Low Molecular Weight Dextran 40 (Dextran 40) is a hyperoncotic plasma volume expander derived from the polysaccharide dextran, with an average molecular weight of approximately 40,000 Daltons. It is a sterile, pyrogen-free solution in either normal saline (NS) or dextrose (D5W). In the Indian clinical context, it is primarily used for its rheological properties to improve microcirculatory flow and as a short-term plasma volume expander in hypovolemic shock, before blood or other colloids are available. It is not a substitute for blood or blood products.
Adult: Initial: 500-1000 mL infused IV rapidly. Maintenance: Total daily dose should not exceed 20 mL/kg (approx. 1.5 L for a 75 kg adult). For shock: 500 mL infused as fast as possible (10-15 mL/min), repeated based on response. For thrombosis prophylaxis: 500-1000 mL daily during the period of risk, infused over 4-6 hours.
Note: For IV infusion only. Use a sterile, non-pyrogenic infusion set. Must be administered through a large-bore IV catheter. Do not mix with blood for transfusion in the same line; it can cause pseudoagglutination. The initial 20-30 mL should be infused slowly while monitoring for anaphylactoid reactions. Compatible with Normal Saline and Dextrose 5% solutions.
Dextran 40 exerts its effects through two primary mechanisms: 1) Plasma Volume Expansion: It creates a hyperoncotic solution that draws interstitial fluid into the intravascular compartment, thereby increasing plasma volume. The effect is greater than the volume infused but is transient due to rapid renal excretion. 2) Rheological Effect: It reduces blood viscosity by decreasing red blood cell aggregation, disaggregating existing rouleaux formations, and improving erythrocyte flexibility. This enhances microcirculatory blood flow, particularly in low-flow states.
Pregnancy: Category C: Animal reproduction studies have not been conducted. Should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Use restricted to life-threatening hypovolemic situations.
Driving: No effect. However, underlying condition (e.g., post-surgery, shock) would be the limiting factor.
| Aminoglycosides (e.g., Gentamicin) | Increased risk of nephrotoxicity (additive renal tubular damage). | Major |
| Anticoagulants (Warfarin, Heparin) & Antiplatelets (Aspirin, Clopidogrel) | Potentiated anticoagulant effect; increased risk of bleeding. | Major |
| ACE Inhibitors (e.g., Enalapril) | Increased risk of anaphylactoid reactions. | Moderate |
| Insulin | Dextran metabolism yields glucose; may affect glycemic control. Interference with some blood glucose monitoring systems. | Moderate |
Same composition (Low Dextrans ( 50000 Daltons) (NA)), different brands: