Why is isotonic saline rather then pure water administrated by intravenous drip to patients who are dehydrated

Answer 1

Pure water is never given IV. It could be disastrous. It would be hypotonic. Red blood cells lysis would occur due to the osmotic gradient. A large volume of pure water IV would play havoc with blood osmolarity. That's why 5% dextrose is given if one does not wish to give saline solutions.
MD answer

Answer 2

Water moves down its concentration gradient and because of the electrolytes that are dissolved inside cells, an infusion of pure water would shift A LOT of water into cells, most importantly into red blood cells. This would cause the cells to swell and burst. Ruptured cells don't work very well....This is why doctors use normal saline and not water in IV drips

Answer 3

the fluid administered through IV drip mixes with the extra cellular fluid (ECF)of our body.the main electrolytes present in the ECF are sodium and chloride. due to dehydration even these electrolytes are lost along with the fluid. pure water does not contain these electrolytes. saline is made upof sodium chloride and water. it is called isotonic because the concentration of sodium chloride in it equals to the concentration of sodium chloride in the blood.therefore isotonic saline is administered to correct electrolyte imbalance along with dehydration.

Answer 4

isotonic solution along with glucose is admistered coz it is important to maintain the pH of blood and body fluids... if u gonna give water which is neutral will change the ph and ll result in cell lysis