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Flashcards in Exam 7 L.1 Deck (20):
1

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

2

Reticulocytosis

1) takes 2 to 4 days to develop after blood loss/anemia event
2) peaks between 4 and 7 days

3

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%

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)

5

Heinz bodies

Indicate oxidative damage to RBC's

6

Schistocytes

DIC, hemangiosarcoma

7

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

8

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

9

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%

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

11

Chronic blood loss anemia: causes

1) external parasites: fleas, hookworms
2) G.I. bleed
3) inflammatory bowel disease
4) frequent phlebotomy in small patients!

12

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

13

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

14

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

15

Normal RBC lifespan

Dogs = 120 days
Cat = 70 days

16

Extravascular hemolysis

1) spleen, bone marrow, and liver breakdown RBC's
2) assumed to be the mode of destruction of senescent RBC's in healthy animals

17

Extravascular hemolysis

1)*most common*
2) RBC's are degraded WITHIN macrophages, so no hemoglobin is released from the cytoplasm
-so, there is NO hemoglobinuria or hemoglobinemia
-hemoglobin is broken down into hemosiderin and bilirubin
3) extravascular hemolysis is accompanied by bilirubinemia and bilirubinuria

18

Intravascular hemolysis

1) less common
2) a result of membrane permeability changes or cellular fragmentation
3) RBC's are lysed within circulation
4) hemoglobin is directly released into the blood
5) hemoglobinuria ensues when the amount filtered through the kidney exceeds the limited capacity of the tubule to resort hemoglobin dimers

19

Hemoglobinemia and hemoglobinuria ==>

Associated with INTRAVASCULAR hemolysis*

Spend the urine down:
-hemoglobin in urine ==> after spinning the urine stays red
-blood in the urine ==> after spinning there is a pellet of blood at the bottom of urine tube

20

Hemolytic anemia

Usually very regenerative
macrocytic, hypochromic