Intravenous Fluids and Plasma Expanders

Key points

• • Intravenous fluids replace lost water, salts and volume, and are broadly divided into crystalloids and colloids.
• • Crystalloids such as normal saline and Ringer's solution contain salts and water and spread through the body's fluid spaces.
• • Colloids and plasma expanders contain larger molecules that tend to stay in the vessels longer, though crystalloids are commonly preferred and colloids carry their own risks.
• • Dextrose solutions provide water and a little energy, and are used to correct a pure loss of water.
• • Giving too much fluid can overload the circulation and flood the lungs, so the type and amount are matched to the need.