Maintenance and blood sampling

What does the centrifuge do

• Spins a substance to separate the fluid portion from the solid content

• Speeds up the natural process of gravity

What is the fluid portion alternatively known as

Supernatant

What is the solid content alternatively known as

Sediment

What can the centrifuge spin down

• PCV

• TP

• Urine sediment

• Blood

• Faeces

Centrifuge safety rules

• Do not open while still running

• Don’t forget the plate

• Must be balanced properly

How fast is blood spun and how long for

• 10,000 rpm

• 5 minutes

How fast is urine spun and how long for

• 1000-2000 rpm

• 3-5 minutes

How fast is serum spun and how long for

• 2.500-3,000 rpm

• 10-15 minutes

• Must clot for 15-20 minutes before spinning

Centrifuge more info

• Clean regularly

• Check for broken glass

• Replace the rubber ring (depending on use will depend on how often)

• Flat strong surface required (ideally away from microscope)

Use of heparin tube

Taking blood directly from the patient

Use of plain tubes

Taking blood from a tube/sample

What is a Hawksley reader used for

To read a PCV

Normal PCV range for a cat

24%-35%

Normal PCV range for a dog

• 35%-45%

• Sighthound- 45%-55%

What causes a high PCV

• Dehydration (less serum = more RBCs and higher PCV)

• Polycythaemia- produced more RBCs than normal (usually hypoxic patients)

• Acute bleed- spleen contracts, PCV isn’t actually higher it will just read higher at first

What causes a low PCV

Anaemia

What does a refractometer measure

• Specific gravity (SG) of urine

• Total protein (g/L OR g/DL) of serum

What is the SG of diluted water

1.000

What is the prism

Glass screen of refractometer

How to calibrate a refractometer

• Apply 2 drops of distilled water to prism

• Adjust using a screwdriver if necessary

• Ensure SG of distilled water is 1.000

Normal TP of cats

66-84 g/L

Normal TP of a dog

55-72 g/L

What does hyperprteinaemia mean

High protein

What does hypoproteinaemia mean

low protein

Why are blood samples taken

• To determine if infection/inflammation is present

• Organ function (liver/kidney)

• Blood glucose

• Hypotension

• Clotting-platelet count and coag tests

• Electrolytes

• Blood typing

What happens when samples are put in a fridge

Cell activity reduces

What happens when a sample becomes ‘old’

• Platelets break down (looks like there are none)

• Cells will use up the glucose (will look like none, hypoglycaemic)

• If blood smear is done the cells will appear shrivelled

Blood sites in cats

• Jugular

• Cephalic

• Medial saphenous

Blood sites in dogs

• Jugular

• Cephalic

• Lateral saphenous

Blood sites in Rabbit

• Jugular

• Marginal ear vein

• Cephalic

Blood sites in exotics

• Ventral tail

• Jugular

Blood sites in birds

• Jugular

• Brachial (wing)

• Metatarsal

When would you not use a jugular vein for bloods?

If the patient has a clotting problem

Equipment needed for blood samples

• Needles (depending on animal depends on gauge)

• Syringes

• Blood tube/vacutainer

• Hibiscrub

• Spirit

Advantages of using a bigger needle

• Better flow

• Minimal pressure required

• No haemolysis

• Increased bleeding risk

Advantages of smaller needles

• Haemolysis

• Lower bleeding risk

• Higher pressure required

• Slower flow- higher clotting risk

Haematology terminology

• RBCs-red blood cells 

• HCT- haematocrit aka PCV

• HGB- haemoglobin (x3 is PCV)

• RETIC- reticulocyte

• WBC- white blood cells

• NEU-neutrophils

• LYM-lymphocytes

• MONO-monophils

• EOS-eosinophils

• BASO-basophil

• PLT-platelets

What does polycythaemia mean

High RBCs

What does anaemia mean

Low RBCs

What does leukocytosis mean

High WBCs

What does leukocytosis mean

High WBCs

What does leukopenia mean

Low WBCs

What does thrombocytosis mean

High platelets

What does thrombocytopenia mean

Low platelets

What can BioChem tell us

• Electrolytes

• ALT/ALP

• Kidney values e.g. creatine and urea

• Bile acids

  • Thyroid markers (T4)

Plasma vs serum

Plasma

• Anticoagulated blood

• Contains fibrinogen or clotting factors

Serum

• Coagulated blood

• Doesn’t contain fibrinogen or clotting factors

What are the 2 plasma proteins

• Albumin

• Globulin

What are the 6 electrolytes

• Magnesium (MG2+)

• Sodium (Na+)

• Phosphate (PO4)

• Calcium (2+)

• Chloride (CL-)

• Potassium (K+)

Glucose

• Neonates and small patients are at risk of hyperglycaemia

  • Hyperglycaemia caused by diabetes

Lactate

• Patients with high lactate have low BP and poor perfusion

• Oxygen delivery is compromised so tissues anaerobically respire producing more lactate

  • E.g. GDV, hypovolaemic shock, septic patients

Renal biomarkers

• Urea

• SDMA

• Creatinine-increase only occurs when 70% of nephrons stop working (stop producing urine)

Hepatic biomarkers

• AST

• ALKP

• ALT

• Ammonia

• Bile acids

• Bilirubin

• Y-GT

Where are the hepatic biomarkers found

What are the 2 fats

• Triglycerides

• Cholesterol

Pancreatic biomarkers

• Amylase

• Lipase

• FPLI (snap test)

• CPLI (snap test)