COVID-19-associated anemia
For COVID-19 frequently asked inpatient questions, click here
For COVID-19 frequently asked outpatient questions, click here
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Shakiba Hassanzadeh, MD[2]
Synonyms and keywords: Hemoglobin changes in COVID 19, anemia in COVID 19, effects on erythropoiesis in COVID 19
Overview
Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus called SARS-CoV-2, which caused a respiratory illness outbreak that was first detected in Wuhan, China. Anemia in general is defined as a hemoglobin level of less than 13 gm/dL in men and less than 12 gm/dL in women by the World Health Organization (WHO). Although anemia is not a common finding in patients with COVID-19 infection, decrease in hemoglobin in patients with severe COVID-19 infection has been reported. The pathophysiology of decrease in hemoglobin in patients with COVID-19 infection are hypothetically affected erythropoiesis due to inflammation during COVID-19 infection which leads to decrease in hemoglobin.
Historical Perspective
- Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus called SARS-CoV-2, which caused a respiratory illness outbreak that was first detected in Wuhan, China.[1][2]
- On January 30, 2020, the outbreak was declared a Public Health Emergency of International Concern.
- On March 12, 2020, the COVID-19 outbreak was declared a pandemic by the World Health Organization (WHO).
Classification
- Anemia, in general, is defined as a hemoglobin level of less than 13 g/dL in men and less than 12 g/dL in women by the World Health Organization (WHO).
- The following is the classification of anemia in general by red blood cell size with mean corpuscular volume (MCV):
- Macrocytic anemia (MCV>100)
- Normocytic anemia (80<MCV<100)
- High reticulocyte count
- Low reticulocyte count
- Microcytic anemia (MCV<80)
Here is a schematic representation of how to consider anemia with MCV as the starting point:
Other characteristics visible on the peripheral smear may provide valuable clues about a more specific diagnosis; for example, abnormal white blood cells may point to a cause in the bone marrow.
Pathophysiology
The pathophysiology of decrease in hemoglobin and rarity of anemia in patients with COVID-19 infection are as the followings:[3]
- Erythropoiesis may be affected by inflammation during COVID-19 infection which leads to decrease in hemoglobin.[3]
- Anemia is not a common finding probably due to the compensation of erythrocyte proliferation caused by pneumonia-induced hypoxia and the long life span of erythrocytes.[3]
Causes
- Coronavirus disease 2019 (COVID-19) caused by a novel coronavirus called SARS-CoV-2 is the cause of COVID-19-associated-anemia.
Differentiating COVID-19-associated Anemia from other Diseases
Differential diagnosis of anemia in general may include:[4]
- Iron deficiency anemia
- Thalassemia
- Sideroblastic anemia
- Anemia of inflammation
- Aplastic anemia
- Hypothyroidism
- Liver disease
- Renal disease
- Reticulocytosis
- Thyroid disease
- Vitamin B12 and folate deficiency
- Chemotherapy
- Myelodysplastic syndrome
- Acute onset hemolysis or blood loss
For complete differential diagnosis of anemia please click here.
Epidemiology and Demographics
- Anemia is a very rare complication of COVID-19.[3]
- There is no new update about COVID-19 associated anemia.
Risk Factors
- There is no associated risk factor for COVID-19 associated anemia.
Screening
Natural History, Complications, and Prognosis
- Although anemia is not a common finding in patients with COVID-19 infection, but decrease in hemoglobin in patients with severe COVID-19 infection has been reported.[3][5]
- The median hemoglobin is lower in patients with severe COVID-19 (12.8 gm/dL) compared to patients with non-severe infection (13.5 gm/dL).[5]
- Decrease in hemoglobin is seen more in critically ill patients with severe COVID-19 infection.[5]
Diagnosis
Diagnostic Study of Choice
- The diagnostic study of choice for anemia is compelete blood count (CBC).
- Anemia, in general, is defined as a hemoglobin level of less than 13 g/dL in men and less than 12 g/dL in women by the World Health Organization (WHO).
- The median hemoglobin is lower in patients with severe COVID-19 (12.8 g/dL) compared to patients with non-severe infection (13.5 g/dL).[5]
History and Symptoms
- There is insufficient information about the symptoms of COVID-19-associated-anemia.
- Patients with anemia in general should be asked about:[6]
- Blood loss
- Duration of the anemia
- Any associated features
- Infection
- Cancer
- Comorbidities that cause anemia (such as renal failure, rheumatoid arthritis, and inflammatory bowel disease)
- Past medical history
- Patient’s ethnicity may influence the differential
- Family history
- Drug history (aspirin and NSAIDs)
Physical Examination
- There is insufficient information about the signs found on physical examination of COVID-19-associated-anemia.
- The physical examination in patients with anemia in general may include checking for:[6]
- Pallor of the conjunctiva
- Lymphadenopathy
- Hepatosplenomegaly
- Bone tenderness
- Petechiae
- Ecchymose
Laboratory Findings
- Compelete blood count (CBC):[4][5]
- The median hemoglobin is lower in patients with severe COVID-19 (12.8 g/dL) compared to patients with non-severe infection (13.5 g/dL).
