JR Clinical biochemistry Flashcards
What is a pink sample tube for?
EDTA - Haematology (cytology) - cells in fluid sample
What is a red sample tube for?
Plain serum biochemistry - no anticoagulant
What is an orange sample tube for?
Biochemistry with heparin - anticoagulant
What is a yellow tube for?
Oxalate fluoride
What is oxalate fluoride sample tube for?
Glucose analysis
What is a green sample tube for?
PT/aPTT - shows blood clotting times
What is a serum tube required for?
Bile acids
Haptoglobin
Serum protein electrophoresis
How does stress affect biochemistry samples?
Increased glucose in cats
Increased WBCs
Splenic contraction - increased PCV, HCT
What three things cause interference with spectrophotometric assays?
Haemolysis - red
Lipaema - turbidity/less clear
Icterus - yellow
What does spectrophotometry do (graph at bottom of blood results)?
Measures how much of an analyte there is in a sample
What two things make up total protein?
Albumin and globulin
What is used to estimate total protein?
Refractometer - measures total solids
Where is albumin synthesised?
Liver
What is albumins primary job?
Maintaining colloid oncotic pressure
What is commonly bound to albumin?
Calcium
What does acute phase proteins mean?
Proteins thats levels are affected by inflammation - some increase and some decrease
What type of acute phase protein is albumin?
Negative acute phase protein
What can cause hypoalbuminaemia?
Reduced production - liver dysfunction
GI disease - protein losing enteropathy
Kidney disease - protein losing nephropathy
What is panhypoproteinaemia?
When both albumin and globulin are low
What can cause panhypoproteinaemia?
Haemorrhage
Exudative disease eg. burns
What are globulins synthesised by?
Plasma B cells
What can cause hypoglobulinaemia?
Immune incompetence
Protein loss from haemorrhage etc.
What is more common - hypo or hyperglobulinaemia?
Hyperglobulinaemia
What is used to analyse hyperglobulinaemia?
Serum protein electrophoresis
What does a broad peak on serum protein electrophoresis mean?
Inflammatory response
What does a massive increase in gamma globulin normally mean on serum protein electrophoresis?
Neoplastic proliferation of plasma cells
What is a positive acute phase protein in dogs?
C reactive protein
What is a positive acute phase protein in cats?
AGP
What is a positive acute phase protein in horses?
Serum amyloid A
What can cause hypoglycaemia?
Severe sepsis
Hepatic dysfunction - cant synthesise
Excess insulin - insulinoma neoplasma
Addisons (hypoadrenocorticism)
Iatrogenic
How do you tell the difference between transient and persistent hyperglycaemia?
Urine glucose
Frucosamine - glucose bound to albumin
What is the most common ketone?
Beta-hydroxybutyric acid (BHB)
How are ketones measured?
Dipstix - but not BHB
What ketones do dipstix measure?
Acetone and acetoacetate, not BHB
What are markers of lipolysis?
Non-esterified fatty acids
What can cause hyperlipidaemia?
Diet - obesity
Increased production/metabolism eg. diabetes increasing fat breakdown
Cholestasis
What are the main types of triglycerides?
Enterocytes - diet
Adipocytes - fat
Hepatocytes
What are some specific signs of liver disease?
Icterus
Coagulopathy
Ascites - fluid accumulation
Hepatic encephalopathy
What are the hepatocellular enzymes that indicate liver damage in dogs and cats?
Alanine aminotransferase (ALT) Aspartate aminotransferase (AST)
Where is ALT found?
Liver cytoplasm only
Where is AST found?
Mitochondrial - liver and muscles
What are the hepatocellular enzymes that indicate liver damage in large animals?
Sorbitol dehydrogenase (SDH) Glutamate dehydrogenase (GLDH)
What are the two different reasons for elevated hepatocellular enzymes?
Primary liver disease
Secondary/reactive liver disease - inflammation elsewhere in body
What is cholestasis?
Impaired bile flow
What are the two cholestatic enzymes?
Alkaline phosphatase (ALP) Gamma glutamyl transferase (GGT)
Which cholestatic enzyme is more sensitive in large animals?
Gamma glutamyl transferase (GGT)
What can affect cholestatic enzyme levels?
Cholestatic isoenzymes
What can cause cholestatic enzyme elevations?
Disease of biliary tree
Endocrine diseases causing liver swelling
Steroids
What are isoenzymes?
Enzymes that catalyse the same reaction but come from a different origin
What produces bilirubin?
RBC breakdown
What causes prehepatic jaundice?
Haemolysis
What causes hepatic jaundice?
Liver damage, cant conjugate bilirubin
What causes post-hepatic jaundice?
Cholestasis
What is the main cause of jaundice in cattle?
Haemolysis
eg.babesia
How can you tell if it is prehepatic jaundice?
If there is a low PCV due to regenerative anaemia
How can you tell if it is hepatic jaundice?
Elevated hepatocellular enzymes
How can you tell if it is post hepatic jaunice?
