Introduction to Anemias & Blood Loss Flashcards
Definition of Anemia
- decreased/ dysfunctional RBCs
- decrease in the normal concentration of hemoglobin or RBCs
- considered present if hemoglobin is under lower limit
more a symptom than a disease
total RBC mass (M)
= (# of RBCs produced per day) x ( RBC life span)
Development of Anemia
- RBC loss/ destruction exceeds max capacity of BM RBC production
- BM RBC production is impaired
Screening for Anemia
Relies on the relative Hb and Hct values
Hypervolemia
total blood volume increases (IV fluids etc)
Hb & Hct are falsely decreased
Hypovolemia
occurs in dehydration
Hb & Hct are falsely elevated
Generic Anemia Symptoms
Pallor -pale 1st symptom fatigue headaches faintness slight fever all due to diminished delivery of O2
Factors that lead to a Diagnosis of Anemia
Patient History physical examination symptoms hematology values! other lab findings
Patient History (in diagnosis)
patient diet, drug ingestion, occupation, family history etc
Physical Exam (in diagnosis)
skin - pallor/jaundice
splenomegaly (enlargement of spleen)
hepatomegaly (enlargement of liver)
Hematology Values (in diagnosis)
CBC = Hgb, Hct, MCV, MCH, MCHC, Retic Count
RBC morphology
2 major classifying schemes for Anemias
Morphological (Wintrobe) - based on RBC indices & retic count
Pathophysiological/ functional - based on lab results
Wintrobe classification
morphological classification based on cell size & color
microcytic (100 fL)
hypochromic (36)
Pathophysiological Anemia Classification
4 major categories: blood loss Impaired production of RBCs Increased Destruction of RBCs Defects in Hemoglobin
Blood Loss Anemias (2)
Acute
Chronic
Acute Blood Loss Anemia
traumatic conditions
associated with hypovalemia
3 major steps of acute blood loss = immediate phase, delayed phase, regenerative phase
Immediate Phase of Acute Blood Loss Anemia
initial blood loss creates a fluid shift
Hgb & Hct may not be decreased at the time
Delayed Phase of Acute Blood Loss Anemia
IV support
Hgb, RBC, Hct will be decreased
Normochromic, Normocytic anemia
Regenerative Phase of Acute Blood Loss Anemia
3-5 days
BM responding to anemia with increased Reticulocytes
Summary of Acute Blood Loss Anemia
cause- trauma blood volume distruption - yes iron deficiency - no Hct- initially normal WBC count- increased platelets - increased retics- initially normal then increased
Chronic Blood Loss Anemia
associated with GI tract disorders, heavy menstruation, urinary tract abnormalities
slowly developing anemia
Adaptions to Anemia
increased in oxygenated blood flow- up cardiac output, up circulation rate
increase in 02 utilization by tissue - increase 2,3 BPG, decrease 02 affinity of Hgb in tissues (bohr effect)
Summary of Chronic Blood Loss Anemia
Normochromic, normocytic cause- GI tract, menstruation, urinary tract blood volume distruption - no iron deficiency - yes Hct & hgb - decreased WBC count - normal Platelets - normal Retics - Increased
