Clinical Pathology Flashcards
What to check with regards to what tubes to pick when collecting blood?
- Chek what anticoag present in your tube (EDTA pink in UK)
- Check where fill line is
- Check tubes are in date
describe EDTA tubes
- Haemtology
- K2 EDTA or NaK-EDTA
- Fibrinogen
- PCR
- Fluids for cytology
Describe Citrate tube (purple)
- Coagulation profile
Fibrinogen
describe Plain Tube? (brown? )
- Biochem
- Endocrinology
- Serology
- Fluids for culture
Describe Heparin tube ? (orange)
- Lithium Heparin
- Biochem
- PCR
Fluoride oxalate tube?
Glucose
What order do you want to fill tubes after collecting blood?
- EDTA - haem (heparin for most non-mammals)
- Citrated (if needed)
- Plain/heparin
- Fluoride oxalate
How can we collect urine?
- Free catch
- Cystocentesis
- Catheter
Which tubes for urinalysis?
- Plain universal -> USG, Dipstick, Sediment
- Boric Acid tiube -> culture
when to take blood sample?
- Just after feeding will affect )> creatinine , cholesterol (starve for 8-12 h helpful)
- Sample when CLs most apparent (e.G. post seizure)
- If monitoring therapy -> trough or peak samples rq
What goes on the submission form with a sample?
- Signalement -> species, breed, age, sex, neutered or not
- History - presentation? exam? ddx? current therapies?
How to submit a sample?
- Ensure no leaks
- Check labeled correctly & marked as pathology sample
- Consider is hazardous
- ensure return address on package
Why is species relevant?
- Different machine settings
- Difference ref intervals
- Doiffferent clinical decision limits
Greyhounds?
- Variable haematology parameters
- Variable biochemistry parameters
- Variable endocrinology parameters
Why is Age relevant?
- HAemtology -> switch from fetal circulation
- Biochem > bone growth & organ development
- Endo -> variations
Relevance of sex?
hormones can influence tumour growth
Medications relevance?
- Steroids - stress leukogram
- Sedatives - sequestration of populations in the spleen
- Phenobarbitone - neutropenia
INC or DEC Erythrocytes called what?
Polycythaemia or Anaemia
Platelet variations called?
Thrombocytosis / thrombocytopaenia
What toxic changes can we see?
- Cytoplasmic change
- Dohle bodies
- Foamy cytoplasm
- Basophilic cytoplasm
- Indicates inflammatory response
What does band neutrophil to metamyelocyte look like?
- Left shift
- Smooth nucleus
- Metamyelocyte less elongated
- Indicates infalmmatory response
Rabbit blood differences?
- Heterophils vs neutrophils (granules stain much brighter than most mammalian neutrophiols
- Small and large lymphocytes may be observed
What does inc & dec MCHC mean?
Hypochromasia or hyperchromasia
inc & dec MCV?
Microcytosis vs MAcrocytosis
Inc RDW?
Anisocytosis
Blood loss can be due to 2 things ..?
Blood loss or Haemolysis
Describe a nonregenrative anaemia?
Down 30% dog or 20% cat (mild) ->
- Anaemia or chronic or inflammatory dx
- Normocytic normochromic
below 20% -> Moderate -> dec erythropoietin - CKD
-> Dec production
-> BM dx
Marked -> below 15%
What is this anaemia pattern
- NORMOCYTIC
- Normochromic
- Non regen
- Mild
- anaemia of chronic or inflammatory dx
What is this anaemia pattern?
- Macrocytic
- Hypochromic
- Often regen
nb ould also be in vitro storage artefact
What is this anaemia pattern?
- Microcytic
- Hypochromic
- Iron deficiency
- PSS
serum = ?
serum = plasma - clotting factors
( only attained after leaving to clot for min 30 mins
Serum vs plasma?
Serum:
- Separated serum less liekly to have clots that interfere with results
- If separated within 2 hrs analytes tend top be more stable
Plasma:
- Separated and run immediately
- Some tests may not be suitable with some anticoagulants
When might our result not be significant?
Presence of haemolysis, lipaemia and icterus may affect results
-> Result may directly be affected e.g. ALT & K+ may be released from lysed R£BC elevating serum values
-> values affected indirectly : inc turbidity may alter spectrophotometry
What age & breed variaitons to consider?
- ALp higher in growing animals due to higher boen isoform
- Globulin levels are often lower in enonates
Describe Proteins
- Albumins, globulins and assorted
- Predom synthesized by liver
- Responsible for oncotic pressure
- Machine measures TP and albumin (globulin calculated by subtraction from TP)
Describe Albumin
-One of smallest proteins commony found in plasma/ serum
- Synthesed in liver
- Inc seen with dehydration
- Dec may reflect:inc loss OR dec production (neg acute phase response protein)
Describe GLobulins
- Increases - antigenic stimulation (also with some neoplasia)
- Dec due to: loss (haemorrhage, PLe, PLN)
Describe use of protein electrophoresis?