Elevated cholestatic enzymes
What are bile acid/salts function?
Fat digestion/absorption
What is used to make bile acids?
Cholesterol
What amino acid is used to conjugate cholesterol into bile acids?
Taurine
What does the bile acid tolerance test evaluate?
Bile acid levels in blood samples taken before and after a meal
What are elevated bile acid levels a marker of?
Cholestasis
Hepatic dysfunction
Portosystemic shunt
What is a marker of muscle damage?
Creatine kinase
What test do you do for pancreatitis?
Pancreatic lipase immunoreactivity
What does a negative SNAP PLI test mean?
Definitely doesnt have pancreatitis
What does a positive SNAP PLI test mean?
Might have pancreatitis, do spec test to confirm
What are B vitamins used to evaluate?
GI tract function
Where is folate (vitamin B9) absorbed?
Proximal SI - jejunum
Where is cobalamin (vitamin B12) absorbed?
Distal SI - ilium
What do you need to absorb cobalamin/vitamin B12?
Intrinsic factor from the pancreas - exocrine pancreatic insufficiency
What are some indicators of kidney injury?
PUPD
Metabolic acidosis - lose acid/base regulation
Uraemia/azotemia
Proteinuria
What is azotemia?
Increased urea and/or increased creatinine in the blood
What is uraemia?
Clinical syndrome arising from azotemia
What causes pre renal azotemia?
Reduced renal perfusion - not enough blood pressure to filter in glomerulus
What is a sign that it is pre-renal azotemia?
Azotemia with concentrated urine
What causes renal azotemia?
Fewer functioning nephrons
What is a sign that it is renal azotemia?
Azotemia with dilute urine (not enough nephrons to concentrate it)
How many nephrons do the kidneys need to lose to become azotemic?
75% - high functional reserve capacity
What causes a post-renal azotemia?
Obstruction or rupture of urinary tract
How do you measure glomerular filtration rate in animals?
Urea levels - but can be influenced by diet
Creatine levels
What happens to phosphates and potassium with renal disease?
Hyperphosphataemia and hyperkalaemia - are primarily renally excreted so accumilate
What are some non sterile methods of urine collection?
Free catch
Non-absorbable cat litter
Catheterisation
What is the only sterile method of urine collection?
Cystocentesis - needle into bladder
What does glucosuria with hyperglycaemia mean?
Diabetes mellitus - high in both blood and urine
What does glucosuria with normal blood glucose levels mean?
Problem with proximal tubule
What does bilirubinuria suggest?
Normal in dogs
Abnormal in others
What does ketonuria mean?
Diabetes mellitus
How do you measure urine specific gravity?
Refractometer
What does hypersthenuria mean?
Concentrated urine - specific gravity
What does haemoglobinuria suggest?
Haemolysis
What does heamuria suggest?
Primary urinary tract disease - bleeding
What does proteinuria suggest?
Glomerular dysfunction
What is abnormal in crystalluria?
Urates
Casts of tubule
What is sodium responsible for in the body?
Preservation of electroneutrality - water retention/loss
What is hyponatremia?
Low sodium
What can cause hyponatremia?
Los of Na+ - vomiting, renal disease etc.
Gain of water - drink too much etc.
Endogenous shifts - diabetes etc.
What can cause hypernatremia?
Gain Na+ - salt from sea etc.
Loss of water - diabetes, GI losses, burns, not drinking enough
What does the body produce in response to chronic sodium disturbance?
Idiogenic osmoles - prevent changes to cell swelling in CNS
How do idiogenic osmoles affect treatment of sodium disturbances?
If acute - can treat quickly as havent had a chance to make them yet
If chronic - need to correct Na+ slowly
What is chlorines job in the body?
Preserves electroneutrality - follows sodium
What causes hyperchloraemic metabolic acidosis?
Loss of other anions so Cl is retained to compensate
What can cause hypo/hyperchloraemia?
Hypo/hypernatremia - follows sodium
What can cause hypochloraemia without hyponatraemia?
Gain of other anions
Lactic acidosis
Ketoacidosis
Azotemia
What can cause hyperchloraemia without hypernatremia?
Loss of other anions eg. bicarbonate
GI losses
Renal losses
What effect does hyperkalaemia have on the body?
Cardiac problems - bradycardia, heart attack
What effect does hypokalaemia have on the body?
Muscle weakness, lethargy
What regulates potassium excretion in the kidney?
Aldosterone
What does a low Na:K ratio (<20) indicate?
Addisons disease - hypoadrenocorticism
What function does calcium have in the body?
Muscle contraction
Nerve conduction
What electrolyte is linked to calcium?
Phosphates - same hormonal regulation
What hormone increases calcium and phosphate levels?
Parathyroid hormone
What hormone decreases calcium and phosphate levels?
Calcitonin
What can cause an increase in calcium and a decrease in phosphate?
Cancer - produces PTHrp
What can cause hypocalcaemia?
Lactation - milk fever
Sepsis
Pancreatitis
