GI and LFTs Flashcards
what is inculded in LFTs
AST(SGOT), ALT(SGPT)
Alkaline Phosphatase
Total Bilirubin
Albumin
Total Protein/Globulins
clinical application and shortcomings of LFTs
•Despite being called “Liver function tests”, they do not actually provide any information about the liver’s function
•Clinical Application:
- Non-invasive screen for possible liver disease
- Can be used to measure treatment efficacy in certain liver diseases
- Monitor progression of disease such as viral or alcoholic hepatitis
- Reflect severity of liver disease in patients who have cirrhosis, and be used to reflect prognosis (Usually in conjunction with albumin, PT/INR)
•Shortcomings:
- Abnormal values could also be from a non-hepatic source
- Labs can be normal in advanced liver disease and hepatic cancer
what are the 3 patterns of LFT abnormalities & how are they defined?
•1. Hepatocellular pattern: Disproportionate elevation in the transaminases (AST/ALT) compared with the alkaline phosphatase
•Serum bilirubin may be elevated
•2. Cholestatic pattern: Disproportionate elevation in the alkaline phosphatase compared with the transaminases (AST/ALT)
•Bilirubin may be elevated
•3. Isolated hyperbilirubinemia: Elevate bilirubin with normal transaminases and alkaline phosphatase
•Synthetic liver tests can be normal or abnormal in any of these
Diff Dx for hepatoceullar pattern
Acet Tox
DILI
Viral Hep A, B, C
ETOH hep
autoimmune Hep
NAFLD
Diff dx for cholestatic pattern
conditions where flow of bile from liver is reduced or blocked
choledocholithiasis
biliary obstruction
enzymes that reflect hepatocell vs cholestatic pattern
hepatocell - AST, ALT
chole - Alk phos, GGT, 5-nucleotidase
Tests that measure biosynthetic function of the liver
Albumin
globulins
coagulation (PT/INR)
define bilirubin and its 2 components
- a breakdown of the porphyrin ring of of heme-containing proteins
- Unconjugated – (indirect bili) fraction is insoluble in water and is bound to albumin in the blood
- Calculated as total-direct
- Conjugated – or direct bilirubin is water-soluble and can be excreted by the kidney
Lactate dehydrogenase is a marker for ______.
hemolysis
elevation in indirect bili could indicate
Elevation is rarely due to liver dz -> Requires hemolytic work-up
Isolated elevation is likely due to hemolytic disorders/ genetic conditions
elevation in direct bili could indiczte
Elevation almost ALWAYS implies liver or biliary tract dz -> seen in MANY types of liver dz
•Choledocholithiasis
define the transaminases
AST
•Found in liver, cardiac muscle, skeletal muscle, kidneys, brain, pancreas, lungs leukocytes and erythrocytes in decreasing order of concentration
ALT
•Found primarily in the liver -> more specific indicator of liver injury
define alk phos
•Found in or near bile canicular membrane of hepatocytes
Consists of many isoenzymes found in the liver, bone, placenta and less commonly in the small intestines
- Enzyme present in cells that join to form bile ducts
- Also found in bone, as well as other tissues – can be fractionated
- If elevated & it is the only elevated finding try and figure out source of excess isoenzymes -> measure GGT & 5-nuceotidase as they are rarely elevated in conditions other then liver disease
Transaminase ratio in
Viral hepatitis & NAFLD
VS
Alcoholic liver dz
HEP - AST:ALT <1 - ALT MORE elevated than AST
ETOH - AST:ALT >2:1 - AST MORE elevated
Tests that measure biosynthetic function of the liver
Serum Albumin
Serum Globulins
PT/INR
define albumin and when it can be normal or LOW
- Synthesized exclusively by hepatocytes -> long half-lives with a slow turnover
- Not great markers of liver injury due to to their long half-life and slow turnover times -> LATE finding
- NORMAL -> hepatitis, drug-related hepatoxicity and obstructive jaundice
- Changes are seen in acute liver conditions -> _abnormally low in chronic liver d_z
PT/INR in the setting of abnormal LFTs will help determine
if liver is working!
if it is normal then just hepatic inflammation
Choledocholithiasis shows what si/sx & lab values
RUQ pain*** radiates to back
jaundice, dark urine
(+) Murphy’s sign
↑direct bili ****
↑ AST/ALT
↑alk phos (slow)
7 and 11 rule in CBD
Normal CBD:
- <7mm w/ GB present
- <11mm – w/o GB (s/p cholecystectomy)
Imaging and Tx of Choledocholithiasis
RUQ US & CT show dilated ducts,
MRCP – Best non-invasive test*
ERCP – need to weigh the benefit/risks
Endoscopic ultrasound
Intra-operative cholangiogram at the time of CCY
TX:
ECRP to remove stone
THEN contact surgery to remove gallbladder (Cholecystectomy)
pt appears to ER w/
Nausea/vomiting
Abdominal pain
LABS: AST:ALT ratio of 2:1
Dx?? & Tx???
Acute ETOH Hepatitis
ETOH Withdrawal treatment/ CIWA protocol-> Phenobarbital & Lorazepam
IV fluids-> Include MV, thiamine and folate – Wernicke’s Encephalopathy coverage
Calculate Maddrey’s Discriminant Function
AST to ALT ratio is less then 1
RUQ US – increased echogenicity consistent with hepatic steatosis
DX??
NAFLD
Si/sx & tx of NAFLD
Jaundice
↑transaminases
Usually obese, HTN, T2D
Abstain from alcohol
Optimize glucose control, HTN management and cholesterol therapy
Weight loss of 1-2lbs per week , Nutritionist referral
Check LFT’s after 3 and 6 months to monitor for improvement
If no improvement, consider: Bariatric surgery
RUQ US – increased echogenicity consistent with hepatic steatosis
dx?
NAFLD
RUQ US & CT show dilated ducts,
Dx?
Choledocholithiasis
RUQ US: hepatomegaly
dx?
Hepatitis
Labs in Hep C
AST/ALT - normal - elevated
Tbili - mildly elevated
Alk Phos - normal
alk phos in NAFLD is ____
normal
elevated indirect bili in the setting of normal LFT
dx?
Gilbert Syndrome
Tx of Hep C
w/o cirrhosis
w cirrhosis
w/o cirrhosis
- Glecaprevir/pibrentasvir
- Sofosbuvir / velpatasvir
w/ cirrhosis
•Genotype 1-6: Glecaprevir / pibrentasvir
• Genotype 1, 2, 4, 5, or 6 Sofosbuvir/ velpatasvir
Upper GI vs Lower GI Bleeds are defined as:
Upper: Defines as bleeding derived from a source PROXIMAL to the Ligament of Treitz
Si/Sx of Upper GI Bleeds
Hematemesis “coffee-ground”
Melena – black tarry stool heme (+)
Hematochezia – dark red blood in stool
Hemodynamic instability(Hypotensive, tachycardia, orthostatic)
Hgb <10
Factors influencing outcome of upper GI Bleeds
CV compromise
Age >65
Co-existing cardio-respiratory dz
HgB <10
Hematemesis & melena
tx of upper GI Bleeds
Stabilize ABCs
Fluid resuscitation
Type and screen – transfuse 2 units
FFP
PLTs <50k and actively bleeding
Start on PPI – protonix (pantroprozole)
- omeprazole, esomeprazole, lansoprazole, pantoprazole
- PPIs are recommended for ALL patients with peptic ulcer bleeding
No H2-blockers due to tachyphylaxis
ONCE stable transfer for urgent endoscopy