Anemia dilutional

Fluid retention may occur, perhaps as a result of peripheral vasodilation and/or improved insulin sensitization with a resultant increase in renal sodium and water retention. A dilutional anemia may result, which does not require treatment. Edema is reported in 4% to 5% of patients when glitazones are used alone or with other oral agents. When used in combination with insulin, the incidence of edema is about 15%. Glitazones are contraindicated in patients with New York Heart Association Class III and IV heart failure and should be used with great caution in patients with Class I or II heart failure or other underlying cardiac disease. 

A modification of the above serum folic assay method was recently described (W4). The investigators confirmed the validity of this technique as a practical means of differentiating patients with folic acid from vitamin B12 megaloblastic anemias. Another modification of this method was also described (C4). These investigators reduced the over-all sensitivity by high serum dilutions and thus made the assay, as they used it, valueless as a diagnostic tool. 

The syndrome of acute hypotension, adult respiratory distress syndrome, non-cardiogenic pulmonary edema, anemia, coagulopathy, and anaphylactic reactions after the administration of dextran 70 is referred to as the dextran syndrome (36-39). Factors other than acute volume overload due to intravascular absorption of dextran are thought to account for the syndrome. A combination of diverse pathophysiological factors may be responsible, namely direct pulmonary toxicity, activation of the coagulation cascade, release of vasoactive mediators, hypotension, pulmonary edema, intravascular intravasation of fluids, dilution of blood, and impaired renal and hepatic clearance. Cases of pulmonary edema are described under the section Respiratory. 

A single case of severe but reversible hypoplastic anemia has been attributed to sodium diatrizoate (125). Ionic contrast media have a disaggregating effect on erythrocytes, and hyperosmolar agents reduce their elasticity (SEDA-22, 501). When blood is diluted with 90% sodium diatrizoate in vitro, there is initially a reduction in... 

As many as 10% of patients show signs of salt and fluid retention and edema (7). Increased intravascular fluid volume is responsible for dilution anemia and increasing cardiac load (SED-8, 216). There is still no explanation for the water-retaining effect, but it might reflect increased production of antidiuretic hormone. 

Equations for calculating the appropriate dose of parenteral iron in patients with IDA or those with anemia secondary to blood loss can be found in Table 99-7. When given by IV administration, the dose should not exceed 50 mg of iron per minute (1 mL/min). It is suggested that all patients considered for an iron dextran injection receive a test dose of 25 mg IM or IV, or a 5- to 10-minute infusion of the diluted solution. Patients should then be observed for more than 1 hour for untoward reactions. If an anaphylaxis-like reaction were to occur, it generally responds to IV epinephrine, diphenhydramine, and corticosteroids. Patients receiving total dose infusions can have the remaining solution infused during the next 2 to 6 hours if the test dose is tolerated. 

Children. Give 0.15-0.33 mL/kg to a maximum of 10 mL. Pediatric dosing should be based on the hemoglobin concentration, if known (see Table 111-10). If anemia is suspected or hypotension is present, start with the lower dose, dilute in 50-100 mL of saline, and give over at least 5 minutes. 

Marrow from patients with megaloblastic anemia in relapse has been cultured by Lajtha s modification of Osgood and Brownlee s method (Lajtha, 1952). Lajtha (1950), Thompson (1950), and Cox (1953) used this technique to demonstrate an inhibitory factor in pernicious anemia serum. Diluting pernicious anemia serum with a physiological salt solution increased its maturing effect on megaloblasts in culture. This fact cannot be explained on a deficiency basis. 

Diluting normal serum reduces its maturing effect. Lajtha (1950) demonstrated that when a marrow with a normoblastic erythropoiesis is cultured for 72 hours in pernicious anemia serum, megaloblasts may appear. This led him to conclude that the megaloblast is a pathological variant of a normoblast and that both states are reversible. 

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