Gastroenterology Flash Cards
(119 cards)
Achalasia (features, investigations, therapeutic options).
Impaired lower oesophageal sphincter relaxation and peristalsis in distal oesophagus.
Chronic, often constant, dysphagia for solids and liquids.
Weight loss unusual unless end-stage disease.
Increased risk of SCC x 10.
Investigations - barium swallow, endoscopy, oesophageal manometry.
Therapeutic options:
- calcium channel blockers, ISM.
- peroral endoscopic myotomy (POEM) * preferred.
- pneumatic dilatation (PD).
- oesophagectomy.
- endoscopic botox injection.
Eosinophilic Oesophagitis.
Younger patients; male > female.
- Food bolus obstruction.
- Chronic dysphagia solids > liquids.
- Refractory GORD.
Infiltration of eosinophils into oesophageal mucosa (15/hpf).
Therapeutic options:
1. PPI therapy - lack of evidence; usually high-dose for 8 weeks.
2. Swallowed topical steroids - eg budesonide 1mg orodispersive tablets.
3. Dietary elimination - difficult.
Barrett’s Oesophagus.
Risks: male, Caucasian, overweight, age, chronic heartburn, smoking, positive family history.
Precursor to oesophageal adenocarcinoma.
Risk of progression 0.38% per year.
Medical therapy: evidence to suggest combination PPI and aspirin therapy reduces risk of cancer development (AspECT trial).
Barrett’s Surveillance - confirmed LGD / HGD.
If LGD confirmed on 2 occasions 6 months apart by two expert pathologists -> endoscopic ablation therapy (or close surveillance).
If HGD confirmed, annual risk of progression to adenocarcinoma is 10%. Oesophagectomy vs. endoscopic resection preferred to ablative techniques.
Post-removal of HGD, need to treat the remainder of Barrett’s and RFA preferred.
Malignant and Benign Features of Dysphagia.
Malignant:
- Shorter duration.
- Solids > liquids.
- Constant and progressive.
- Older age.
- Accompanying alarm symptoms.
Benign:
1. Often long history.
2. Liquids + solids.
3. Intermittent/unpredictable.
4. Younger -> can have alarm symptoms e.g. weight loss, but this is often late in the clinical course.
(DDx: eosinophilic oesophagitis, achalasia, other dysmotility, benign stricture, globus hystericus).
Oesophageal Cancer Types.
- Squamous cell carcinoma.
- 90% oesophageal cancer worldwide.
- Male:female 1:1.
- Associations: smoking, alcohol, 10x more likely in achalasia.
- Most commonly in mid-oesophagus. - Adenocarcinoma.
- Most common oesophageal cancer in N. America and Europe.
- Male:female 3-4:1.
- Associations: GORD, obesity, no link to alcohol.
- Lower oesophageal distribution.
Endoscopic Features of Benign and Malignant Ulcers.
Benign:
- Round/oval/punched out, flat, smooth base.
- Smooth margins and normal surrounding mucosa.
- Majority <2cm.
- Normal adjoining rugal margins that extend to margins of the ulcer base.
Malignant:
- Irregular outline with necrotic or haemorrhagic base.
- Irregular raised margin.
- Anywhere.
- Any size.
- Prominent and oedematous rugal folds that usually do not extend to the margins.
H. pylori and disease.
<20% of those infected develop symptoms. PUD: ~10% of infected patients. Gastric Ca.: 1-3% of infected patients. MALT lymphoma: <0.1% infected patients. BUT - HP gastritis in 80% of patients with gastric cancer. - HP in 95% MALT lymphoma.
H. pylori and peptic ulcer disease.
75% of duodenal ulcers are associated with HP; eradication heals 95-98% compared with 85-95% with acid suppression alone.
HP infection associated with 70-80% gastric ulcers, 85% heal with HP eradication.
In upper GI bleeding from peptic ulcers, 27-37% will suffer a a re-bleed annually without HP eradication.
H. pylori therapy.
Increased clarithromycin resistance.
Triple therapy should not be prescribed unless H. pylori clarithromycin resistance rates are known to be <15%.
If clarithromycin resistance rates are not known, do not use triple therapy.
First-line if clarithromycin resistance >15% or unknown:
- Quadruple therapy with clarithromycin + metronidazole + amoxicillin + PPI.
- Treatment duration: 14 days.
Post-eradication H. pylori testing.
Everyone.
No sooner than 4 weeks after completion of treatment.
If repeat endoscopy is clinically unnecessary - urea breath test or faecal antigen testing is acceptable.
Pre-breath test: withhold antibiotics for >28 days, withhold PPI for 7-14 days.
Pre-faecal antigen test: withhold PPI 14 days.
