Gastroenterology Flashcards
Definition Barretts
Classical > 3cm +/- Tongues
Prague Criteria for Barretts
C - degree circumferential disease
M - Maximal Barrett oesophagus segment length
For example, Barrett oesophagus extending circumferentially for 2 cm above the squamocolumnar junction but with tongues of Barrett oesophagus extending 5cm = C2M5.
Surveillance Barretts
Risk of progression to adenocarcinoma
- 5% if nil dysplasia; 3-5 year surveillance
- 7% Low-grade dysplasia, 6 monthly surveillance
7% High-grade dysplasia for surgery (or ablation if not fit for surgery)
SBP Diagnosis
Leuks > 500, with > 250 neutrophils
If predominantly lymphocytes > neutrophils, consider diagnosis of peritoneal carcinomatosis or Tb
Definition Hepatorenal syndrome
Relative lack of circulatory volume due to pooling in splanchnic blood flow
- Serum Cr > 133, without improvement with volume expansion & cessation of diuretics
- Urine Na < 20, no proteinurea
- Absence of other causes - new nephrotoxic drugs, shock
Types
Type 1; acute - x 2 baseline Cr over 2 weeks without improvement with volume expansion, diuretics or cessation of nephrotoxic drugs **expedite referral for transplant**
Type 2; slow and indolent progression with diuretic resistant ascites
HNPCC
Cancer with NO POLYPS- a patient with have a finding of colon cancer on scope, but the rest of the colon will be normal without polyps
Associated with microsatellite instability
Associated with MSH2 (60%) -“S for second & serious”, MLH1 (30%) gene mutation which are DNA mismatch repairs.
Most commonly cancer of the proximal colon
Associated with high risk of endometrial (80% lifetime risk), ovarian, stomach, small intestine, hepatobiliary, urinary tract, brain and skin cancers.
Kings criteria for Liver Transplant (Paracetamol Overdose)
“Acute PCM”
- Acidosis
- Prothrombin time > 100, INR > 6.5
- Cr > 300
- Mental state reduced, encephalopathy grade 3-4
Kings criteria for Liver Transplant (Not Paracetamol Overdose)
Prothrombin time > 100, INR > 6.5
OR, any 3 of;
- Non Hep A/B viral hepatitis, drug induced or indeterminate aetiology
- Time from jaundice to encephalopathy > 7 days
- Age < 10, > 40
- Prothrombin time > 50, INR > 3.5
Serum Bili > 17
Autoimmune Hepatitis
Commonly young females
Type 1
- associated with Autoimmune conditions (SLE, T1DM, UC, Coeliacs, Vasculitis)
- Anti-Smooth muscle Ab positive
Type 2
- Anti -Liver-kidney-microsomal Ab → Anti- LKM1
- High IgG (hypergammaglobinaemia)
Requires lifelong immunosuppression i.e. Pred or Azathioprine
Hep C treatment
If no cirrhosis, or pregnant - Maviret - “M for Mum”
- Glecaprevir (protease inhibitor)
- Pibrentasvir (NS5A inhibitor)
If cirrhotic - Epclusa “C for cirrhosis”
- Velpatasvir (NS5a inhibitor)
- Sofosbuvir (Nucleoside RNA polymerase inhibitors)
H.Pylori treatment
Triple therapy
Amoxicillin
Clarithromycin, or Metronidazole if sensitivity available
PPI
SALVAGE
- Levofloxacin triple therapy
Amoxicillin
Levofloxacin
PPI - Quadruple therapy
Bismuth salt
Tetracycline
Metronidazole
PPI - Rifabutin triple therapy
Amoxicillin
Rifabutin
PPI
CAG A = gastric
CAG B = duodenal
Proof of cure with C13 Urea breath test, faecal antigen or biopsy, at least 4 weeks after treatment. Serologic testing is not used to confirm H. pylori eradication because it can remain positive in the absence of active infection.
Leptin
Appetite suppressant and increases energy expenditure
At the arcuate nucleus of hypothalamus
- inhibits neurotransmitters; Neuropeptide Y & Agouti-related peptide
- Stimulates neurotransmitters; POMC a& MHC
Liver transplant criteria HCC
Single lesion 1- 5cm lesion
< 3 lesions, < 3cm in size
No metastatic disease
Contraindications to Liver transplant
- Morbid obesity > 40 BMI
- Current EtOH intake - abstinence 3-6 months
- Cardiopulmonary disease
Child Pugh Score
ABCDE
Albumin
Bilirubin
Coagulation
Drain or dullness (for ascites)
Encephalopathy
Crohns extra-intestinal manifestations that don’t correlate with disease activity
Pyoderma gangrenous
Primary sclerosing cholangitis
Small joint and axial arthritis
Uveitis
Crohns extra-intestinal manifestations that correlate with disease activity
Episcleritis
Large joint Arthritis
Erythema Nodosum
Apthous Ulcers
Crohns genetic predisposition
Nod2/CARD15 gene variants
- worse phenotype
- associated with early initial surgery due to stricturing disease and surgical recurrence in Crohn’s disease
pANCA negative, ASCA positive
Coeliac genetic predisposition
HLA DQ 2/8
Ustekinumab
Anti -IL 12 and 23 for psoriasis and associated peripheral arthropathy & inflammatory bowel disease
Serological markers IBD
- pANCA -, ASCA + = Crohns
- pANCA +, ASCA - = UC
Vedolizumab
Treatment IBD
Vedolizumab; alpha4, beta7 integrin receptor inhibitor
Prevents inflammatory cells translocating into gut
Gut specific - does not work for extra-intestinal manifestations
Safest, give to travellers to Tb endemic areas, elderly and cancer patients
Hep B in pregnancy
- Tenofovir in third trimester if VL > 10^5, but stop in postpartum period
- Vaccination
- Hep B immunoglobulin & vaccination given to baby within 12 hours
- Reduces risk of vertical transmission by 95%
- Breast feeding does not increase risk!
