GI Flashcards
what is AST a marker of?
hepatocellular damage
what can AST:ALT ratio tell you?
if AST >ALT = think more cirrhosis or acute alcoholic hepatitis
If ALT>AST = think more chronic liver disease
what is ALT a marker of?
hepatocellular damage
ALT increase of 3 fold suggestive of….
..cholestasis
ALT increase of 10 fold suggestive of…
…Hepatocellular injury
which LFT marker is most sensitive and which is most specific fro liver injury?
AST more sensitive
ALT more specific
What is ALP a marker of?
Cholestasis - comparison with ALT usually helpful in distinguishing
What does an isolated rise in ALP suggest?
bony mets/primary bone tumors
vit D def
*ALP rise not associated with GGT rise - hepatobiliary pathology
What is GGT a marker of?
marker of liver damage/disease
- more specific to liver than ALP
GGT indications?
screen for liver disease (bile duct problems)
- if associated with ALP rise - bile duct/liver disease
screen for alcohol abuse
What is albumin a marker of?
marker of synthetic function of the liver
What can cause a drop in albumin?
liver disease, inflammation in the liver and excessive loss (enteropathy or nephrotic syndrome)
What are other markers of synthetic function
INR/PT
Bilirubin - both reflection of liver function and damage - if levels are high - suggestive of obstruction
Bilirubin Indication?
measures jaundice - can also indicate cholestasis or liver (failure to conjugate bili)
what is serum lipase/amylase used for?
to test for acute pancreatitis
- often 3x ULN
what is calprotectin?
marker for IBD - higher in UC not very specific in cases of Crohn’s
Coeliac disease Ix?
Gold standard = OGD with duodenal biopsies
coeliac serology - TTG
total IgA & IgA TTG
what is faecal elastase?
measure of pancreatic insufficiency
low faecal elastase - suggestive of pancreatic insufficiency
patient usually presents with steatorrhoea - needs pancreatic enzyme supplementation
What are the main ways to test for H.Pylori?
- C13 urea breath test
- 6hrs fasting and 2wks ceasation of PPI use - Stool antigen - most common test
- off PPI for 2/52 - H,pylori serology - IgG Ab - only slowly falls after eradication
- Invasive testing for H.Pylori
- OGD and biopsy
- OCG & CLOtest - colour change from yellow to red
What is the QFIT test used for?
Quantitative Faecal Immunochemical test (qFIT)
- used to detect occult blood in faeces as part of colorectal screening programme
= every 2yrs ages 60-74
What should be done if FIT test results are abnormal?
Colonoscopy
Stool sample test indicated when?
What is tested for?
changes in bowel habit - typically diarrhoea
Campylobacter, Salmonella, Shigella and E.coli
Rotavirus
C.Diff
Ova/Parasites (3 samples <10day period)
what Ix is preferred when investigating threadworms?
perianal swab
Barium studies types and indications?
Oesophageal/oropharyngeal dyphagia = barium swallow
Barium enema - not common
- done before CT colon/colonoscopy
indications for Upper GI endoscopy/OGD?
Pts with refractory symptoms of reflux disease
indications of sigmoidoscopy?
- rectal bleeding
- diarrhoea in a young patient
- IBS
- left sided coilits
- bowelscope (aged 55)
Colonoscopy indication?
What’s involved?
Indications include - altered bowel habit, IBD, Bowel cancer screen, poly surveillance, pathology further investigated from sigmoidoscope
full bowel prep - laxatives the day prior to procedure
What is ERCP
type of endoscopy which observes the bile and pancreatice duct - can be used for both diagnostic and therapeutic purposes
- mainly used to check for blockages/stones
more therapeutic procedure - removal of obstructing stones
What is laparoscopy and its indications?
Laparoscopy is an operation performed in the abdomen or pelvis using small incisions with the aid of a camera. It aid diagnosis and mx of certain problems
Investigative purposes = endometriosis
Therapeutic purposes = appendecitis, splenectomy, renal tumours
What is Laparotomy and its uses?
more invasive compared to laparoscopy , involved a larger incision into the abdomen.
