Intro to clinical pathology Flashcards
What is the use of clinical pathology analysis?
Monitoring production/performance
Monitoring during critical periods
Special purposes e.g., transport, selling etc.)
What is clinical pathology?
The development, application and interpretation of laboratory procedures for:
- establishing a diagnosis and/or prognosis
- monitoring of treatment in sick animals
- monitoring animal health
What tests does clinical pathology involved?
Haematology
Clinical biochemistry
Cytology
What fluids can be tested in clinical pathology?
blood (blood, serum, plasma)
urine
fine needle aspirates (FNAs)
effusions
cerebrospinal fluid
lavages (e.g., BAL)
synovial fluid
What type of anticoagulant blood tubes are there and what tests are they used for?
What type of blood tube should be used for measuring Ca+
Heparinised plasma
No other anticoagulants as they cause Ca+ levels to decrease
What factors should be considered when deciding which order to fill blood tubes?
can’t risk bacterial contamination from other tubes for a blood culture
can’t delay a citrate sample for coagulation because can’t risk coagulation starting before sample hits the citrate
don’t want to risk contaminating our chemistry samples with EDTA
Label these canine samples by their plasma colour
How can haemolysis be caused when taking blood?
Using a needle too small
Dispensing blood sample through needle
What is the effect of causing haemolysis of blood samples?
INCREASES in plasma/serum values of some compounds/ enzymes due to their higher concentration in the RBC
INTERFERES determinations by colorimetry or interference in chemical interactions
What is the effect of lipaemia on blood samples?
Increase in total lipid, triglycerides and cholesterol
Determinations are affected or cannot be carried out due to presence of extra lipid fractions
Turbidity impacts colorimetry
What are pre-analytical sources of errors in lab results?
Patient preparation
Sample preparation
Shipping
How can lipaemia be prevented in blood sampling?
Fast patients appropriately
Describe analytical sources of errors in lab results
Appropriate equipments/reagents
Quality control (e.g., equipment working?)
Describe post-analytical sources of errors in lab results
Results go to wrong place or labelled as wrong patient
Inappropriate interpretation
Diagnostic sensitivity and specificity
What factors should be considered when validating an analytical technique?
Precision
Accuracy
Specificity
Sensitivity
Analytical Range
Define specificity of an analytical technique
ability of a technique to measure one single analyte in a complex solution
Define precision of an analytical technique
ability of a technique to give the same result for repeated measurements of the same specimen with the same technique
Define accuracy of an analytical technique
ability of a technique to give the true value (usually unknown) of the analyte measured
Define analytical range of an analytical technique
interval between the lowest and highest concentrations that the technique can measure