Causes of B12 deficiency
Pernicious anaemia
- Anti-IF Ab (specificity 100%)
- Anti-parietal cell Ab
- Elevated gastrin
- Low pepsinogen I, low ration pepsinogen I: II Terminal ileum disease
Gastrectomy
Pancreatic insufficiency
Veganism
Atrophic gastritis
Small bowel bacterial overgrowth
Neomycin blocking agents
Metformin
Nutrient absorption
B12 deficiency testing
Schilling test
High methylmelonic acid (MMA)
High of Homocysteine
Anti - IF Ab (more specific for perncious anaemia)
Anti- Pariatel cell Ab
Rome 3 Criteria for functional constipation
Types
Colonic inertia - slow transit constipation
Dyssenergic or pelvic floor dysfunction - outlet delay
Diagnosis - Rome 3 criteria, at least 12 weeks in 12 months (does not need to be consecutive);
- Must not meet criteria for IBS
- Must not have alternating constipation and diarrhoea
- Straining > 25% defections
- Sensation of incomplete evacuation/anorectal obstruction > 25% defecations
- Manual manoeuvres for > 25% defecations
- < 3 defecations/week
Coeliac Investigations
Tissue Transglutaminase antibodies (tTG-IgA) with total IgA levels
3% of people will be IgA deficient (20% caucasians) which can cause a false negative, so always measure at same time
De-amidated gliadin peptide (DGP-IgG)
Endomysial antibody (EMA-IgG)
Anti-gliadin antibody (AGA-Iga and IgG)
Coeliac HLA genotyping - HLA DQ2, HLA DQ8 - has good negative predictive value (if negative - likely no coeliac) but poor positive predictive value given present in up to 50% community
Endoscopy with biopsy (histology is gold standard - patients need to be consuming gluten), require at least 2 x biopsy from first part duodenum and 4 x biopsy from second part of duodenum
Azathioprine Side effects
Serum like sickness
Bone marrow toxicity - Before initiation, must test for TPMT enzyme activity
Hepatosplenic T-cell lymphoma > 65 or young males who are EBV seronegative
Non-melanoma skin cancer
Pancreatitis
Hepatitis
Zollinger-Ellison syndrome
- Gastrinoma; Neuroendocrine tumour that secretes gastrin which causes hyper secretion of acid in stomach
- Measure serum gastrin
- Dx with Somatostatin receptor scintigraphy
Transcobalamin II (TCII) deficiency
Autosomal recessive disease marked by defective intestinal absorption of vitamin B12
Causes megaloblastic anaemia with normal serum B12 on testing due to circulating form of B12 being bound to transcoabalamin 1 rather than 2
Treat with massive PO intake B12
Primary Biliary Cirrhosis
Involves women > 45, uncommon under 25
Fibrosis of smaller intrahepatic bile ducts
Anti-mitochondrial Ab positive
Rx with ursodeoxycholic acid or transplant
Complicated by osteomalacia
Primary Sclerosing cholangitis
Fibrosis of the larger bile ducts
Strongly associated with Ulcerative colitis (80%), but progressive despite IBD disease status
Disease complicated by cholangiocarcinoma in 10%.
Ursodeoxycholic acid is not useful - can increase risk of death in high doses
No effective treatment
Colorectal cancer mutations
Colorectal Ca; MMR
Familial adenomatous polypsis; APC- Adenomatous polyposis coli (APC) gene mutation on chromosome 5
HNPCC (Lynch syndrome) - MSH2 (60%) -“S for second most serious”, MLH1 (30%) gene mutation which are DNA mismatch repairs. Associated with microsatellite instability in colon tumor specimens
Contraindications to Peg IFN use in Hepatitis
Used for mild/mod Hep B when coexisting Hep D infection
- Pregnancy and lactation
- Cirrhosis
- Uncontrolled depression, can cause psychiatric disorders!
