In this article, we will discuss two types of normocytic anemia: Anemia in Chronic Kidney Disease and Hemorrhagic Anemia.
Introduction to Normocytic Anemia
To determine whether it is microcytic, normocytic, or macrocytic anemia, we look at the mean corpuscular volume (MCV). If the MCV is less than 80, then it is considered microcytic anemia. If it’s between 80-100, then it is normocytic anemia. And if it is more than 100, it is macrocytic anemia.
The two types of normocytic anemia that will be discussed in this article are anemia in chronic kidney disease and hemorrhagic anemia.
Other types of normocytic anemia are sickle cell anemia and aplastic anemia, which will be discussed in a future article.
Anemia in Chronic Kidney Disease (CKD)
Our kidney is responsible for initiating the production of erythropoietin. A damaged kidney leads to a decreased production of erythropoietin. Additionally, red blood cells produced in CKD patients have a shorter lifespan.
Treatment of CKD Anemia
There are several different considerations when choosing the treatment. Some of these considerations are curative vs. palliative goals in patients with cancer, iron storage, and the severity of anemia.
The goal of the treatment is to replenish red blood cells. There are several ways to achieve this, but many of these processes take a while. For example, ESA can take up to 10 days for the onset. If the patient is actively bleeding or needs immediate replenishment, a blood transfusion is an ideal option.
Why It Is Important to Address Iron
Iron is an essential part of erythropoiesis. If there is an iron deficiency, the production of red blood cells is limited. The KDIGO guidelines recommend iron repletion treatment if serum transferrin saturation (TSAT) is less than 30% and ferritin is less than <500 mcg/L or if an increase in hemoglobin concentration without starting ESAs is desired. IV or oral formulation are both acceptable except in patients on hemodialysis. In this patient population, only IV iron is recommended.
Erythropoietin Stimulating Agents (ESAs)
ESAs give the body something it can produce red blood cells with. The use of ESAs has been associated with fewer transfusions and anemia-related symptoms, but also comes with an increased risk of cardiovascular events and hypertension.
ESAs are recommended in
- CKD stage 5 (GFR <15) – only between hemoglobin between 9 and 10. This is due because the use outside this range has been associated with an increased risk of cardiovascular events.
- Palliative cancer patients – ESAs should only be used in palliative cancer patients and not curative cancer patients due to the increased risk of cardiovascular events and shortened overall survival.
- Patients who refuse blood transfusions.
Epoeitin alfa – this is the more common of the two ESAs available. It is indicated for anemia due to chemotherapy, CKD, zidovudine, myelodysplastic syndromes (off-label), and RBC transfusion refusal. There is a biosimilar agent called Retacrit. The dosing is three times weekly in cancer and CKD patients on hemodialysis and every 1-2 weeks for CKD patients not on hemodialysis.
Darbepotein – this is indicated for anemia due to chemotherapy, CKD, and myelodysplastic syndromes (off-label). It is dosed weekly for cancer patients and CKD patients on hemodialysis.
ESAs have a BBW for increased risk of MI, stroke, VTE, and death.
Other ADRs: Hypertension, arthralgia, edema, headache, and dyspnea.
The dosing is based on patient response and goal, which is usually to reduce transfusion numbers. The dose should be held if
- There is a rapid increase in hemoglobin (more than 1 within 2 weeks)
- Hemoglobin nearing 11 in hemodialysis patients.
- Hemoglobin nearing 10 in CKD non-HD patients.
The onset, as mentioned before, is within 10 days with a peak in 2-6 weeks.
The therapy should be discontinued if there is no reduction in the number of transfusion requirements or any rise in hemoglobin (less than 1-2) within 6-8 weeks.
Hemorrhagic Anemia
The most common cause of hemorrhagic anemia is blood loss through trauma, GI bleeding, surgery, and heavy menstruation.
This anemia requires rapid correction of hemoglobin.
If the patient is on an anticoagulant, a reversal agent, such as Vitamin K or Kcentra, should be used.
If the patient is losing blood quickly and the wound is not closing, cauterization may be needed.
Blood transfusion should be considered in patients with hemoglobin less than 7 because patients can typically compensate for up to hemoglobin 8.