Polycythemia Flashcards
Polycythemia is the opposite of…
Anemia - PCV is abnormally high for polycythemia
-increased red cell concentration (relative or absolute)
Relative increase in red cell concentration means…
Red cell mass is NOT increased but:
- decreased plasma
- splenic contraction - redistribution
Hemoconcentration is an example of relative increase in red cell concentration. What causes this?
dehydration and fluid shifts
-water loss
Redistribution of RBCs is an example of relative increase in red cell concentration. What causes this?
excitement and exercise (Epinephrine release)
Absolute increase in red cell concentration means…
increased erythropoietin –> increased RBC production
Erythropoietin increases when oxygen is…
low.
Appropriate erythropoietic production increase is bc of…
Chronic Hypoxia
- heart probs
- lung probs
- altitude increase
Inappropriate erythropoietin production is bc of…
hypoxia in the cells that produce erythropoietin
due to: renal tumors/abscess/infarcts
Primary (Polycythemia vera) erythrocytosis is an example of what type of red cell production?
Absolute increase…
Increase in leukocyte and platelet production.
Increased Red cell production ONLY in Animals.
-myeloproliferative disease
Polycythemia vera is what type of disorder?
Myeloproliferative disorder
4 yo dog presents with lethargy and vomiting - it is acutely ill.
PCV 75% (37-55)
Retics 0 (0-60)
T Pro 9.8 (6.0-8.0)
Gluc 220 (65-122) BUN 145 (7-28) Creat 6.5 (0.9-1.7) Ca 6.8 (9.0-11.2) Phos 12.2 (2.8-6.1) T Prot 9.6 (5.4 - 7.4) Alb 5.2 (2.7-4.5) Glob 4.4 (1.9-3.4)
UA - USG 1.011 Prot +1 Gluc +2 pH 5.0 Sediment: Few RBCs, leukocytes, many calcium oxalate crystals
Diagnosis?
What gives it away?
Acute Renal Failure!
Giveaway: calcium oxalate crystals
Notes: Hyperglycemic - consider diabetes
Hypocalcemic - consider ethylene glycol toxicity
hyperphosphatemic - Get rid of Ph through the kidneys –> Decr. GFR
Isosthenuric - He is losing water in his urine bc he cannot concentrate.
Azotemic/Uremic
Dehydration
High PCV is the least of his worries.
Primary worry?:
severe Renal tubular epithelial cell damage secondary to metabolites of ethylene glycol
Increase in PCV and T pro means you are probably dehydrated. Treat with fluids and everything will go back to normal.
Truth!
T Prot on Biochemical profile vs. T Pro on CBC…
w/ CBC estimating T Pro by measuring with a refractometer.
w/ Chemistry you are measuring chemically.
The difference normally is fibrinogen.
Expect T Pro to be a little lower on the Biochem Profile!
The ONLY thing that causes an increase in Albumin is…
Dehydration!
T Pro - Alb =
Globulin
Ingestion of (primary ingredient in coolant and antifreeze) Ethylene glycol is probably the most common cause of…
acute renal failure
Metabolites of ethylene glycol are toxic –> Oxalic acid which combines with Ca2+ to form what? On the chemistry it will cause…
Calcium Oxalate Crystals
Hypocalcemia - Ca binds to the oxalic acid.
Can you concentrate urine with acute renal failure?
Nope - Isosthenuric
8yo dog, PU/PD, lethargy PCV 69 (37-55) Retics 70 (0-60) T Pro 7.5 (6.0-8.0)
What tests do you want to do?
Is his PCV increased due to hypoxia?
Rule out Dehydration - normal T Pro
Arterial Oxygen - Normal
Serum Erythropoietin - Increased
Increased serum erythropoietin in an animal that is NOT hypoxic….think about?
Inappropriate Erythropoietin production.
Think about: Kidney lesion - mass/cyst
9 yo dog w/ lethargy, PU/PD PCV 71 (37-55) Retics 80 (0-60) T Pro 7.5 (6.0-8.0) Arterial Oxygen - Normal Erythropoietin - Normal
What can you rule out?
What is your most likely diagnosis?
Rule Out:
Dehydration
Inappropriate Erythropoietin Production
Diagnosis: polycythemia vera
7yo dog w/ lethargy, PU/PD PCV 62 (37-55) Retics 100 (0-60) T Pro 6.5 (6.0-8.0 Arterial Oxygen - decreased Erythropoietin - increased
Why the increased Erythropoietin?
Next diagnostic tests?
Diagnosis?
An appropriate erythropoietin production secondary to the hypoxia.
Lung/Heart Imaging
Diagnosis: Hypoxemia
