From the Guidelines
No, 10% glucose solution is hypertonic, not hypotonic, and 50% glucose solution is also hypertonic. Both solutions have an osmolarity higher than plasma. The 10% glucose solution has an osmolarity of approximately 505 mOsm/L, while 50% glucose solution has an osmolarity of about 2525 mOsm/L. For comparison, normal plasma osmolarity is 275-295 mOsm/L. When administered intravenously, the glucose in these solutions is rapidly metabolized, leaving free water behind. However, the initial osmotic effect of both solutions is hypertonic. This is important to understand in clinical practice because hypertonic solutions can cause vein irritation, tissue damage if extravasation occurs, and rapid fluid shifts. The study by 1 emphasizes the importance of avoiding hypotonic fluids, such as glucose solutions, for fluid resuscitation, but it does not directly address the osmotic properties of 10% and 50% glucose solutions. However, based on the known osmolarity of these solutions, it is clear that both 10% and 50% glucose solutions are hypertonic. Key points to consider in clinical practice include:
- The 50% solution is significantly more hypertonic and is typically used only in small volumes for emergency treatment of severe hypoglycemia
- 10% solutions might be used for more moderate hypoglycemia or as part of parenteral nutrition regimens
- The potential for vein irritation and tissue damage with these solutions, particularly with the 50% solution, necessitates careful administration and monitoring.
From the Research
Osmotic Properties of Dextrose Solutions
- A 10% dextrose solution is considered hypotonic, while a 50% dextrose solution is considered hypertonic 2, 3, 4.
- The osmotic properties of these solutions are relevant to their use in treating hypoglycemia, with hypertonic solutions potentially causing more rapid increases in blood glucose levels 2, 4.
Comparison of 10% and 50% Dextrose Solutions
- Studies have compared the efficacy and safety of 10% and 50% dextrose solutions in treating hypoglycemia, with some finding that 10% dextrose may be a safer and more effective alternative to 50% dextrose 2, 3, 4.
- The use of 50% dextrose solution has been associated with higher post-treatment blood glucose levels and a greater need for repeat dosing 2, 4.
Osmolality and Carbohydrate Content
- The osmolality of a solution is affected by its carbohydrate content, with higher concentrations of carbohydrates resulting in higher osmolality 5.
- Hypertonic carbohydrate-electrolyte solutions have been found to be as effective as hypotonic solutions in restoring whole-body fluid balance in situations of voluntary fluid intake 5.