From the Guidelines
Yes, illness can cause a significant decrease in hemoglobin levels, as evidenced by the high prevalence of anemia in critical care patients, affecting about two thirds of patients on admission, with a mean haemoglobin level of 11.0 g/dL 1. Many diseases and conditions can lead to reduced hemoglobin, including infections, chronic inflammatory disorders, kidney disease, cancer, and nutritional deficiencies. During infection or inflammation, the body produces cytokines that can suppress red blood cell production in the bone marrow and reduce the lifespan of existing red blood cells. Chronic kidney disease impairs the production of erythropoietin, a hormone essential for red blood cell formation. Certain cancers, particularly those affecting bone marrow, can directly interfere with blood cell production. Gastrointestinal conditions may cause bleeding or impair nutrient absorption, especially iron, vitamin B12, and folate, which are crucial for hemoglobin synthesis. Additionally, some medications used to treat illnesses can suppress bone marrow function as a side effect. The severity of hemoglobin reduction depends on the underlying condition, its duration, and individual factors. Treatment typically focuses on addressing the underlying illness while sometimes supplementing with iron, vitamins, or in severe cases, blood transfusions or erythropoiesis-stimulating agents, with the recommendation that RBC transfusion occur only when hemoglobin concentration decreases to < 7.0 g/dL in adults in the absence of extenuating circumstances 1.
Some key points to consider include:
- The high prevalence of anemia in critical care patients, with about two thirds of patients being affected on admission 1
- The association between the severity of anemia on admission and increased morbidity and mortality in critical care patients 1
- The recommendation to use a restrictive transfusion strategy, with RBC transfusion occurring only when hemoglobin concentration decreases to < 7.0 g/dL in adults in the absence of extenuating circumstances 1
- The importance of addressing the underlying illness and sometimes supplementing with iron, vitamins, or in severe cases, blood transfusions or erythropoiesis-stimulating agents.
Overall, illness can have a significant impact on hemoglobin levels, and treatment should focus on addressing the underlying condition and managing anemia accordingly, with a restrictive transfusion strategy and careful consideration of individual patient factors 1.
From the Research
Illness and Hemoglobin Levels
- Illness can cause a decrease in hemoglobin levels, as evident from studies on anemia in chronic diseases such as rheumatoid arthritis and chronic kidney disease 2, 3, 4, 5, 6.
- Anemia is a common complication of chronic diseases, and it can lead to a reduction in hemoglobin concentration, which can further exacerbate the disease 2, 3.
- The pathophysiology of anemia in chronic diseases involves a disordered process in which the rate of red cell production fails to match the rate of destruction, leading to a reduction in hemoglobin concentration 2.
Types of Anemia
- There are different types of anemia, including iron-deficiency anemia (IDA) and anemia of chronic disease (ACD) 4, 6.
- IDA is caused by a lack of iron, while ACD is caused by chronic inflammation and can lead to a reduction in hemoglobin levels 4, 6.
- Some studies suggest that ACD is more common in patients with rheumatoid arthritis, while others suggest that IDA is also prevalent in these patients 4, 6.
Diagnosis and Management
- Diagnosing the type of anemia is crucial for effective management, as different types of anemia require different treatments 3, 4.
- Serum transferrin receptor-ferritin index can be used to distinguish between IDA and ACD, and to identify patients with coexistent IDA and ACD 6.
- Management of anemia in chronic diseases requires a multidisciplinary approach, including the use of iron therapy, erythropoiesis-stimulating agents, and blood transfusions 2, 3.