What Is Renal Anemia?

Renal anemia is caused by impaired renal function, especially when the glomerular filtration rate is lower than 30 ml / min or the serum creatinine (SCr) concentration is higher than 300 mol / L and the hemoglobin is reduced. anemia. This disease is a common complication of chronic kidney disease (CKD) and an independent risk factor for cardiovascular complications in patients with chronic kidney disease.

Basic Information

Visiting department: Nephrology
Common causes: Reduced erythropoietin production

Common symptoms: Chills, fatigue, lethargy, lack of appetite, muscle weakness, decreased mobility, decreased memory and intelligence, shortness of breath at rest or activity, palpitations, etc.

Causes of renal anemia

The main cause of renal anemia is reduced production of erythropoietin (EPO). The patient's chronic kidney disease continued to develop, and the residual renal function decreased. On the one hand, the erythropoietin production was reduced, and on the other hand, the residual kidney was unable to respond adequately to the hypoxic stimulation caused by anemia. And uremic toxins and erythropoiesis inhibitors can cause patients to reduce responsiveness to erythropoietin; uremic toxins can affect the bone marrow microenvironment, patients with malnutrition may have iron and folic acid deficiency; patients with potential bleeding factors may have Blood loss; shortened red blood cell life and hemolysis. In addition, secondary hyperparathyroidism, aluminum poisoning, etc. can also cause and exacerbate renal anemia.

Clinical manifestations of renal anemia

Patients with chronic renal anemia may have non-specific symptoms of various systems such as chills, fatigue, lethargy, lack of appetite, muscle weakness, decreased mobility, difficulty in concentration, decreased memory and intelligence, shortness of breath at rest or activity, palpitations, Angina pectoris and decreased libido. Physical examination patients may have anemia, rapid breathing, and tachycardia.

Renal anemia test

1. Laboratory examination (1) Blood routine examination: Reticulocyte count decreased, but it was not proportional to the degree of anemia. Hematocrit decreases, red blood cell count decreases, and hemoglobin (Hb) decreases.
(2) Peripheral blood smear: occasionally broken red blood cells, mostly normal.
(3) Renal function test: serum creatinine increases, and endogenous creatinine clearance (CCr) decreases.
(4) Examination of iron metabolism: decreased serum ferritin (<12 g / L), decreased serum iron (<8.95 mol / L), decreased transferrin saturation (<15%), suggesting iron deficiency.
2. EEG showed impaired cognitive function in patients.

Renal anemia diagnosis

Anemia is diagnosed in Chinese adult men with hemoglobin <120g / L, non-pregnant women <110g / L, and pregnant women <100g / L. Such as glomerular filtration rate min or serum creatinine> 300mol / L should be considered anemia caused by renal failure, but anemia caused by other reasons should be ruled out.

Differential diagnosis of renal anemia

Renal anemia needs to be distinguished from anemia caused by other causes. If the degree of anemia is not proportional to the degree of kidney damage, other causes should be considered. Blood smears, serum erythropoietin, serum iron, and serum transferrin saturation tests can assist identification. If the level of erythropoietin is elevated, there is almost certainly anemia caused by other causes. It should be noted that renal anemia may be combined with other types of anemia (such as iron deficiency anemia).

Renal anemia treatment

The treatment of renal anemia mainly includes three aspects.
1. Supplementation of red blood cell stimulating agent (ESA)
Erythropoiesis stimulating agents include rHuEPO, daepoetin-, and the like. Treatment of erythropoiesis stimulants should pay attention to the hemoglobin level and target value when starting treatment. When hemoglobin L, erythropoiesis stimulus treatment should be started. The target value for women is> 110g / L and for men is> 120g / L, but it should not exceed 130g / L to avoid increasing the risk of high-risk adverse events.
2. Iron Supplementation Almost all renal anemias require iron supplementation. Iron supplementation should be checked by serum ferritin and serum transferrin saturation to determine whether the patient has iron deficiency and the degree of iron deficiency, and to determine the route and dose of iron supplementation. In the course of treatment, care should be taken to evaluate the effect of iron supplementation in order to prevent If the treatment is unsatisfactory or the iron load is excessive, those who are not satisfied with the curative effect should pay attention to check whether there are other factors that cause iron absorption or utilization obstacles.
3. Correct the factors that affect the treatment or promote anemia in patients with poor erythropoiesis stimulants. In addition to paying attention to whether there is insufficient dose of erythropoiesis stimulant or iron deficiency, there should be attention to whether there are other factors that affect the treatment, such as inflammation and infection. , Chronic blood loss, aluminum poisoning, folic acid and vitamin B12 deficiency, anti-erythropoietin antibodies in the body, secondary hyperparathyroidism, hemoglobinopathy, multiple myeloma, severe malnutrition, etc. If the erythropoiesis-stimulating agent is ineffective and cannot be corrected in time, the patient can only receive blood transfusion therapy.

Prognosis of renal anemia

If renal anemia is not treated in time, it can lead to death due to severe anemia-induced angina pectoris and heart failure. Children can cause growth retardation and mental decline, reduce the survival rate of patients, and affect the rehabilitation and quality of life of patients. Anemia can be corrected to the target value through timely treatment.

Renal anemia prevention

Patients with chronic kidney disease can know whether there is anemia through regular anemia-related inspections such as blood routine, blood smears, serum ferritin and serum transferrin saturation, etc. At the same time, they should actively treat chronic kidney disease, pay attention to supplemental nutrition, and avoid infection. Factors that may induce anemia.