To many 300 cc of 0.9% saline versus 300 cc of some dextrose containing solution is the same "volume"..... Nothing can be further from the truth. Although "volume" is a term that many use.....what it means in a patient is murky? For any volume of any type of fluid given, the effect of total intravascular volume is unknown and VERY difficult to measure....see the 3 to 1 thread. However, the following is clear...certain patients do not tolerate sodium loads well. -Cirrhotics -congestive heart failure SYNDROMES....(and i mean the syndrome not just a patient with low EF) -dialysis patients where the only avenue of sodium loss is via dialysis. All of the above patients...as part of their routine medical care are placed on sodium restricted diets....usually less than 2 grams in 24 hours...and many of those patients still require furosemide to assist in off loading the 2 grams of sodium that they take in to prevent sodium overload syndromes.....ie pulmonary edema...and edema in other parts of their bodies. sooo...in a patient with any of the above disorders....a mere 300 CC of 0.9% saline over a few hours (actually about 1 gram of sodium) WILL Cause pulmonary edema and other signs and symptoms of sodium overload states... Whereas 300cc of sodium free fluid....is really just like drinking water. And notice ...no talk of "volume" ...because in the care of these patients....Our concepts of "volume" ie...bleeding patient....is really non-applicable....and cause nephrologists and cardiologists to smile.