Clinical Pathology Flashcards
1
Q
EDTA sample tubes
A
- Haematology - preservation of cells, quantitative examination + qualitative examination (blood smear)
- K2EDTA or NaK-EDTa
- Fibrinogen (some labs)
- PCR (some labs/assays, may need heparin, EDTA/heparin anticoagulant interfere w/ PCR)
- Chelates Ca2+, Mg2+, Fe2+ -> stops clotting
- Fluids for cyto
- Pink tube
2
Q
Citrate sample tube
A
- Coagulation profile
- Fibrinogen (some labs)
- PT
- APTT
- D-dimers
3
Q
Plain sample tubes
A
- Biochem
- Endocrinology
- Serology
- Fluids for culture - white top tubes
- Should be at room temp 15 - 20 min until full clot formation has occurred
4
Q
Heparin sample tube
A
- Lithium heparin
- Biochem (+ haematology - exotics)
- PCR (some labs/assays)
- Unsuitable for haematology - results in poor leucocyte staining on blood films
5
Q
Fluoride oxalate sample tube
A
- Glucose - prevents glycolysis/oxidation of glucose
6
Q
When to take urine sample
A
- Starve 8 - 12 h - eliminates effects of glucose, creatinine + cholesterol values from feeding inc
- When clinical effects most apparent - e.g. post-seizure
- Monitoring therapy trough/peak samples may be required
7
Q
Factors that affect clin path
A
- Signalment - species - diff machine settings, diff reference intervals, diff clinical decision limits, more concern if inc ALP + ALT in cats
- Breed - e.g. greyhound (inc Hct, inc creatinine, dec T4) - variable haem, biochem + endo parameters
- Age - haem - switch from foetal (larger blood cells) circulation; biochem - bone growth, organ development; endo - age variation - inc ALP, Ca + P in younger animals
- Sex - hormones can influence tumour growth
- Medications - corticosteroids -> stress leucogram; sedatives -> sequestration of populations in spleen -> enlargement, blood pooling -> dec Hct, dec WBC, lower count as in spleen; phenobarbitone -> immune-mediated neutropoenia
8
Q
A
- Erythrocytes
- Inc polycythaemia = phlebotomy
- Dec = anaemia
9
Q
A
- Thrombocytopoenia - < 50 units
- Low no. -> spontaneous H+
- Immune-mediated - extremely low platelet no.
- Mild dec = H+
10
Q
A
11
Q
Toxic changes of neutrophils
A
- Cytoplasmic change
- Dohle bodies (light blue-gray, oval, basophilic, leukocyte inclusions located in the peripheral cytoplasm of neutrophils)
- Foamy cytoplasm
- Basophilic cytoplasm
- Indicates inflam response - infection or sterile (burn or trauma)
12
Q
A
- Band neutrophil to metamyelocyte
- Left shift
- Smooth nucleus
- Metamyelocyte = less elongated
- Inflam response
13
Q
A
- Rabbit + exotics
- HETEROPHILS (don’t have neutrophils) - granules stain much brighter
- May observe small + large lymphocytes
14
Q
A
15
Q
A
- Precursor to macrophages
16
Q
A
17
Q
A
- Inc suggests autoimmune, myeloproliferative disorders - chronic myelogenous leukaemia (CML), primary myelofibrosis; inflammation; allergies; infection
- Value usually approx 0 anyway
18
Q
Dec RBCs
A
- Anaemia
19
Q
Inc RBCs
A
- Erythrocytosis/polycythemia
20
Q
Dec Hct/PCV
A
- Anaemia
21
Q
Inc Hct/PCV
A
- Erythrocytosis/polycythemia
22
Q
Dec MCHC
A
- Hypochromasia
23
Q
Inc MCHC
A
- Hyperchromasia
- Consider that RBC parameters inaccurate
- IMHA - a lot of free Hb in blood, cell agglutination, don’t separate into single cells, clump together
24
Q
Dec MCV
A
- Microcytosis
25
Q
Inc MCV
A
- Macrocytosis
26
Q
Inc RDW (red cell distribution width)
A
- Anisocytosis
- Regenerative response
27
Q
Blood loss
A
- H+
- Haemolysis
28
Q
Mild non-regen anaemia
A
- PCV = 30% (dog), 20% (cat)
- Anaemia of chronic inflam disease
- Normocytic normochromic
29
Q
Mod non-regen anaemia
A
- PCV < 20%
- Dec erythropoietin - CKD
30
Q
Marked non-regen anaemia
A
- PCV < 15%
- Dec production of RBC
- Bone marrow disease
31
Q
A
- Normocytic
- Normochromic
- Non-regenerative
- Mild
- Anaemia of chronic or inflammatory disease
32
Q
A
- Macrocytic
- Hypochromic
- Often regenerative
- NB could also be in vitro storage artefact - swell + take in water
- Polychromatocytes + leptocytes (larger, folded cells)
33
Q
A
- Microcytic
- Hypochromic
- Iron deficiency
- Chronic external haemorrhage
- Portosystemic shunt - alters iron met pathway
34
Q
Serum
A
- Plasma - clotting factors
- Mostly heparin plasma for biochem, may have microclots in heparin
- Obtained after leaving to clot for min 30 min
- Less likely to contain clots that interfere w/ results
- If separated within 2 h, analytes tend to be more stable
35
Q
Plasma
A
- Clotting factors - coagulants - fibrinogen
- Plasma proteins - albumin and globulin
- Separated + run immediately from blood sample
36
Q
What may affect biochem results?
A
- Haemolysis -> release of ALT + K+ from lysed RBC -> inc serum values
- Lipaemia (inc turbidity)
- Icterus (colour substances) -> inc bilirubin