- Used to differentiate types of hyperglobinaemia
- Monoclonal - neoplasia
- Polyclonal - inflammation e.G. FIP in the cat
Describe Urea & Creatinine?
Azotaemia = inc of both
Can be renal, prerenal or post renal
assess with hydration status of patient and USG at time of taking seurm
Pre-renal azotaemia?
- Dehydration - most common
- High protein meal -> starve for 12 h to reduce interference
- BUT GI haemorrhage may result in elevations - essentially high in protein meal
Post renal azotaemia?
- Obstruction - full bladder, poss history of stranguria
- Ruptured bladder - post obstruction or RTA
Sample peritoneal fluid assess serum and fluid urea creatinine
Renal Azotaemia?
- Azotaemia with isosthenuria
- Most concerning finding
- Due to kidney dx, acute, chronic
Which liver enzymes show hepatocellular damage?
- ALT
- GLDH
- SDH
- (AST/ LDH)
What values show cholestasis?
- ALP
- GGT
Describe ALT
» Hepatocellular
* But present in most cells
» Transient increase may be seen in RTA’s, ?liver damage, or muscle
» Elevations may not correspond with degree of liver damage
Describe ALP
» Sensitive but not specific for cholestasis
» Released from brush border of bile ducts
» Other isoforms/enzymes
* Bone isoform, present in growing animals and in those with bone pathology
* Canine – steroid induced isoform/enzyme
* Gut isoenzyme –usually not noted as transient
GGT ?
- Specific test for cholestasis and biliary tree disease
- Less sensitive than ALP
- May be increased in neonates due to colostrum intake
- Increases have been seen with steroids
Bilirubin?
- Inc may be pre-hepaticn post hepaticn hepatic
- Pre-hepatic - >haemolysis, check HCT
- Hepatic, post hepatic - cholestasis
Bile acids?
- Pre and post prandial bile acids - sample feed than sample 2 hrs post feeding
- Functional test for liver - may also be affected by enterohepatic circulation disturbances
Ammonia?
- Functional test for hepatocytes
- Changes seen following exposure to air
- Need to separate EDTa plasma immediately
- If running in house machine exposure to urea reagents may result in increases
Cholesterol?
- Metabolised wihtin the liver
- Inversely proportional to T4
- Inc seen with: hepatic dx, endocrine dx, hypoT & nephroti syndrome
- DEC seen with malabsoprtion & hyperT
CK?
- Muscle cell leakage
- Very marked elevations seen with aortic thromboembolism in cats
- Rapid elevation and relatively short half life - AST has a slower response but elevations may persist for longer
Amylase & lipase?
Elevated with PANCREATITIS
but also:
- dec renal clearance
- other pancreatic dx
- GI obstruction
- Dexamethasone
What is considered more specific for pancreatitis than older lipase assays?
DGGR lipase
Ca & P?
- Regulated by PTH
- elevations in both may be noted in growing animals due to bone metabolism
- Elevations in Ca2+ may be seen with hypercalcemia of malignancy, check that ionised Ca is elevated - PTHrP may be produced by several neoplasms
K, Ca, Cl?
- Itnake from diet, kidney regulates excretion & absoprtion
- Affected by hydration, due to shift of electrolytes between ICf & ECF, so serum values may not reflect ‘total body’ values
- Sodium and Cl usually move together
GLucose?
» May be ingested or synthesised de novo by cells
» Maintained at constant level by storage as glycogen, in liver predominantly
» Glucose uptake and glycogen synthesis promoted by insulin
» Glycogen breakdown promoted by glucagon
Hyperglycaemia?
- Transient- stress, can be up to 17mmol/l – particularly cats and young animals
- Persistent – DM
-> Transient vs persistent : FRUCTOSAMINE reflects glucose previous 2-3 weeks on av
Hypoglycaemia?
- Spurious due to storage or haemolysis in vitro
- Insulinoma
- Hepatic disorder
- Sepsis
- Addisons
What do we see on Dipstick eval?
- pH
- Protein
- Glucose
- Ketones
- Bilirubin
- urobilinogen
- haemoglobin
USG?
from refractometer, make sure properly adjusted - pure distilled water should be 1.000
USG values?
» Interpret with volume of urine production
» Isothenuric 1.007-1.012
» <1.007 hyposthenuric
» Good concentration
» >1.035 (1.040) feline
» >1.030 canine
» >1.020 equine/large anima
Sediment exam?
- Crystals
- Casts
- Cells
- other
