Anemia - Decreased RBC Production (complete) Flashcards Preview

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1
Q

What are some of the major causes for anemia related to RBC underproduction?

A

1) Chronic infections
2) Chronic non-infectious, inflammatory disease
3) Malignant disease
4) Lead intoxication
5) Renal insufficiency
6) Endocrine disorders

2
Q

What are the typical clinical findings for chronic infections as they relate to anemia w/ decreased RBC production?

A

Depends on underlying disease

Signs/symptoms: pain, cough, swelling

May include: fever, arthralgias, arthritis, fatigue

3
Q

What are the typical lab findings for chronic infections as they relate to anemia w/ decreased RBC production?

A
  • Mild/mod anemia
  • May be normochromic/normocytic or microcytic w/ hypochromia
  • decreased serum Fe
  • decreased TIBC
  • normal to ^ ferritin
  • decreased EPO for Hct
  • decreased retic count
4
Q

What are the typical clinical findings for lead intoxication as it relates to anemia w/ decreased RBC production?

A
  • Personality changes
  • Irritability
  • Headache
  • Weakness
  • Wt loss
  • Abdom pain
  • Vomiting
5
Q

What are the typical lab findings for lead intoxication as it relates to anemia w/ decreased RBC production?

A
  • Mild/mod anemia
  • decreased retic count
  • microcytosis/mild hypochromia
  • Basophilic stippling
  • ^ Zn protoporphyrin
6
Q

What are the typical clinical findings for renal insufficiency as it relates to anemia w/ decreased RBC production?

A
  • Fatigue
  • Pallor
  • Decreased exercise tolerance
  • Dyspnea
  • Tachypnea
7
Q

What are the typical lab findings for renal insufficiency as it relates to anemia w/ decreased RBC production?

A
  • Usually no anemia til creat clearance 2-2.5 mg/dL
  • Mod/severe anemia
  • Normochromic
  • Normocytic
  • Decreased retic count
  • EPO deficiency — decreased production
8
Q

What are the typical clinical findings for endocrine disorders as they relate to anemia w/ decreased RBC production?

A
  • hyper- or hypoactivity
  • weight gain/loss
  • systemic symptoms
  • skin/hair/nail changes (hypo- or hyperthyroidism)
  • Nausea
  • Vomiting
  • Dehydration
  • Weakness
  • Circulatory collapse
9
Q

What are the typical lab findings for endocrine disorders as they relate to anemia w/ decreased RBC production?

A
  • Mild anemia
  • Hypothyroidism: normochromic, normocytic (can be micro- or macrocytic)
  • Hyperthyroidism: normocytic (may be micro)
  • Adrenal: mild anemia, normocytic

ALL decreased RETIC COUNT

10
Q

Describe the pathophysiology of anemia related to chronic disease for malignancies and sepsis

A
  • TNF decreases Fe availability from stores
  • Also, decreases production of EPO
  • INF-beta inhibits erythropoiesis

overall, decreased RBC production

11
Q

Describe the pathophysiology of anemia related to chronic disease for chronic infections/inflammation

A
  • IL-1 decreases Fe metabolism
  • Also, decreases EPO production
  • INF-gamma inhibits erythropoiesis

Can’t use Fe stores —» decreased RBC production

12
Q

Describe the rationale and indications for the use of erythropoietic in the management of underproduction anemia

A

Used when….

1) there is an absolute deficiency
2) EPO levels are decreased out of proportion to the degree of anemia

13
Q

Explain the biochemical basis for B12 and folate deficiency leading to macrocytic anemia

A
  • Both are critical cofactors for normal hematopoiesis (downstream product required for normal DNA synthesis)
  • Deficiencies affect RBC precursor maturation process in BM

Cells increase in size, arrest in S phase of mitosis —»> destruction (ineffective erythropoiesis)

14
Q

What are the dietary sources of B12?

A

1) Meat
2) Eggs
3) Milk

15
Q

What are the dietary sources of folate?

A

Widespread

1) cereals, bread
2) fruits, veggies
3) meats, fish
4) breast milk (one of the reasons why breastfeeding is so important)

16
Q

Describe the mechanisms for absorption, transport, and duration/location of storage for B12

A

Absorption:

  • Intrinsic factor (IF) binds to B12 in the stomach
  • In the ileum, B12 is absorbed and released by IF

Transport:

  • Transcobalamin binding protein II (TcII) binds to B12
  • Transport to the liver for storage
  • Goes to tissues for use (e.g. BM)
17
Q

Describe the mechanisms for absorption, transport, and duration/location of storage for folate

A

Absorption:

  • in the jejunum
  • hydrolyzed, reduced, methylated before distribution/storage

Transport:

  • Tissues for use
  • Liver for storage

Liver stores undergo turnover, secretion in the bile —» reabsorption

18
Q

Describe the findings in peripheral blood and bone marrow in a pt w/ B12 or folate deficiency

A

BM:

  • Megaloblastic changes in RBC and WBC precursors
  • Erythroid hyperplasia
  • Cytoplasmic maturation is normal

PB:

  • Macrocytosis (MCV >97)
  • Ovalocytes
  • Hypersegmented nuclei of neutrophils
  • Poikilocytes and fragmentation (as it progresses)

Severe cases

  • neutropenia
  • thrombocytopenia
  • ^ bilirubin
  • retic count <1
19
Q

Describe the differences between the most common causes of B12 and folate deficiency

A

Both:

  • Malabsorption
  • Metabolic defects

B12:

  • Autoimmune disease
  • IF deficiency
  • Defective transport/storage

Folate:

  • Dietary insufficiency
  • Drugs/toxins
  • Increased demands
  • Increased loss/metabolism
20
Q

Describe the differences in the time to develop B12 and folate deficiency

A

B12:
- Slowly (YEARS)

Folate
- More quickly (WEEKS to MONTHS)

21
Q

Describe the differences between the presence of neurologic abnormalities in B12 and folate deficiency

A

B12:

  • Sensory losses first (numbness, tingling)
  • Loss of proprioception
  • Ataxia, spasticity, gait probs
  • Cognitive/emotional changes

Folate
- infrequent

22
Q

Describe the differences between the lab studies used to make a diagnosis for B12 and folate deficiency

A

Both:

  • ^ MCV
  • Low retic count/index
  • ^ unconj. bilirubin and LDH
  • Neutropenia/thrombocytopenia (in severe cases)

B12:

  • normal/^ serum folate
  • ^ serum methylmalonic acid

Folate:

  • Decrease serum folate
  • normal serum methylmalonic acid
23
Q

Describe the appropriate therapies for B12 deficiency

A
  • IM/SQ injections of B12
  • Daily for 2 weeks
  • then weekly until Hct is normal
  • then monthly for life

Can be given orally if absorption isn’t an issue

For pernicious anemia, large oral doses can overcome absorption issue

24
Q

Describe the appropriate therapies for folate deficiency

A

1mg/day orally or parentally