- Peripheral blood smear: Maybe helpful if there is a suspicion of other causes of anemia. However, there is insufficient evidence recommending routine peripheral blood smear in COVID 19 patients.
- Reticulocyte count: May be helpful if there is a suspicion of other causes of anemia.
- Red cell indices: May be helpful if there is a suspicion of other causes of anemia.
- To view the laboratory findings on COVID-19, click here.
Electrocardiogram
- There are no ECG findings associated with COVID-19-associated anemia.
- However, the following findings may be seen on ECG in patients with anemia: tachycardia, ST depression, T wave changes (T wave flattening and inversion), and QRS abnormalities (indicating LVH and cardiac enlargement).[7]
- To view the electrocardiogram findings on COVID-19, click here.
X-ray
- There are no x-ray findings associated with COVID-19 associated anemia.
- To view X-ray findings of COVID-19 ,click here.
Echocardiography or Ultrasound
- There are no echocardiography/ultrasound findings associated with COVID-19-associated anemia.
- To view the echocardiographic findings on COVID-19, click here.
CT scan
- There are no CT scan findings associated with COVID-19 associated-anemia.
- To view the CT scan findings on COVID-19, click here.
MRI
- There are no MRI findings associated with COVID-19 associated-anemia.
- To view the MRI findings on COVID-19, click here.
Other Imaging Findings
- There are no other imaging findings associated with COVID-19 associated-anemia.
- To view other imaging findings on COVID-19, click here.
Other Diagnostic Studies
- Bone marrow examination: May be helpful if there is a suspicion of other causes of anemia.[4] However, there is insufficient evidence recommending routine bone marrow examination in COVID-19 patients
- Cytogenetic and molecular tests : May be helpful if there is a suspicion of other causes of anemia. However, there is insufficient evidence recommending routine cytogenetic and molecular in COVID-19 patients.
- To view other diagnostic studies for COVID-19, click here.
Treatment
Medical Therapy
- Treatment of anemia in general depends on the cause of anemia.[6]
- No specific treatment has been reported for COVID-19-associated-anemia.
Surgery
Primary Prevention
Secondary Prevention
- Minimal amount of blood should be drawn for blood tests and only clinically necessary tests should be ordered in order to prevent aggregation of COVID-19 associated anemia.[8]
References
- ↑ https://www.cdc.gov/coronavirus/2019-ncov/about/index.html. Missing or empty
|title=(help) - ↑ Lu, Jian; Cui, Jie; Qian, Zhaohui; Wang, Yirong; Zhang, Hong; Duan, Yuange; Wu, Xinkai; Yao, Xinmin; Song, Yuhe; Li, Xiang; Wu, Changcheng; Tang, Xiaolu (2020). "On the origin and continuing evolution of SARS-CoV-2". National Science Review. doi:10.1093/nsr/nwaa036. ISSN 2095-5138.
- ↑ 3.0 3.1 3.2 3.3 3.4 Liu X, Zhang R, He G (2020). "Hematological findings in coronavirus disease 2019: indications of progression of disease". Ann Hematol. doi:10.1007/s00277-020-04103-5. PMC 7266734 Check
|pmc=value (help). PMID 32495027 Check|pmid=value (help). - ↑ 4.0 4.1 4.2 Cascio MJ, DeLoughery TG (2017). "Anemia: Evaluation and Diagnostic Tests". Med Clin North Am. 101 (2): 263–284. doi:10.1016/j.mcna.2016.09.003. PMID 28189170.
- ↑ 5.0 5.1 5.2 5.3 5.4 Guan WJ, Ni ZY, Hu Y, Liang WH, Ou CQ, He JX; et al. (2020). "Clinical Characteristics of Coronavirus Disease 2019 in China". N Engl J Med. 382 (18): 1708–1720. doi:10.1056/NEJMoa2002032. PMC 7092819 Check
|pmc=value (help). PMID 32109013 Check|pmid=value (help). - ↑ 6.0 6.1 6.2 Powell DJ, Achebe MO (2016). "Anemia for the Primary Care Physician". Prim Care. 43 (4): 527–542. doi:10.1016/j.pop.2016.07.006. PMID 27866575.
- ↑ Gv S, Pk S, Herur A, Chinagudi S, Patil SS, Ankad RB; et al. (2014). "Correlation Between Haemoglobin Level and Electrocardiographic (ECG) Findings in Anaemia: A Cross-Sectional Study". J Clin Diagn Res. 8 (4): BC04–6. doi:10.7860/JCDR/2014/8966.4202. PMC 4064835. PMID 24959433.
- ↑ Baron DM, Franchini M, Goobie SM, Javidroozi M, Klein AA, Lasocki S; et al. (2020). "Patient blood management during the COVID-19 pandemic: a narrative review". Anaesthesia. doi:10.1111/anae.15095. PMID 32339260 Check
|pmid=value (help).