Week 2 - Anemia Part 1 Flashcards
Define anemia.
Decrease in red blood cell (RBC) mass.
How is RBC mass measured?
RBC mass measured by PCV/HCT, RBC count, and Hgb concentration
What are the clinical signs of anemia?
- Pale mucous membranes
- Lethargy, reduced exercise tolerance
- Increased capillary refill time (>2 seconds)
- tachypnea (Increased respiratory rate)
- Dyspnea (shortness of breath)
- Tachycardia (increased heart rate)
- Murmurs if <20% (increased turbulence)
What are the non-specific clinical signs of anemia?
–> Probably related to underlying illness
* Weight loss
* Fever
* Lymphadenopathy
* Polyuria
* Polydypsia
Anemia Signs associated with blood destruction are?
- Splenomegaly
- Icterus (jaundice)
- Hemoglobinuria (HgB in urine even after centrifugation).
Duration of onset of anemia may impact clinical signs. How?
May impact the severity of the clinical signs
* SLOW onset –> less severe
* RAPID onset –> more severe
How do you approach an anemia patient?
- Lab evaluation
* Red blood cell mass (PCV)
* Mean cell volume
* Reticulocyte count
* Total protein - History
- Physical examination
How is anemia classified?
- Based on the response of the bone marrow
* Regenerative
* Non-regenerative - Based on RBC Indices (size and chromasia)
* MCV & MCHC - Based on pathophysiologic mechanisms
* Blood loss (hemorrhage)
* Accelerated RBC destruction (dec. RBC life span) by Intra- or Extravascular hemolysis
* Reduced or defective erythropoiesis
What can be seen in this image?
Normal RBC in a horse
M = macrocytes
What are the major causes of regenerative anemia?
- Blood loss
- Blood destruction/hemolysis
How can blood loss lead to anemia??
What is the difference between acute and chronic blood loss?
b/c not enough iron to replenish.
What are two major characteristics of acute blood loss?
- Protein decreases along with PCV
* Usually returns to normal within one week if not
ongoing blood loss. plasma protein decreases together but with time the protein will adjust itself. - Normal Erythrocyte morphology –usually-
* Exception in dogs with Hemangiosarcoma; acute blood loss due to bleeding. When rupture –> large amounts of blood loss
What cells are reported in cases of acute blood loss? Identify them in the image below
Acanthocytes and schistocytes –> Hemangiosarcoma
Or in blood loss?
List some examples of acute blood loss
- Trauma & Surgery
- Coagulation disorders
- Bleeding tumors- Hemangiosarcoma
- Thrombocytopenia (<25,000/ul)
- blood loss does not cause thrombocytopenia. Thrombo causes blood loss
How are RBC’s regenerated?
How long does this process take?
See below
List some examples of chronic blood loss.
In which part of the body is it most common to lose blood?
- Gastrointestinal (GI) ulcer
- Bleeding GI tumor
- Parasites (blood consuming)
- Hookworms, whipworms
Blood loss via the intestine is the most common
What parasite is pictured below?
Describe its size.
In which part of the body can this parasite be found? How does it impact the host?
Ancylostoma caninum - Hookworm
small parasite
live in GI tract of dogs and cats
attaches to stomach lining and ingests blood directly
Chronic blood loss induces deficiencies, especially in adults. We see iron deficiency anemia in nursing animals - why? In adults as well - why?
- Nursing animals due to Inadequate intake
- In adults, almost always due to CHRONIC blood loss
What lab findings do we see in iron deficiency anemia?
- Microcytosis = low MCV
- Reticulocytes are present and also have decreased MCV
- RDW usually increased (anisocytosis aka variation of RBC)
- This is a Calculated parameter: Index of degree of RBCs anisocytosis - MCHC often normal (Unlike in humans)
- Anemia usually regenerative, unless concurrent
anemia of inflammatory disease - Thrombocytosis common having an elevated level of platelets in blood