What is seHCAT and it’s uses?
A SeHCAT Scan is a diagnostic procedure to determine how well your gut is able to absorb bile acids. Poor absorption of the bile acid can result in chronic diarrhoea - chronic diarrhoea is the main indication
usually a 3hr and 7 days oral administration of Gamma-emitting synthesis bile acid - tauroselcholic [75 selenium] acid
10-15% retention value - mild malabsorption
5-10% - moderate malabsorption
0-5% - severe malabsorption
What is manometry and its uses?
catheter inserted into the oesophagus detector picks up the lower oesophageal sphincter pressure as you swallow water
uses = diagnosis of achalasia and oesophageal motility disorders
Indication of a liver biopsy?
useful when liver screen NAD and imaging uncertain
Indicated in autoimmune hepatitis and haemachromatosis (Perl’s stain)
used to
- diagnostic clues
- identify dominant pathology
- severity of disease processes = inflammation/fibrosis
Ambulatory pH-impedence monitoring
NG tube inserted via nasal passageway into oesophagus - measure acidic levels for 24hrs
Pts with refractory symptoms
non-responsive to PPI use
cannot tolerate PPI
Investigations for bowel obstruction?
Gold standard - CT
MRI can also be used in IBD to look for obstruction
Abdo US indications?
Pros and cons?
first line for abnormal LFTS
pros - quick, cheap, no radiation/safe, doppler allows assessment of blood flow
CT abdomen Pros and cons?
pros - cross-sectionla imaging, good anatomical detail, quick, visualises pancrease
Cons - radiation exposure
MRI Pros and cons?
pros - great resolution, no radiation, good for biliary pathology and liver lesions
Cons - costly, claustrophobia and lengthy, avoided with metallic implants
what is used to stratify upper GI bleeds
Blatchford Score
- Hb, HR, sysBP, gender, melena, recent syncope, heaptic disease hx and nlood urea nitrogen
> 1 = need endoscopy in hopsital
Investigations in diarrhoea
- FBC, iron studies - blood loss or infection
- B12/folater - anaemia
- U+Es, ESR/CRP, TFTd and coeliac screen
- stool test - MCS & OVP
- faecal elastase and calprotectin
- sigmoid/colonoscopy
- uread breath test
2WWR Clinic Ix Include…
OGD/colonoscopy
Blood tests
CT /MRI
Investigations in suspected Biliary Colic?
Abdo US
Investigations in suspected Acute Cholecystitis?
Abdo US
- if unclear HIDA scan
Bloods - LFTs usually normal (ALP rise compared to ALT), CRP, WCC & amylase
Investigations in suspected Ascending Cholangitis?
Abdo US - presence of stone & bile duct dilatation
Bloods - raised ALT/ALP/Bilirubin
Investigations in suspected Primary Sclerosing Cholangitis?
Diagnostic - ERCP/MRCP = beaded strictures of biliary ducts
LFTs = ALP and bili, pANCA +ve
Biopsy = fibrosis, onion skin appearance
Investigations in suspected acute pancreatitis?
Serum amylase/lipase
potential raised ALP
Imaging - early US or contrast-enhanced CT
MRCP done if underlying cause unclear
Investigations in suspected chronic pancreatitis?
Abdo XR - pancreatic calcifications
CT abdo - more sensitive
Faecal elastase - asses exocrine function
Investigations in suspected Pancreatic cancer?
CT abdo preferred - US can be done but less sensitive
bloods - ALP raised, CA19-9, lipase and amylase raised
LFTS = cholestatic LFTs picture
Interpretation of hepatitis B serology?
HBsAg ⇒ seen in active infection
HBsAb ⇒ seen in current or past infections or as a result of vaccination
HBcAB ⇒ current or past infection
→ IgM = active infection
→ IgG = past infection
HBeAg ⇒ virus actively replicating, acute phase of infection
→ the higher this marker is, the more infectious the person is
Investigations in suspected Hepatitis?
