Exam 7 L.1 Flashcards
Regenerative anemia
The most useful marker of regeneration is increased number of reticulocytes
-immature, non-nucleated erythrocytes
NOTE: remember that and cats reticulocytes are not useful in determining RBC regeneration
Reticulocytosis
1) takes 2 to 4 days to develop after blood loss/anemia event
2) peaks between 4 and 7 days
Reticulocyte percentage
The percentage of RBC that are reticulocytes (accounts for anemia)
CRP = RP x (Patient’s HCT/Average HCT for species)
Average HCT: dog = 45% cat = 40%
If the corrected count > reference interval, then this indicates regenerative anemia
- reference interval for RP: dog = 0-1% cat = 0-0.4%
Other indicators of regeneration
1) increased MCV
2) increased RDW
3) decreased MCHC
4) polychromasia
5) Howell - Jolly bodies (nuclear remants - little purple dots in the RBC)
6) appropriate rubricytsosis (nucleated RBC in presence of anemia)
Heinz bodies
Indicate oxidative damage to RBC’s
Schistocytes
DIC, hemangiosarcoma
Acute blood loss anemia
1) initially, peripheral vasoconstriction and tachycardia occur
2) regional blood flow to the skin and spleen is curtailed to protect perfusion to the brain, heart, and viscera
3) blood loss >30-40%: cardiac output decreases, hypotension with CV collapse
- animal is immobile with rapid/thready pulse
- cold skin and extremities
4) blood loss >50%: shock and death before changes in HCT and plasma proteins are seen
5) INITIALLY PCV AND TOTAL PROTEIN ARE NORMAL
- all blood components are lost in similar proportions
- splenic contraction plays a role early in the process, causing a transient increase in PCV
Acute blood loss anemia
1) total protein will begin to rise to-3 days after a bleed (as long as bleeding has stopped)
2) CBC is normal in about 2 weeks
Remember
With sudden hemorrhage, immediate effects of volume depletion are as important as the loss of circulating RBC’s
-A HEALTHY, NORMOVOLEMIC ANIMAL MAY TOLERATE HCT OF 5-10%
Iron deficiency anemia
Chronic external blood loss is a major cause of iron deficiency anemia
-initially anemia is regenerative but can become non-regenerative over time
Chronic blood loss anemia: causes
1) external parasites: fleas, hookworms
2) G.I. bleed
3) inflammatory bowel disease
4) frequent phlebotomy in small patients!
Presentation of chronic blood loss anemia
Develops over weeks
exercise intolerance
pale mucous membranes, bounding pulses, systolic heart murmur
with stress, can suddenly decompensate and die
decreased synthesis of hemoglobin due to iron deficiency
——– thrombocytosis often accompanies iron deficiency
Treating chronic blood loss anemia
1) these animals are NORMOVOLEMIC with an increased cardiac output
2) stop ulcerogenic drugs
3) control of ecto- and endoparasites
4) surgical resection of bleeding tumor
After underlying condition is corrected:
1) iron supplementation: first give iron parenterally (IM)
- then supplement orally with ferrous sulfate up
Non-external blood loss anemias
1) bleeding into pleural, peritoneal, or pericardial spaces can occur
2) these animals can auto transfuse, with resorption of approximately 80% of the RBC’s within 1-2 weeks
Normal RBC lifespan
Dogs = 120 days Cat = 70 days
