Gastro Flashcards
1
Q
Management SBO
A
Initial
- analgesia
- nil by mouth
- gastric decompression
- dehydration
- > IV fluids
- metabolic alkalosis
- > electrolyte replacement
- ischaemia
- > WCC
- > CRP
- > lactate
- > CT abdo
- early surgical consult
Non operative
- adhesive
- > non op successful in approx 80%
- > higher rate of recurrence with non op
- > gastrograffin with xray 6-24 hours later (failure to reach colon after 24hrs predicts need for surgery)
- > trial of non op no longer than 5 days
- non adhesive
- > treat underlying cause
Operative
- indicated when evidence of bowel compromise
- indicated for surgically correctable causes
- > closed loop
- > volvulus
- > intussusception
- > tumour
- > hernia
2
Q
hep B management
A
acute
- usually supportive
- treatment for
- > protracted course (eg. >4 weeks)
- > severe course (eg. INR >1.5)
- antivirals
- > tenofovir or entecavir
chronic
- decompensated cirrhosis or fulminant hepatitis
- > treated with NRTI’s
- compensated cirrhosis
- > treated with NRTI’s since HCC risk reduced
- immune active phase
- > consider treatment if severe
- > do not treat all, as it may prevent spontaneous remission
- inactive carrier
- > treat immediately when HBeAg negative
- > prevents recurrence
- immunosuppression
- > treat with NRTI’s before immunosuppression
- pregnant women
- > high viral load = treat in 3rd trimester
- HCC
- > treat with NRTI
goals
- treatment usually >5 years
- without cirrhosis
- > HBeAg seroconversion on two tests months apart
- with cirrhosis
- > lifelong treatment
- consolidation period
- > 1 year extra therapy after HBeAg seroconversation
3
Q
microbio and pathogenesis of typhoid
A
Microbio
- classical
- > salmonella enterica serotype typhi
- also
- > salmonella enterica serotype paratyphi (ABC)
Inoculation
- typically contaminated
- > water for typhi
- > food for paratyphi
- humans only known resovoir
- > so infection = sick contact
GI infection
- survives acidic stomach and enters small bowel
- enters submucosa
- > via antigen sampling M cells
- > direct penetration into/around epithelial cells
- proliferate in sumucosa
- recruitment of immune cells
- > hypertrophy of peyers patches
- > subsequent perforation of submucosal tissue
- > abdo pain and possible ileal perforation
- release of typhoid toxin
- > causes many of enteric fever symptoms
Systemic spread
- dissemination from peyer’s patches via blood/lymph
- reaches reticuloendothelial system in
- > spleen
- > liver
- > bone marrow
Chronic carriage
- shedding organism in stool or urine >12 months
- gall bladder colonised
- > organism produces biofilm when exposed to bile
- > gall stones provide nidus for chronic infection
- immunological equilibrium
- > contagious
- > no symptoms
4
Q
Clinical features typhoid
A
Inoculation
- contaminated food or water
- travel to endemic areas
Incubation
- 1-3 weeks following ingestion
Signs/Symptoms
- first week
- > rising stepwise fever
- > chills
- second week
- > abdo pain
- > rose spots on trunk
- > bradycardia
- third week
- > hepatosplenomegaly
Other features
- diarrhoea/constipation equally common
- headache common
- neurological findings can occur
- typhoid encephalopathy
- > altered level of consciousness/delirium
- cough
- arthralgia/myalgia
Complications
- ileal perforation
- > peritonitis
- > intestinal bleeding
- sepsis/septic shock
5
Q
Diagnosis typhoid
A
FBC
- anaemia
- leukopaenia or leukocytosis
LFTS
-transaminitis
Stool culture
- least sensitive test
- > often negative by time of presentation
Blood culture
- slightly more sensitive than stool
- > still poor
- several culture tubes needed
Bone marrow
- high sensitivity
- > even after days of antibiotic treatment
6
Q
Risk factors and types of hernias
A
risks
- non modifiable
- > male
- > age
- > family history
- > connective tissue disease
- > chronic cough (COPD)
- > prematurity
types
- inguinal
- femoral
- egigastric
- umbilical/para
- incisional
- spigelion
- > between rectus and semi lunar line
- hiatus
7
Q
Investigation and management hernias
A
investigations
- FBC
- > WCC with necrosis
- EUCs
- > eGFR
- > electrolytes
- ultrasound
- CT for obstruction
- > transition point
- > aetiology
- Xray
- > less sensitive and specific
management
- incarcerated/strangulated
- > surgical repair (lap/mesh)
- small asympto
- > watchful waiting
- large or sympto
