ClinPath1 Flashcards
CBC Review
- PVC
- TP
- RBC
- WBC
- Hgb
- Indices
- Differential
- Platelet estimate
Reticulocyte Count
– immature RBC- still in the bone marrow
- Measurement of a regenerative response – larger amount of polychromataphils
- Use methylene blue- (one drop only) blood sits with blue for about 10 minutes, smear, air dry
- Reticulocytes will have dark spots or lines in them- RNA, basophilic stippling
- Count # reticulocytes/1000 RBC
two types of reticulocytes in cats
a. Punctate: 2-8 basophilic stipples
b. Aggregate: Basophilic lines – more of the typical reticulocytes
c. Only count the aggregate ones
Nucleated Red Blood Cells
- CBC machine lyses everything without a nucleus (mature RBC, platelets)
- If the RBC has a nucleus, it is not lysed, therefore counted as a WBC (artificially elevating WBC count)
- But, we don’t know we have N-RBCs until differential
- If N-RBC are seen on the differential, keep track of how many, record as #N-RBC/100 WBC
- But then must correct the WBC count and absolute numbers on differential
Corrected white blood cell count (math)
- Observed WBC count (X) 100
100 + N-RBC
Fibrinogen Levels
- Fibrinogen levels increase during inflammation
- Especially useful in dairy cattle for the early signs of mastitis
- Can measure fibrinogen levels by heating plasma 56ºC.
At 56ºC, fibrinogen pellets out (solidifiy), but other plasma proteins stay suspended
Procedure for Fibrinogen Levels
- Spin two hematocrits, measure one TP
- Incubate other hematocrit in 56ºC water bath for 5 min
- Respin heated hematocrit, measure TP
- Fibrinogen level is the difference between the two numbers. Record as mg/dl
Crossmatching
- Used to determine compatibility for blood transfusions
- Major and minor crossmatch
- Looking for agglutination (RBC clumping) =indicates incompatibility
- Can blood type cats via cards similar to humans. Dogs have 11 types of blood.
Hematomas created by:
o Needle has passed through vein
o Bevel of needle is only partially in vein
o Insufficient pressure on venipuncture site after needle is withdrawn
Blue Top Tube (BTT)
o Sodium citrate – blood clotting times
o Anticoagulant- that is reversible
Gray Top Tube (GTT)
o Not used anymore
o Sodium Fluoride- binds with glucose
o Blood glucose
Reference ranges
(i.e. normal values)
• Derived by measuring the blood chemistry components of clinically normal animals
• Vary w/ species, breed, sex, age, nutrition, geographic region
Enzymes
accelerate reactions, and come out unchanged
• Proteins found inside cells that increase the rate of biochemical reactions
• Very low levels normally present in blood- should maintain an consistent level
o Increased levels usually seen if cells are damaged
Measuring Enzymes
• Enzymes can not be measured directly but must be made to catalyze a chemical reaction whose product can be measured
Substrate + Enzyme–> *Product + Enzyme
*Must be a measurable product complex
• Enzyme concentrations are measured in international units (IU or U)–>amount of enzyme necessary to convert 1 micromole of substrate to product in one minute
Factors influencing enzyme activity
o Temperature o Dehydration o Ultraviolet light o pH extremes o Organic solvents o Heavy metal solvents
Nomenclature of enzymes
o Enzyme names usually end w/ the suffix “-ase”
o The name may indicate its substrate or the type of chemical reaction it facilitates
Liver
o Metabolism of carbohydrates, fats
o Synthesis of albumin, clotting factors
o Secretion of bilirubin
o Metabolism and elimination of toxins, drugs
Enzymes associated w/ hepatocellular injury
o Alanine aminotransferase (ALT)
o Aspartate aminotransferase (AST)
Sorbitol dehydrogenase
ALT
o Alanine aminotransferase
Liver specific in dogs and cats
Not liver specific in horses, cattle, swine- elevation aren’t specially liver
Increased levels may also be due to drug administration (glucocorticoids, anticonvulsants)
AST
o Aspartate aminotransferase
Not liver specific
Increased levels often seen w/ muscle inflammation, hemolysis of blood sample
Sorbitol dehydrogenase
Liver specific in all species
Not routinely measured
Enzymes associated w/ obstruction of bile flow
Alkaline phosphatase
GGT
Bilirubin
Bile Acids
AlkPhos., AP
Not liver specific
Useful in dogs, cats
Not useful in horses, cattle
Increased levels often seen w/ bone injury, rapidly growing animals, use of glucocorticoids and anticonvulsants
GGT
o Gamma glutamyltranspeptidase/glutamyltrans- ferase
Liver is primary source
Works well in small, large animal species
Use of glucocorticoids and anticonvulsants may increase levels
Bilirubin
Derived from hemoglobin released by lysed RBC’s
Increase levels associated w/ increased RBC destruction or liver disease
Avoid exposure of blood sample to light
Lipemia and hemolysis of blood sample may lead to falsely elevated readings
Bile Acids
Substance produced by the liver and secreted in bile to promote the digestion and absorption of fat from the small intestine
Bile acids are reabsorbed from the SI and removed from circulation by the liver
May be increased in portosystemic shunts, chronic liver disease
Kidney Functions
o Eliminates metabolic wastes
o Maintains normal homeostasis (regulates electrolyte, essential organic molecule levels)
o Produces important hormones
BUN
• Blood Urea Nitrogen
o Urea is a metabolic waste that results from amino acid breakdown
o Freely filtered at the glomerulus
False positives may occur if animal ingests a high protein meal prior to test
Azotemia may be due to:
o Increased BUN
Prerenal Abnormalities
Renal Abnormalities
Postrenal Abnormalities
Urea
a metabolic waste that results from amino acid breakdown
Creatinine
o A nitrogen-containing molecule released from muscle at a constant rate
o Freely filtered by the kidney at a constant rate
o Increased levels are due to the same problems that lead to elevations in BUN
The pancreas is an important gland involved in
o Digestion of food
o Regulation of blood glucose
Digestive enzymes produced by the pancreas include
o Amylase
o Lipase
o Trypsin
Amylase and Lipase
o Commonly measured in blood chemistry panels
o Found primarily in the pancreas but also found in other parts of the GI tract
o Increased levels associated w/ injury to pancreatic cells
Elevations 3X’s the normal level considered significant
Pancreatic Lipase Immunoreactivity (PLI)
o A highly specific test for pancreatitis in both dogs and cats
o Also used to diagnose exocrine pancreatic insufficiency (EPI)
Trypsin
o Trypsin-Like Immunoreactivity (TLI)
o Increased levels associated w/ pancreatitis
o Decreased levels associated w/ exocrine pancreatic insufficiency (EPI)
Glucose
o Utilized by body tissues for energy
o Blood glucose level reflects an equilibrium between
The amount of glucose entering the bloodstream
The amount of glucose leaving the bloodstream
o Glucagon and insulin help maintain normal blood glucose levels
