Clinical Pathology 2 Flashcards
What is clinical pathology?
Specialty concerned with diagnosis of disease based on lab analysis of bodily fluids, blood, urine, and tissue
What are some behind the scene things you want happening in the lab your sending your stuff too?
Test validation, test comparison, quality management, reference intervals and development of new methodologies and applications
What should you keep in mind when it comes to testing?
Result comparison should be though carefully about as reference intervals and methodology may differ
Sensitivity and specificity of a test may need to be considered
What is a reference interval?
Mean +/- 2 Standard Devastations
*Varies by lab - equipment, methodology, location, patient (species, breed, age, sex, diet and physiological state)
What does IU equal?
g/L
Where can laboratory error occur?
- Preanalytical (before it gets to the lab)
- Analytical (Lab did wrong/mistake/interference)
- Post-analytical (result go to wrong person)
Where do the majority of lab errors occur?
Preanalytical
What can cause a preanalytical error?
Inappropriate test request, order entry error, error on form, misidentification, labelling, inappropriate container or sample, insufficient volume, inadequate transport or storage, sample processing
How can you prevent pre-analytical errors?
SOP’s, Training Personnel, Communication with clients
What causes analytical error?
Instrument malfunction, reagents, methodology and operator error
How can you prevent analytical errors?
SOP’s, training personnel, automation, monitoring results, certification
What causes post-analytical errors?
Failure of reporting, improper data entry, inappropriate reference interval, incorrect interpretation of results
What are some ways to prevent analytical error?
SOP’s, training personal, automation, communication with clients
What are some keys to remember when running hematology and chemistry?
- Collect in the correct color tube
- Appropriate collection of material and technique
- Ensure correct volume
- Homogenize
- Sample ID
- Request form - hx
- Appropriate shipping/transport
What do you use a Light Blue top tube for and what is the additive?
Coagulation
Sodium citrate (Ca chealates)
What do you use a Red top tube for and what is the additive?
Chemistry
Clot activator/none
What do you use a yellow top tube for and what is the additive?
Chemistry
Gel/clot activator
What do you use a green top tube for and what is the additive?
Chemistry/hematology
Heparin (Wont clot)
What do you use a purple top tube for and what is the additive?
Hematology
EDTA (bind)
What do you use a grey top tube for and what is the additive?
Glucose/lactate
Sodium Fluoride
What do you use a black top tube for and what is the additive?
Blood Culture
Culture Media
What are some common artifacts in hematology?
Erythron
Heinz Bodies - increase MCH, MCHC, reticulocyte, platelet
EDTA - Decrease MCV and HCT
Leukon
Old sample
-Dohle bodies, decrease WBC, decrease neutrophils, increase band and change in lymphocyte
Platelets
Clumps, Ghost Cell, Organism
What causes hemolysis as artifact?
-Species and method dependent
-Increase MCH, MCHC, Platelets, CK, P, AST, LDH and MG
-Decrease PCV
-TP refractometry
What causes Icterus?
no interference in CBC, spectral properties and ability to react - decrease creatine and protein
What makes lipemia an artifact?
Triglycerides, chylomicrons, post-prandial, change light scattering, chem analytes, assay depended (TP, Increase platelet and HGB, volume displacement)
What are some urinalysis artifacts?
Delayed analysis - altered urine pH, microbial proliferation, degradation formed elements, chemical analyties calcium oxalate and magnesium ammonium phosphate
- bacteria in free catch
What should you always do to prevent artifacts in cyctology?
- Always use gloves to handle slides
- Never reuse slides
- Slides should air dry (prestain, unstained and not heat fixed)
- Stain slides ASAP
- Never send slides with formalin
- provide relevant history
- always be precise in location of lesion
What kind of quality assurance does the lab run?
Preanalytical - reject poorly collected samples, incorrect tubes, ones not shipped correctly
discard reagents, reject when controls are out
If lab data doesnt make sense based on history and exam what should you do?
Don’t trust it
