Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PR3154 > IC7- Haematologic disorders > Flashcards

IC7- Haematologic disorders Flashcards

1
Q

Define anaemia. What are the specific numerical values for men and women?

A

It is characterised by a decrease in either Hb or volume of RBCs, resulting in decreased O2-carrying capacity of blood.

Defined as Hb < 13 g/dL in men and < 12 g/dL in women.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the types of microcytic anaemia? (2)

A
  1. Iron deficiency anaemia
  2. Anaemia of chronic disease
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the types of macrocytic anaemia? (2)

A
  1. Vit B12
  2. Folate deficiency anaemia
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How is reticulocyte count useful in checking bone marrow function?

A

If bone marrow responding appropriately: when there is anaemia there is ↑ numbers of immature RBC (reticulocytes) released into the bloodstream

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

If MCV is normal and reticulocyte count is higher, what could it be? (3)

A
  • Acute blood loss
  • Hemolysis
  • Splenic sequestration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe iron deficiency anaemia in terms of MCV, serum ferritin and TIBC.

What do you evaluate for?

A

MCV low, low serum ferritin, high TIBC

Prompt evaluation for blood loss/ causes of ↓ iron absorption

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe anaemia of chronic disease in terms of MCV, serum ferritin and TIBC.

A

MCV low, normal/ high serum ferritin, low TIBC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What should we consider if MCV is high but normal vit B12/ folate levels?

A
  • Hepatic disease
  • Drug-induced anaemia
  • Hypothyroidism
  • Reticulocytosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the possible causes of iron-deficiency anaemia? (2 main causes, each 7 & 3)

A
  1. Decreased iron absorption due to:
    - Atrophic gastritis
    - Celiac disease
    - Gastric bypass
    - H. pylori infection
    - Calcium-rich foods
    - PPIs
    - Medications that ↓ gastric acidity
  2. Blood/ iron loss due to:
    - Pulmonary hemosiderosis
    - Intravascular hemolysis
    - Hematuria or hemoglobinuria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the formulations iron is available in?

What is the dosing and duration of iron for Iron-deficiency anaemia?

A

PO, IV

100-200mg/day
- Requires ~1000-1500mg (cumulative) elemental Fe for complete supplementation, treat for at least 3-6 months

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What may happen if vit B12. deficiency is not treated properly?

A

Neurologic SSx may be irreversible

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is pernicious anaemia?

What are its common causes?

A

Lack of intrinsic factor produced by stomach to absorb vit B12 in small intestine

  • Gastric disruption
  • PPIs, H2RAs, H. Pylori infection
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which drug commonly causes vit B12 and folate deficiency?

A

Co-trimoxazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the treatment for pernicious anaemia? (include route and dosing)

A

Parenteral (IM/ SQ) vit B12

1000 μg OD x 1w f/b
1000 μg weekly x 4w f/b
1000 μg monthly LIFELONG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the treatment for vit B12 deficiency due to other causes apart from pernicious anaemia? (include dosing and route)

A

Parenteral, oral Vit B12

1000 μg/ 2000 μg OD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the common drug causes of folic acid deficiency? (3)

A
  • Co-trimoxazole
  • Phenytoin
  • Phenobarbital
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the treatment for folic acid deficiency? (include route, dosing and duration)

A

PO folic acid (including pts w absorption problems)
1mg OD x 1-4 months or until haematologic recovery achieved

18
Q

Define aplastic anaemia

A

Presence of 2 of the following:
1. WBC count ≤ 3,500 cells/mm3 (3.5 x 109/L)
2. Platelet count ≤ 55,000 cells/mm3 (55 x 109/L)
3. Hb value ≤ 10 g/dL (100 g/L; 6.21 mmol/L) PLUS reticulocyte count ≤ 30,000 cells/mm3 (30 x 109/L)

19
Q

What are the common drugs that cause aplastic anaemia? (6)

Other than drug-induced aplastic anaemia, what else can cause it?

A
  • Furosemide
  • NSAIDs
  • Carbamazepine
  • Cytotoxic chemotherapy
  • Radiation therapy
  • ***Chloramphenicol

Infection

20
Q

Goals of tx of aplastic anaemia? (3)

A
  1. Improve peripheral blood counts
  2. Limit the requirement for transfusions
  3. Minimise risk for infections
21
Q

If aplastic anaemia is very severe, what is the treatment?

A

May require allogeneic hematopoietic stem cell transplantation (HSCT) and immunosuppressive therapy (cyclosporine)

22
Q

What is the tx for aplastic anaemia caused by infection?