LFTs - derranged ⇒ high levels of AST/ALT and proportional rise in ALP = ‘hepatic picture’
Hep B serology or Hep C testing
Investigations in suspected Autoimmune Hepatitis?
Diagnosis is given from liver biopsy results
Investigations in suspected Cirrhosis?
LFTs = reduced synthetic function - low albumin and increased PT
abdo US = nodular surface, ascites, splenomegaly, enlarged portal vein
Transient Elastography/Fibroscan = offer to pts if above 55yrs, hx of alcoholic fatty liver disease, etoh >50U/week and HepC infection
aFP checked as cirrhosis increases risk of hepatocellular carcinomas
Investigations in suspected hepatocellular carcinoma?
aFP and abdo US
Investigations in suspected Non-alcoholic Fatty liver disease?
usually asymptomatic - incidental finding on US
enhanced liver cirrhosis ELF test - allows detection of any advanced cirrhosis
Investigations in suspected Peritonitis?
paracentesis - MSC, >250 neutrophils
MSC usually cultures E.Coli
Investigations in suspected GI (peptic ucler) perforation?
Erect CXR = pseudo diaphragm
Investigations for suspected Peptic Ulcer Disease?
Reintroduce gluten into diet 6wks prior to Ix
- TTG Ab serology = first choice Ix
- others include = IgA, anti-gliadin/caesin Ab - GOLD ST = endoscopic intestinal biopsy
- vilious atrophy
- crypt hyperplasia
- intraepithelial lymphocytes
Investigations for suspected C.difficile Infection?
- Stool MCS
- Bloods - WCC
- if normal = mild CD
- if raised with loose stools = moderate
- if raised with creatinine elevation, fever or evidence of coilitis = severe
Check U&E - creatinine
Investigations for suspected Gastroenteritis?
stool MCS
Investigations for suspected Crohn’s Disease?
routine bloods = FBC, U&Es, LFTs, Ferritin, B12&Folate
endoscopy - Colonoscopy preferred = deep ulceration, skip lesions
Biopsy & Histology - all layers inflamed, goblet cells and granulomas
R/O other pathology = Coeliac serology, CRP/ESR, TFTs, U&Es, Ferritin, VitB12&D and folate
Investigations for suspected Ulcerative coilitis?
Bloods = FBC, CRP/ESR, TFTs, U&Es, ferritin, VitB12&D and folate
Stool MCS & calprotectin (usually very high)
Coeliac serology
Barium Enema
- loss of haustrations
- short narrow colon - ‘drainpipe colon’
- superficial ulcerations and pseudopolyps
Investigations for suspected Constipation & faceal impaction?
usually clinical AXR - faceal impaction
Investigations for suspected Irritable Bowel Syndrome?
Bloods = FBC, ESR/CRP, coeliac serology - TTG Ab
IBS is a diagnosis of exclusion
- investigation results are usually non-specific
Investigations for suspected Diverticulitis?
usually diagnosis is given in secondary care - under specialist or colorectal surgery
CT colonography
Colonoscopy - if perforation is suspected
Barium Enema
blood test - FBC, U&ES, CRP
FIT test - if any PR bleeding
Investigations for suspected Appendicitis?
Abdo US first line
Raised inflammatory markers - CRP/ESR
MAKE SURE TO RULE OUT
- UTI
- Pregnancy (if female)
Investigations for suspected Intussusception?
US abdo will show ‘target like mass’
contrast enema
Investigations for suspected Acute Mesenteric Ischaemia?
DIAGNOSTIC - Contrast CT
VBG - metabolic acidosis due to increased lactate
Investigations for suspected Chronic Mesenteric Ischaemia?
CT angiography is diagnostic imaging
Investigations for suspected Bowel Obstruction?