- > open or lap mesh
8
Q
X-ray small vs large bowel obstruction
A
3,6,9 rule
- 3 = small
- 6= colon
- 9 = caecum
small
- central
- <3cm
- mucosal folds (valvulae coniventes)
- > fully traverse
- > closely spaced
large
- peripheral
- <6cm
- <9cm for caecum
- haustra folds
- > dont fully traverse
- mottled appearance
- > due to faeces
obstruction
- dilated loops of bowel
- air fluid level
9
Q
cirrhosis pathology
A
cirrhosis
- chronic hepatic insult activates stellate cell
- > accumulation of collagen in parenchyma and space of disse
- in space of disse = capillarisation
- > lose of sinusoid fenestration
- capillarisation and stellate cell contraction
- > increases portal pressure
- overall, fibrosis with regenerative nodules
- > fibrosis may decrease with removal of insult/treatment
10
Q
alcoholic liver disease pathophys
A
alcoholic liver disease
- includes
- > steatosis
- > steatohepatitis
- > cirrhosis
- liver metabolism by ADH and ACDH
- > both reduce NAD to NADH
- > high NADH:NAD inhibits gluconeogenesis and increases
beta oxidation
- > accumulation of lipids
- CYP40
- > generates free radicals by NADPH to NADP
- > free radicals = inflammation, apoptosis and necrosis
- acetaldehyde creates antigenic adducts that drives inflamm
alcohol increases gut permeability to bacteria
- > taken up by portal vein
- > liver inflammation
11
Q
cirrhosis investigations
A
FBC -anaemia -thrombocytopenia EUC -hepatorenal LFTS -AST:ALT 2:1 in alcoholic -GGT induced by alcohol
Liver function:
Albumin
Coags
-PT
Causes:
- Hep
- > B surface antigen
- > C IgG
- autoimmune
- > ANA
- > anti-smooth muscle
- iron studies
- > haemochromotosis
- α 1 anti trypsin
Imaging
- upper endoscopy
- > varices
- ultrasound
- > small, nodular, hypertrophied caudate
- > splenomegaly, large portal vein
- CT/MRI following ultrasound
Biopsy
-usually unnecessary
Non invasive
- APRI
- > AST:platelet index
- transient elastography
12
Q
complications cirrhosis
A
portal HTN
- capillarisation/stellate contraction/nodules
- increased splanchnic blood flow due to vasodilation
- causes
- > splenomegaly
- > ascites
- > varices
splenomegaly
- due to portal HTN
- causes thrombotycopenia
ascites
- due to
- > portal HTN
- > splanchnic vasodilation from NO release
- > hypoalbuminaemia
- increases splanchnic lymph -> underfil of systemic arteries
- > activates RAS
- hyperaldosteronism
- > Na retention
- Na retention expands ECV
- > peripheral oedema
hepatorenal syndrome
- renal failure without renal pathology
- systemic hypotension with renal HTN
hepatic encephalopathy
- shunting of blood from liver
- > accumulation of toxins/metabolites
- FAM
- > false neurotransmitters
- > ammonia
- > mercaptam
other
- malnutrition
- > anorexia
- > poor gut absorption
- coagulation
- > factors, protein C/S, AT
- > thrombocytopenia
- > vitamin K
- osteoporosis
- > vitamin D absorption
death
-due to decompensation, above complications, variceal bleeding
13
Q
ddx dysphagia
A
solids only (constant)
- neoplasia
- > oesophageal
- > laryngeal
- strictures
- > GORD
- > radiation
- > caustic ingestion
- hiatus hernia
solids only (intermittent)
- eosinophilic oesophagitis
- rings
- webs
- vascular anomaly
liquids + solids
- neuromuscular
- > stroke
- > MS
- > myasthenia gravis
- motility disorder
- > achalasia
- > DES
- autoimmune
- > scleroderma
- > sjogrens
odynophagia +dysphagia
- pharyngitis
- > candida
- > strep
- pill induced
14
Q
upper GI ddx
A
UNACTED
- ulcer
- neoplasia/polyp
- angiodysplasia/AVM
- coagulopathy (medical/drugs)
- trauma (mallory weiss/buerharves)
- erosive esophagitis, gastritis, duodenitis
- deuilofoys lesion
15
Q
investigation upper GI bleed
A
ECG
FBC -anaemia (normocytic) Iron studies -suggests chronicity EUCs -urea:creatinine >100 LFTs -gastropathy/varices -coagulopathy Coags
Upper endoscopy with biopsy
- rapid urease test (with pH reagent –> colour change)
- histology with giemsia staining
- culture and sensitivity
Urea breath test -radiolabeled carbon isotope -split by urease -radiolabeled carbon dioxide breathed out Stool antigen
Consider
-fastig gastrin (zollinger ellison)
16
Q
ddx cirrhosis
A
All Viruses Are Nasty Bugs Causing Infections
- Alcohol
- Viral (B,C)
- Autoimmune
- NASH
- Biliary (primary sclerosing/biliary cholangitis)
- Cardiac
- Inherited (alpha 1 anti-trypsin deficiency, hereditary haemochromatosis, wilsons)
