From the Guidelines
An elevated RDW of 20.2 in a 92-year-old patient with a history of anemia warrants further investigation to identify the underlying cause, which may include nutritional deficiencies, early myelodysplastic syndrome, or chronic inflammation, as indicated by studies such as 1. The patient's age and history of anemia suggest that this finding could represent a worsening of an existing condition or development of a new process. According to the British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults 1, iron deficiency is common in the elderly and is often multifactorial in aetiology, and the diagnosis can be confirmed by measurement of ferritin and transferrin saturation. Key considerations in the evaluation of this patient include:
- Review of the patient's medication list for drugs that might affect erythropoiesis
- Consideration of gastroenterology consultation if occult bleeding is suspected
- Additional testing, such as a peripheral blood smear, reticulocyte count, iron studies, vitamin B12, folate levels, and possibly hemoglobin electrophoresis, to identify the underlying cause of the elevated RDW. Given the potential for iron deficiency to contribute to anemia in older adults, as noted in 1, the patient should be evaluated for iron deficiency and other potential causes of anemia, and treated accordingly to improve quality of life and prevent complications of worsening anemia. It is also important to consider the patient's overall health status and potential comorbidities when evaluating and managing their anemia, as recommended in 1.
From the Research
RDW Significance in Isolation
- The RDW value of 20.2 in a 92-year-old patient with a history of anemia may indicate a significant variation in red blood cell size, which can be associated with various underlying conditions 2.
- An increased RDW has been linked to a range of disorders, including cardiovascular disease, venous thromboembolism, cancer, diabetes, and chronic obstructive pulmonary disease, among others 2.
- In the context of anemia, an elevated RDW can suggest a nutritional deficiency, such as iron, vitamin B12, or folate deficiency, which can lead to impaired erythropoiesis and abnormal red blood cell survival 3, 2.
Clinical Implications
- The patient's age and history of anemia should be considered when interpreting the RDW value, as older adults may be more prone to nutritional deficiencies and chronic diseases that can affect red blood cell production and survival 2, 4.
- The RDW value can be used as a marker of iron deficiency, but it is not specific to this condition and can be influenced by other factors, such as inflammation, malnutrition, and excess interdialytic weight gain 4.
- Treatment of iron deficiency anemia with pharmacological iron has been shown to increase serum vitamin B12 and folate levels, highlighting the complex relationships between these nutrients and red blood cell production 5.
Differential Diagnosis
- The RDW value can be useful in differentiating between different types of anemia, such as iron deficiency anemia and thalassemia traits 6.
- A significant rise in RDW after initiation of iron therapy can help distinguish between iron deficiency anemia and other conditions, such as delta-beta thalassemia traits 6.