- Unstable cardiac/pulmonary condition
Dumping syndrome
Early - 15 mins - rapid delivery of hyperosmolar nutrients into gut causing GI symptoms, Vasomotor symptoms and hypoglycaemia
Late - 2-3 hours - Rapid absorption of glucose causing a hyperinsulin state and hypoglycaemia
Hep B serology - Acute, Chronic, Resolved, Vaccinated, Susceptible
- Acute infection < 6 months
- HBsAg +
- HBcAb + IgM
- HBsAb -
- Chronic infection
- HBsAG + > 6 months
- HBcAB + IgG
- HbsAB -
- Resolved infection
- HBsAg -
- HBcAB+ IgG
- HBsAB+ (marker of immunity!)
- Vaccinated
- HBsAg -
- HBcAB -
- HBsAB + (will wain over time, vaccination is titre at > 10 on ONE instance)
- Susceptible
- HBsAG -
- HBcAB -
- HBsAB -
Pre-core Mutant Hep B
A variety of hepatitis B virus that does not produce hepatitis B virus e antigen (HBeAg)
HBsAg+
HBsAb-
HBcAb+
HBeAg-
Induction treatment Crohns
Mild
- Prednisolone
- Budesonide for ill disease
Severe
- Hydrocortisone
- Methyl Pred
- AZA
- 6MP
- MTX
Non responsive
- Infliximab
- Adalilumab
- Vedolizumab
Maintenance Therapy Crohns
- AZA
- 6MP
- MTX
If fistulating
- Infliximab
- Adalimumab
- Vaedolizumab
UC induction
- 5-ASA - oral/rectal combination
- Steroids - oral /rectal
- AZA
- 6-MP
- MTX
If non-response after 3 months
- Infliximab
- Vedolizumab
- Ciclosporin
UC Maintanence
- Oral or Rectal 5-ASA
- Aza
- 6MP
- MTX
If non-responsive
- Infliximab
- Vedolizumab
- Surgery
Definition Portal HTN
pressure > 10mmHg
Liver stiffness > 25
Liver stiffness > 15 with platelets < 150
pressure > 12mmHg at risk of ascites and varicies
Mimics Coeliacs
- Tropical Sprue
- CVID (Manifests as low levels of serum IgG, IgA and IgM with loss of antibody production)
- H pylori
- Crohns
- NSAIDs
- Olmesartan
Eosinophilic Oesophagitis
Young males, Hx Atopy, Oesophageal eosinophils in mid to proximal oesophagus (if distal - more likely GORD)
Does not need to have peripheral eosinophilia
Rx Viscous Glucocorticoids + diet elimination
GORD/pathological reflux
4% time
pH < 4 throughout whole oesophagus (not just distal)
Nocturnal/supine symptoms
Scope only required for caucasian, middle to older obese males
Risk factors for oesophageal SCC
- Smoking
- EtoH
- Asian/African
- Achalasia
- Low SES
- Poor PO hygiene
- Thoracic radiation
- HPV
- non-epidermolytic palmoplantar keratoderma
Plummer Vinson Syndrome
Upper oesophageal web and Fe deficiency
Forrest Criteria
- 1a - ulcer with pulsating bleeding
- 1b - ulcer with non-pulsatile bleeding
- 2a - ulcer with non-bleeding visible vessel
- 2b - ulcer with adherent clot
- 2c - ulcer with hemetin on base
- 3 - clean based
1a - 2b requires admission, IV PPI and re-scope
2c-3 can be discharged on oral PPI after scope
Activation pancreatic enzymes
Trypsinogen to trypsin via brush border enterokinase
Prolipase to lipase via trypsin
Procarboxypeptidase to carboxypeptidase via trypsin
Chymotrypsinogen to Chymotrypsin via trypsin
Proelastase to elastase via trypsin
Types dumping syndrome
Early - 15 minutes- Rapid delivery of nutrients into duodenum with hyperosmolar contents causing release of vasoactive agents, to cause vasomotor symptoms, GI symptoms and hypoglycaemia
Late - 2-3 hours - Rapid absorption of glucose causing a hyperinsulin state and hypoglycaemia
Complication Coeliac Disease
- Hyposplenism (with encapsulated sepsis) - due to autoimmune origin
- Lymphoma
- Malnutrition - osteoporosis, Fe deficiency
- Dermatocytosis Herpatiformis
- Peripheral neuropathy
- CVD due to protective factors of whole grains
- Refractory coeliacs - failure of gluten free diet
IBD Medications
Always Measure Intra-abdominal Vascular Aneurysms (or) Go Under
- ASA
- Mercaptapurine
- Infliximab - Anti-TNF - quickest, best for extra-intestinal manifestations
- Vedolizumab - Alpha-4, Beta2 receptor inhibitors - safest for reactivation, Gut specific
- Adalimumab -Anti-TNF
- Golimumab - Anti-TNF
- Ustekinumab - Targets IL12 & 23 - for psoriasis
Why are Gastrin levels high in pernicious anaemia?
Anti-pariatel Ab downregulate Pariatel cell secretion of HCl causing high pH which upregulates G cells to secrete Gastrin to attempt to stimulate further acid secretion from parietal cells
Management of hepatorenal syndrome
Terlipressin - splanchnic vasocontrictor
Albumin as fluid resus
Bridge to transplant, not curative