AXR - intraretroperitoneal space suggestive of colonic perforation
CT = GOLD ST, highly specific
Bloods = U&Es - may have electrolyte imbalance
VBG = metabolic acidosis - increased lactate from ischaemia
Investigations for suspected Toxic Megacolon?
AXR = massively dilated colon CTTAP = normal haustra absent, thickened walls, colonic dilatation
Bloods = FBC, U&Es, Albumin, lactate and CRP/ESR
Bloods culture
stool MCS
Investigations for suspected Oesophagitis?
Endoscopy = inflammed oesophagus
pH testing
Investigations for suspected Barretts Oesophagus?
endoscopic biopsy = change from columnar to squamous epithelium
Investigations for suspected Mallory Weiss Tears?
endoscopy
Bloods - FBC, Coag studies, Platelet count, Routine U&Es, group+save, crossmatch
Investigations for suspected oesophageal stricture?
preferred - barium swallow = clarifies nature, length of stricture
Endoscopy - often a biopsy can be taken
CXR = ?impingment from a mass
Bloods - FBC, Ferritin and LFTs
Investigations for suspected Oesophageal Neoplasm?
first line = upper GI endoscopy
If metastatic - CTAP for staging
if not metastatic - US endoscopy
Barium swallow helpful in ruling out motility disorders
Investigations for suspected Oesophageal Varices?
Bloods = Hb, U&Es, urea, coag profile, LFTs & crossmatch
Endoscopy - ROCKALL SCORING DONE PRIOR
Investigations for suspected Achalasia?
Diagnostic/Gold ST = oesophageal manometry
- pressure in cardiac sphincter
- incomplete relaxation on swallowing
- absent peristalasis
Barium Swallow
- ‘birds beak appearance’
- grossly expanded oesophagus
CXR = widened mediastinum
Indications to investigate GORD?
Ix indications
- 55yrs or older
- persistent symptoms - not responsive to tx
- dysphagia
- assciated weight loss
Investigations for suspected GORD
Endoscopy = assess for peptic ulcers, malignancies
H,pylori testing
CLO test
GOLD ST = if endoscopy neg = 24hr oesophageal pH monitoring
Investigations for suspected Gastritis?
Clinical diagnosis
Investigations for suspected peptic Ulcer disease?
Diagnostic = endoscopy
Biopsy done to rule out any malignancy
often CLO test done simultaneously
Investigations for suspected Pyloric Stenosis
Abdo US
Bloods may show hyperchloremic, hypokalaemic alkalosis
Investigations for suspected Oesophageal Neoplasms?
Diagnostic = endoscopy + biopsy
staging
- endoscopic US
- CT
Investigations for suspected Hernias?
US - incisional, inguinal, ventral, umbilical
Hiatus - endoscopy, barium swallow and CXR
Investigations for suspected Haemorrhoids?
Protoscopy
- able to confirm diagnsis, assess severity
If hx of significant/Chronic PR bleeding - do an FBC
Investigations for suspected suspected Anal Fissure?
clinical diagnosis on DRE exam
FBC if significan/chronic bleeding
Investigations for suspected Anorectal abscess/fistula?
clinical diagnosis on DRE exam
- erythmeatous, painful swelling - surrounding cellulitis
- usually DRE to painful to perform
Investigations for suspected Pilonodal disease?
clinical diagnosis
Ix to r/o - crohn’s infectious processes such as TB, Syphillis
Investigations for suspected Polyps?
colonoscopy
CT colonography
Investigations for suspected Rectal Neoplasms?
colonoscopy & biopsy suspicious lesions (GOLD ST)
- sigmoidoscopy
CT colonography - unsuitable for colonoscopy or staging confirmed colorectal cancer
FBC and CEA
Screening for colorectal cancer involves?
FIT test
60-74yrs = every 2 yrs
> 50yrs with unexplained weight loss
<60yrs with change in bowel habit
RF patient - offered colonoscopy at regular intervals
- Familial Polyadenosis
- HNPCC
- IBD
