Flashcards in Introduction and Chemical Pathology Lab Deck (23):
What is ESR and how does it change in infection?
Erythrocyte Sedimentation Rate – the rate at which red blood cells settle out of suspension in blood plasma, measured under standard conditions
ESR increases in infection
Fever is normally a sign of infection. How is it possible for some autoimmune conditions to cause fever?
Fever is caused by the immune system rather than the organism Hence it can occur in autoimmune disease in the absence of an organism
What are the four tube colours for blood collection and what do the colours mean?
Red – no anticoagulant
Yellow – gel – makes the coagulation occur faster Purple – potassium EDTA
Grey – fluoride oxalate (poison)
What are the purple cap bottles used for?
Potassium EDTA keeps the cells alive
It is used when measuring cell counts or anything in general to do with the cells
What are the grey cap bottles used for?
Fluoride oxalate kills the red blood cells – this is used for measuring blood glucose because live red blood cells will consume the glucose
Which bottle is used for measuring HbA1c?
Purple Top – potassium EDTA
What is serum and what is it useful for measuring?
When blood clots and you remove the clot you are left with serum
Serum contains electrolytes but NO clotting factors
How is gel designed so that it separates serum from the rest of the blood?
It is more dense than serum but less dense than cells so it separates the serum from the cells
What can skew the electrolyte measurements of the serum?
Haemolysis – red cells contain a lot of potassium so haemolysis caused by poor collection or the sample being left out too long will result in an increased serum potassium concentration
What does the blue top mean?
It is reversible and used to measure clotting factors
Citrate binds to calcium and prevents clotting
When you get a sample of blood in a citrate bottle, you add just the right amount of calcium to trigger the clotting cascade
What is the blue top used to measure?
Prothrombin time (PT) - measures integrity of extrinsic system
Active partial thromboplastin time (APTT) - measures integrity of intrinsic system
What is creatinine a marker of?
Renal function (GFR) – it is produced by the body at a constant rate and it is excreted at a constant rate provided that the kidneys are functioning normally with little absorbed or secreted
What is urea a marker of?
It is also excreted by the kidneys
How do urea and creatinine change in renal disease?
They increase, urea rises first
What are the three main liver enzymes?
Alanine aminotransferase (ALT)
Aspartate aminotransferase (AST)
Alkaline phosphatase (ALP)
How does albumin change in liver disease?
Albumin levels fall in liver disease
What other cells, other than hepatocytes, contain alkaline phosphatase?
Other than liver disease, when else might ALP be high?
After a fracture – osteoblasts use ALP to build more bone
What is the first thing you do if a patient presents with heart attack type symptoms?
What is measured to confirm a heart attack?
Measure troponin levels
List the main cardiac enzymes.
Creatine Kinase (CK) Aspartate aminotransferase (AST)
Lactate dehydrogenase (LDH)
What else could cause heart attack type symptoms?
A bleeding peptic ulcer