Guidelines on anti-platelet agents in high-risk patient with GI bleed.
Restart APA on day 3 post-endoscopy -> relook gastroscopy up to discretion of endoscopist.
If DAPT -> continue aspirin; clopidogrel/ticagrelor continuation/resumption decided on case-by-case basis with cardiologist. If low-risk stigmata, single or DAPT can continue.
Warfarin and GI Bleed.
Scope when INR = 2.5.
Don’t delay to correct coagulopathy.
If INR supra-therapeutic - no evidence. Therefore, partial or complete reversal indicated in cases of serious/life threatening bleeding.
If risk of reversal very high and bleed not severe - delaying endoscopy may be reasonable option.
DOAC and GI Bleed.
If patient stable/responds to resuscitation, reasonable to delay 12-24 hours.
If persistently hypotensive:
a) Dabigatran -> Idarucizumab.
b) Xa inhibitors
- Andexanet alpha (US).
- Combination of clotting factors have been used (PCC/4F PCC).
Resumption same as warfarin.
Coeliac Testing.
Anti-TTG
- Test of choice provided patient consuming gluten-containing diet and sufficient IgA.
If anti-TTG IgA weakly positive, anti-endomysial IgA.
- Very specific but technically difficult test.
In IgA deficiency -> use IgG tests.
** must always test for IgA deficiency.
Refractory Coeliac Disease (subtypes).
Type 1 (85%)
- Lymphocyte infiltrate is the same as that in untreated CD.
- Steroids +/- steroid-sparing agents e.g. azathioprine.
- ?budesonide, ?mesalazine.
Type 2 (15%)
- CD3 intra-epithelial T cells with abnormal surface markers /- oligoclonal T cell expansion.
- Less favourable prognosis.
- Malnutrition can be profound, may need TPN.
- Multitude of therapies tried -> best evidence for Cladribine (chemotherapy used in haematological malignancies).
Whipple’s Disease.
Triad: weight loss, chronic diarrhoea (which can be bloody), arthralgia.
+ prolonged fever and peripheral lymphadenopathy.
SB biopsy shows PAS-positive macrophages in sub-mucosa.
Jaundice (DDx).
- Elevated haeme load.
- Haemolysis.
- Inadequate erythropoiesis.
- Haematoma. - Hepatocellular dysfunction.
- Hepatitis.
- Hepatic failure.
- Cirrhosis.
- Drug injury. - Biliary obstruction.
- Malignant.
- Parasitic.
- Stone disease.
- Extrinsic compression.
Screening for HCC in Cirrhosis.
USS + AFP 6-monthly.
Cutaneous and extremity manifestations of cirrhosis.
Increase in estradiol:
- spider angiomas.
- gynecomastia.
- feminization: inversion of male pubic hair pattern, loss of axillary or chest hair.
- palmar erythema (central palmar sparing).
- testicular atrophy.
Jaundice.
Nail changes: terry nails, muehrchke nails, clubbing.
Hypertrophic osteoarthropathy.
Dupytren’s contractures.
Physical Findings of Cirrhosis.
Parotid gland enlargement (alcohol). Fetor hepaticus. Ascites. Caput medusae. Splenomegaly. Cruveilhier-Baumgarten murmur. Asterixis.
Hepatic Encephalopathy (staging, features).
Reversible neuropsychiatric abnormalities associated with liver dysfunction and/or portosystemic shunting.
Staging:
- Minimal.
- Grade 1: sleep/wake reversal, change in behaviour, mild confusion..
- Grade 2: lethargy, moderate confusion.
- Grade 3: stupor, arousable, incoherent.
- Grade 4: unresponsive to pain, intubate.
Hyperreflexia, bradykinesia, myoclonus, rigidity, nystagmus, decerebrate posturing, focal neurological defects.
NB: caused by ammonia penetration into the CNS. A healthy liver clears ammonia by conversion to glutamine. Measurement of venous ammonia is often not helpful. Not useful prognostically.
Causes of Hepatic Encephalopathy.
Infection.
Bleeding.
Medication - anticholinergics, narcotics/benzodiazepines.
Metabolic derangement - alkalosis, hypokalaemia, hyponatraemia.
Hypovolaemia/hypoxia.
Constipation.
Treatment of Hepatic Encephalopathy.
Lactulose.
- decrease GI transit time.
- decrease pH of gut lumen, trapping NH4.
- alternative metabolic substance for gut bacteria - less ammonia production.
- 30-45mL 2-4 times per day.
- goal is 2-3 soft stools per day.
Rifaximin.
- 400mg tds or 550mg bd.
- novel antibiotic - decontamination of the gut.