Components of U&E
Urea
Na+
K+
Creatinine
What to request in stool
Microscopy
Culture
Sensitivity (to work out antibiotic)
What tests involved in LFT
Albulin, Bilirubin, alkaline phosphatase (different isoenzymes for bone and liver), ALT
Blood test
U&E : serum in yellow/red top Glucose: plasma in grey top HBA1c: plasma in purple top TFT: serum in yellow/red top Liver function tests: in yellow/red top
How to measure glucose in blood
Red cells consume glucose (anaerobic glycolysis), so the longer this is left out, the lower the glucose may read Fluoride Oxalate (poison) prevents the red cells from using glucose
High K+ and low Na+
shows adrenal failure perhaps
What would high urea with normal creatinine show
could show dehydrated…. urea doesn’t show much about kidney health… creatinine shows more shows more about GFR
What is postassium EDTA and what tubes have this
This is a strong anticoagulant and these tubes are usually used for complete blood count
PURPLE
What colour bottle for flouride oxalate
Grey top (=poison)
What do red and yellow top bottles contain
red- nothing
yellow top- have gel to speed up clot
What colour bottle for each of following: U&E Glucose HBA1c TFT LFT
U&E : serum in yellow/red top Glucose: plasma in grey top HBA1c: plasma in purple top TFT: serum in yellow/red top Liver function tests: in yellow/red top
Differentiate serum and plasma
Serum is that part of blood which is similar in composition with plasma but exclude clotting factors of blood.
How do you get serum from plasma
e.g. U&E….
Serum in red/yellow top…. blood will clot (as no anticoag.) then just remove clots, leaves serum behind
Give 2 examples of anticoagulants used in bloods
EDTA or heparin
What can samples which have added anticoagulant be separated into
Clotting factors unused so
Blood can be separated into red cells and plasma
Reference range for Na K U Cr
Na+: 135 – 145)
K: 3.5 – 5.0)
U: 2.0 – 6.0)
Cr: (NR 70 – 120)
High potassium what could be the cause
Could be adrenal failure
OR
could be haemolysed sample (i.e. RBCs split open in the sample)
What is creatinine a arker of
GFR
If dehydrated, both creat. and urea increase … t/f
f: Urea levels rise when a patient is dehydrated but GFR stays the same to the end.
What enzymes are looked at in LFT
Albumin: synthesised in the liver
Bilirubin
Alkaline Phosphatase
ALT (alanine amino-transferase)
What other enzyms would you measure in a patient with jaundice
AST and GGT
What are the cardiac enzymes
Troponins
Creatine kinase (CK)
Aspartate amino transferase (AST)
Lactate Dehydrogenase (LDH)
Talk about AST and ALP. in terms of specificity and when they are raised
AST not speciifc to liver…. when raised it indicated peri-portal damage (i.e. damage to cells around the portal triad)
ALP is more speciic to liver…..
They don’t indicated liver FUNCTION, they indicate DAMAGE level, as they are released due to hepatocellular damage due to inflammation
When might albulin be low
CHRONIC liver injury (as albulin as 20 day half life so takes a while for it to fall)