2155 (IC14) anaemia Flashcards
What is erythropoietin?
Glycoprotein cytokine produced by kidneys in response to tissue hypoxia
Function of erythropoietin
Stimulate erythropoiesis in bone marrow → Increase RBC production
Bind to EPO receptors → activate progenitor cells to differentiate and proliferate to mature RBC
2 strategies to improve half life and stability of epoietin
- Add more N linked groups (Darbepoietin VS Epoietin Alfa and Beta)
- PEGylation, adding Polyethylene Glycol to epoietin
Why do CKD patients have decreased RBC production? (4 points)
- From decreased production of Erythropoietin by kidney
- Accumulation of uremic toxins → Inhibit erythropoiesis
- Bone marrow fibrosis caused by hyperparathyroidism (elevated thyroid hormone PTH from CKD mineral bone disease)
- CKD patients have nutritional deficiencies
Normal and anemic levels of Haemoglobin for male and females
Male
Normal: 13-15g/dL, Anaemia: < 13
Female
Normal: 12-14g/dL, Anaemia: < 12
Consequences and Complications of anemia
Decreased O2 delivery to other organs can result in LVH, MI, stroke
Target for Hgb, should not exceed how much?
10-11.5g/dL, should not exceed 13
Goal TSAT
20-30%
Goal Serum Ferritin
200-500 for HD patients, 100-100 for non-HD patients
What is TSAT
Transferrin Saturation, measure amount of iron available for delivery to bone marrow
What is TSAT equation?
Serum Iron/TIBC x 100%
What is serum ferritin?
Indirect measure of iron stores, is an acute phase reactant
When to start ESA?
Start ESA when Hbg < 10g/dL
Dose titration of ESA? eg. too fast, too slow, Hgb approaching 12, exceed 13?
Hgb should increase 1-2g/dL per month
If Hgb increase < 1g/dL over 4 weeks (too slow), increase frequency
If Hgb increase > 1g/dL over 2 weeks (too fast), increase dosing interval
If Hgb approaching 12, increase ESA dosing interval
If Hgb > 13g/dL, hold EPO until Hgb < 12-12.5, then restart at longer frequency
Too high Hgb → blood is thicker, greater risk of clots
Dose adjust every 2-4 weeks
Causes of hyporesponsiveness to ESAs
Iron deficiency / Folate, B12 deficiency
All these needed to make RBC
Hyperparathyroidism
Aluminium toxicity
and many more…
Why does iron deficiency occur in CKD patients? (2 points)
1) Malnutrition
2) ESA treatment increases iron demand
What are the 2 types of iron deficiency?
Absolute → Low TSAT, Low Ferritin
AKA low iron freely available, low iron stores
Functional → Low TSAT, high Ferritin
AKA low iron freely available, high iron stores
Alot of iron stores not cannot release fast enough to meet demands
May also be due to inflammation causing increase in Ferritin, hence not accurate
What are the 2 types of oral iron? What are their relative iron elemental %?
Ferrous gluconate (Sangobion): 12% elemental iron
Iron polymaltose (Maltofer): 100% elemental iron
How much iron do non HD patients need?
200mg
What is IV iron called and the brand name?
Iron Sucrose (Venofer)
What is the dosing of Iron Sucrose?
During each HD session, give Loading dose of 100mg x 10 doses or 200mg x 5 doses = 1g per month
Maintenance dose
100-200mg IV per month
Side effects of IV iron
Hypotension, dizziness, dyspnea, syncope, arthritis, back pain, joint pain
Anaphylactoid reaction
Iron overload
Cause hepatic, pancreatic, cardiac dysfunction
Increase risk of infection
Withhold IV iron during acute infection or switch to oral iron
Oxidative stress
When is transfusion appropriate?
For patients with acute blood loss and severe symptomatic anaemia
Symptoms eg. pale, short of breath
Risks during transfusion
Impair bone marrow RBC synthesis
Volume overload
Iron overload
Infection eg. hepatitis, HIV
Who should avoid doing transfusion?
Avoid transfusion for patients who are candidates for kidney transplant!
Risk immune reaction against blood
Eventually, body might reject kidney
Give higher doses of ESAs, not transfusion
DO not start ESAs when patient has
(absolute) active cancer and patient is receiving treatment with curative intent
(relative) history of stroke
history of malignancy