A

Prophylactic abx and antifungal agents when neutrophil counts < 500 cells/mm3 (0.5 x 109/L)

Febrile neutropenia: broad spectrum abx

23
Q

What is the tx for aplastic anaemia caused by bleeding?

What can we do if pt is heavily transfused?

A

Transfusion support with erythrocytes and platelets

If heavily transfused → iron chelation therapy with deferoxamine or deferasirox (avoid iron overload)

24
Q

Define neutropenia/ agranulocytosis

A
  • Neutropenia: absolute neutrophil count (ANC) < 1500/ μL
  • Agranulocytosis: absence of granulocytes (ANC = 0); although term often used loosely to indicate severe degrees of neutropenia (ie, ANC < 100, < 200 or even < 500/μL)
25
Q

What are the 3 classes of drugs that cause neutropenia/ agranulocytosis?

Name the specific drugs under each class too

A
  1. Antipsychotics: carbamazepine, clozapine
  2. Abx: β-lactam abx, trimethoprim-sulfamethoxazole
  3. Antithyroid: carbimazole, methimazole, propylthiouracil
26
Q

What is the onset of neutropenia/ agranulocytosis caused by clozapine and other phenothiazines?

A

2-15w after Tx initiation, peak onset between 3-4w

27
Q

What is the onset of neutropenia/ agranulocytosis caused by abx?

A

Rapid onset of SSx, dose-related

28
Q

What is the onset of neutropenia/ agranulocytosis caused by antithyroid drugs?

What alleles could be implicated also?

A
  • More frequent in pts > 40 y/o and within 2m of Tx initiation (longer term also possible)
  • HLAB38:02 and HLADRB108:03 in ethnic Chinese
  • HLAB*27:05 white European adults
29
Q

Goals of tx of neutropenia/ agranulocytosis? (1)

A

Improving mortality rate

30
Q

Tx of neutropenia/ agranulocytosis?

How long does it take for blood cell counts to return to normal?

What should we do if neutrophil < 100 cells/mm3 (0.1 x 109/L)?

A

WITHHOLD offending drug FIRST

Blood cell counts usually return to normal within 2-4w, frequently within 4-24 days.

If neutrophil < 100 cells/mm3 (0.1 x 109/L): filgrastim (G-CSF) SQ 300mcg/day recommended

If really needed: penicillin can be restarted at LOWER dosage, AFTER neutropenia has resolved, without any recurrence of drug-induced agranulocytosis

31
Q

How is haemolytic anaemia diagnosed (what tests)?

A

Direct and indirect Coombs’ test

32
Q

What is a metabolic cause of haemolytic anaemia?

A

G6PD deficiency

33
Q

What are some unsafe medications to avoid for G6PD deficiency in haemolytic anaemia? (4)

A
  • Fluoroquinolones (-floxacin)
  • Primaquine, tafenoquine (antimalarials)
  • Sulfonylureas
34
Q

What are some chemicals and foods to avoid for G6PD deficiency in haemolytic anaemia? (3)

A
  • Fava beans
  • Henna compounds
  • Naphthalene (mothballs, lavatory deodorant)
35
Q

What are some drugs to try not to use/ use with caution for G6PD deficiency regarding haemolytic anaemia? (3)

A
  • Chloroquine, hydroxychloroquine (antimalarials)
  • Sulfamethoxazole-trimethoprim
36
Q

Define thrombocytopenia

A

Any of the following:
1. Platelet count ≤ 100,000 cells/mm3 (100 x 109/L) or greater than 50% reduction from baseline
2. Typically presents 1-2w after new drug initiated, may also present IMMEDIATELY after a dose when agent has been used intermittently in the past (hypersensitivity induction)
3. Rapid onset may occur with GPIIb/IIIa inhibitor class (eptifibatide) of drugs

37
Q

Which type of heparin causes Heparin-induced thrombocytopenia (HIT)?

A

UFH

(not LMWH!)

38
Q

Upon withholding the drug causing thrombocytopenia, how long does recovery take?

A

Recovery starts ~1-2 days of discontinuation of offending agent, and is complete at one week

39
Q

For drug-induced thrombocytopenia, should we continue the drug?

A

Advise pt to avoid the drug indefinitely as Ab may persist for years

40
Q

Regarding the “4-T’s” clinical probability score for HIT, what does each score represent?

A

Clinical probability of HIT:
6-8: High
4-5: Intermediate
0-3: Low

PR3154 (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions