Chapter 49: Hematologic & Immunologic Dysfunction Anemia: Because the viscosity of blood depends almost entirely on the concentration of RBCs the resulting hemodilution of severe anemia ↓ peripheral resistance, causing greater quantities of blood return to the heart. Anemia = ↓ RBCs &/or ↓ Hgb. Hgb @ 2 months = 9 – 14 Hgb @ 6 – 12 years = 11.5 – 15.5 Iron deficient anemia occurs more commonly in infants between 6 & 24 months & during growth spurt of adolescence. The statement ‘the baby drinks a lot of milk’ is a common finding in infants c iron deficiency anemia. Bone marrow aspiration is not a routine hematologic test but is essential for definitive D x of the leukemias, lymphomas & certain anemias. Iron Deficiency Anemia: This type of anemia is the most prevalent nutritional disorder in the US & the most common mineral disturbance. During the 1 st trimester of pregnancy, iron is transferred from mother to fetus. Most of the iron is stored in the circulating erythrocytes of the fetus, c the remainder stored in the fetal liver, spleen & bone marrow. These iron stores are usually adequate for the 1 st 5 – 6 months in a full-term infant but for only 2 – 3 months in a premature infant or multiple births. Although most infants c iron deficiency anemia are underweight, many are overweight because of excessive milk ingestion (milk babies). These children become anemic for 2 reasons: milk, a poor source of iron, is given almost to the exclusion of solid foods & some infants fed cow’s milk have an ↑ fecal loss of blood. To ↓ the possibility of iron deficiency from GI blood loss occurring from allergy to the milk protein, infants ↓ 12 months of age should not be given fresh cow’s milk. Dietary addition of iron-rich foods is usually inadequate as the sole T x of iron deficiency anemia because the iron is poorly absorbed & provides insufficient supplemental quantities of iron. If dietary sources of iron cannot replace body stores, oral iron supplements are prescribed for approx 3 months. Ferrous iron, more readily absorbed than ferric iron, results in↑ Hgb levels. Ascorbic acid facilitates absorption. If the Hgb level is very low or if levels fail to rise after 1 month of oral T x , it is important to assess whether the iron is being administered correctly. Transfusions are indicated for the most severe anemia & in cases of serious infection, cardiac dysfunction, or surgical emergency when anesthesia is required. Packed RBCs (2 – 3 cc/kg), not whole blood, are used to minimize the chance of circulatory overload. o Nursing care mgmt: Oral iron should be given as prescribed in 2 divided doses between meals, when the presence of free hydrochloric acid is greatest, because more iron is absorbed in the acidic environment of the upper GI tract.
- Spring '09
- David Gauthier
- Hematology, Hemoglobin, Bone marrow