Biochemistry and Urinalysis Flashcards
Give examples of clinical pathology tests…
Haematology Clotting profile Biochemistry Urinalysis Cytology
What is biochemistry used for?
Evaluating different organ systems
Measuring enzymes, metabolites, electrolytes
Why is serum recommended for most biochemical tests rather than plasma?
Anticoagulants in plasma can interfere with some tests
What is the difference between serum and plasma?
Plasma contains all clotting factors including fibrogen, where as serum is fluid after clot formation
How would you collect serum?
Collect blood intro tubes without anti-coagulatants (brown/red top)
How would you separate serum?
Allow blood to clot and remove serum Centrifuge Serum separator tube Separate immediately if possible Store in fridge at 4deg
How would you collect plasma?
Collect from blood into EDTA, heparin or citrate
Blood won’t clot so need to separate plasma via centrifugation
Store at 4 deg
What is measured in a biochemical profile?
Total protein Albumin Globulins Bicarbonate Anion gap Calcium Phosphorus Glucose Electrolytes Urea nitrogen Creatinine Bilirubin Cholesterol Amylase Lipase CK ALT ALP SDH GLDH
Why are total protein levels often higher in plasma?
Fibrinogen is included
What is total protein made up of?
Albumin
Globulins
How is total protein measured?
Using a refractometer
What conditions may falsely increase total proteins?
Icterus
Severe haemolysis
Lipemia (blocks light so can appear darker blue)
How can you stop dietary lipemia increasing TP measurements?
Starve animal before test
What increases TP?
Dehydration
Inflammation
Neoplasia
What decreases TP?
Loss
Decreased synthesis
Dilution
Why do globulin need to be separated by electrophoresis?
There are different types
What can cause an increase in globulins?
Inflammation (polyclonal)
Neoplasia (monoclonal)
How can you calculate globulin levels?
Take TP, removed AL and whats left is globulins
What is polyclonal gammopathy?
Increase in all types of globulins e.g. FIP
What is monoclonal gammopathy?
Increase in a single type of Ig by a single clone of cells e.g. plasma cell tumour
What causes an increase in albumin?
Dehydration
What causes a decrease in albumin?
Increased loss (renal, GI, haemorrhage) Decreased synth (liver) Third spacing (effusions)
What does it mean if you are dehydrated and have normal albumin levels?
You had low albumin to start with
How would you evaluate liver function?
Enzymes
Metabolites
Function tests
What does an increase in liver enzymes mean?
Leak from damaged cells so indicates liver disease
How would you evaluate pancreas function?
Amylase and lipase
What could an increase in pancreatic enzymes be indicative of?
Leak from damaged cells (pancreatitis)
Renal insufficiency
What do you need to look at to evaluate the urinary system?
Serum chemistry
Urine
What are good indicators of GFR?
Urea
Creatinine
What is low urea indicative of’?
Liver damage
What is high urea indicative of?
Kidney damage
What is creatinine derived from and what does an increase menan?
Creatine in muscle (influenced by mm)
Increase - kidneys not excreting it properly
What is azotemia?
Increase in nitrogenous waste in circulation
What can cause azotemia?
Pre-renal (dehydration)
Renal (renal disease)
Post-renal (obstruction)
Describe pre-renal azotemia…
Decreased blood volume + therefore pressure
Body responds by increasing HR and constricting vessels
Reduces kidney filtration and urea excretion
What would you check to analyse the cause of azotemia?
USG
Blood and urine analysis
If urea and creatinine are increased what should the urine specific gravity be in…
a. Dog
b. Cat
c. Horse/ruminant
What does it mean if the values are less?
a. 1.030
b. 1.035
c. 1.025
Decreased concentrating ability and renal failure is present
What species is urea not a reliable indicator of renal disease in? Why? What should be used instead?
Ruminants
Urea levels influenced by protein intake , high protein meal, GI bleeding
Creatinine
Why may you get increased sodium levels?
Increased intake
Increased water loss
Decrease water intake
Why might you get decreased sodium levels?
Increased loss
Increased water intake
What is the main ion in ECF?
Sodium
What is the main ion in intracellular space?
Potassium
What is an increase in potassium associated with?
Renal failure
HypoAC
Leakage from cells (tissue damage, thombocytosis, leukemia)
What is a decrease in potassium associated with?
Loss (renal, vomiting, diarrhoea)
Decreased intake
What do changes in chloride usually coincide with?
Changes in sodium
What are changes in chloride without sodium associated with?
Alterations in acid-base balance
Vomiting
Abomasal displacement
When you measure total calcium what are you measuring?
Free calcium
Bound calcium
What is an increase in phosphorus associated with?
Renal disease
Young growing animals with also evaluated Ca and ALP
What do you analyse with urinalysis?
Gross appearance Chemical analysis (SG, dipstick) Sediment analysis (cellular elements, crystals, casts)
