anaemia
(dysphagia is due to post cricoid webs)
tx is iron supplements and dilation of webs
Boerhaave syndrome:
Severe vomiting → oesophageal rupture
Chest pain and subcut emphysema also feature
key investigation for a suspected perforated peptic ulcer?
Erect CXR to look for pneumoperitoneum
Difference between duodenal and gastric ulcers?
Duodenal ulcers characteristically cause pain when hungry, and are relieved by eating
Gastric ulcers are worse with food
Outline presentation and tx of pernicious anaemia
Pernicious anaemia: autoimmune disorder that causes B12 deficiency
antibodies to IF
middle/old age patients, more common in females
anaemia features (headache, fatigue, pallor)
neuro features - peripheral neuropathy, psychiatric changes
Can have pancytopenia
Tx= IM Vit B12
Vitamin B12 1mg IM three times/week then 1mg IM every 3 months
folate should never be replaced before vitamin B12 due to the risk of precipitating subacute combined degeneration of the cord. (Think BeFore: B before F to remember).
What is Peutz Jehgers syndrome?
Aut. dom condition
Hamartomatous polyps in GI tract (often presents with small bowel obstruction)
Pigmented freckles on lips, palms and soles
Dysphagia, aspiration pneumonia, halitosis (bad breath) →
pharyngeal pouch
Investigate with barium swallow
Outline presentation and management of primary biliary cholangitis
Chronic autoimmune condition, bile ducts damaged by inflammation, often presents with itching or jaundice or raised ALP on routine bloods
Imaging required to rule out extra-hepatic biliary obstruction
Management : ursodeoxycholic acid 1st line, then cholestyramine for itching
What is SBBO? Give risk factors, diagnostic test and tx.
Small bowel bacterial overgrowth syndrome:
excessive bacteria in SI
presents w chronic diarrhoea and flatulence
scleroderma and diabetes are risk factors, as well as neonates w congenital GI issues
hydrogen breath test to diagnose
treat with rifaximin
For SBP, give the presentation, diagnostic test and tx.
Features:
ascites, abdominal pain, fever
Diagnosis is by paracentesis. Confirmed by neutrophil count >250 cells/ul
Managed with IV cefotaxime (E.coli infection)