Talk:Intravenous fluids
From Ganfyd
Osmolality and tonicity
Explain to me why a hyperosmolar solution can be hypotonic?? The exertion of osmotic pressure relies only on the number of particles (ions or molecules) of solute in the solvent. So if the osmolality of 5% dextrose with 20mM KCl is 317 (given as the example), this is a hypertonic solution. There is a difference between osmolarity and osmolality, but this doesn't seem to be saying that.Preacherdoc 23:21, 9 March 2007 (UTC)
- Have changed the explanation to make it a bit clearer and also referred to the tonicity page with a more detailed explanation. Mark ong 01:13, 10 March 2007 (UTC)
- Thanks for that. Your explanation and rewording are fine. However, I still don't like the statement that tonicity and osmolality are independent, and the current wording suggests that they are. In fact, tonicity refers to relative concentration, and osmolality refers to absolute concentration: they are inextricable.Preacherdoc 03:39, 10 March 2007 (UTC)
- Tremendous rewrite Mark- this is much clearer.Preacherdoc 21:20, 10 March 2007 (UTC)
- Thanks for that. Your explanation and rewording are fine. However, I still don't like the statement that tonicity and osmolality are independent, and the current wording suggests that they are. In fact, tonicity refers to relative concentration, and osmolality refers to absolute concentration: they are inextricable.Preacherdoc 03:39, 10 March 2007 (UTC)
