
Health Dictionary
Reliable, easy-to-read patient information on common medical conditions — written in plain language, free of jargon, and grounded in current evidence. Browse the most frequent diagnoses, understand what they mean for everyday life, and learn which steps and questions help you have a focused conversation with your doctor.
Intravenous fluid
Introduction
Intravenous Fluid
There are two types of fluids that are used for intravenous drips; crystalloids and colloids. Crystalloids are aqueous solutions of mineral salts or other water-soluble molecules. Colloids contain larger insoluble molecules, such as gelatin; blood itself is a colloid.
The most commonly used crystalloid fluid is normal saline, a solution of sodium chloride at 0.9% concentration, which is close to the concentration in the blood (isotonic). Ringer’s lactate or Ringer’s acetate (ASERING, patented brandname of Otsuka Indonesia) is another isotonic solution often used for large-volume fluid replacement. A solution of 5% dextrose in water, sometimes called D5W, is often used instead if the patient is at risk for having low blood sugar or high sodium. The choice of fluids may also depend on the chemical properties of the medications being given.
Intravenous fluids must always be sterile.
Crystalloid Fluids
| Solution | Other Name | [Na+](mmol/L) | [Cl–](mmol/L) | [Glucose](mmol/L) | [Glucose](mg/dl) |
|---|---|---|---|---|---|
| D5W | 5% Dextrose | 0 | 0 | 278 | 5000 |
| 2/3D & 1/3S | 3.3% Dextrose / 0.3% saline | 51 | 51 | 185 | 3333 |
| Half-normal saline | 0.45% NaCl | 77 | 77 | 0 | 0 |
| Normal saline | 0.9% NaCl | 154 | 154 | 0 | 0 |
| Ringer’s lactate | Lactated Ringer | 130 | 109 | 0 | 0 |
Ringer’s lactate also has 28 mmol/L lactate, 4 mmol/L K+ and 3 mmol/L Ca2+. Ringer’s acetate (ASERING) also has 28 mmol/L acetate, 4 mmol/L K+ and 3 mmol/L Ca2+.
| Solution | Change in ECF | Change in ICF |
|---|---|---|
| D5W | 333 mL | 667 mL |
| 2/3D & 1/3S | 556 mL | 444 mL |
| Half-normal saline | 667 mL | 333 mL |
| Normal saline | 1000 mL | 0 mL |
| Ringer’s lactate | 900 mL | 100 mL |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
