From the Guidelines
The most common IV fluids include crystalloids and colloids, with balanced crystalloids such as lactated Ringer's and Plasma-Lyte being preferred over normal saline due to their more physiological composition and potential to reduce mortality and kidney injury 1. The choice of IV fluid should be based on the patient's specific condition, electrolyte status, acid-base balance, and hemodynamic needs.
- Normal saline (0.9% NaCl) is widely used for volume replacement and contains 154 mEq/L of both sodium and chloride, making it isotonic to plasma.
- Lactated Ringer's solution more closely resembles plasma composition with sodium (130 mEq/L), potassium (4 mEq/L), calcium (3 mEq/L), chloride (109 mEq/L), and lactate (28 mEq/L), which converts to bicarbonate in the liver, making it useful for patients with metabolic acidosis.
- Dextrose 5% in water (D5W) provides free water and 170 calories per liter, becoming hypotonic once dextrose is metabolized, making it suitable for free water replacement and medication delivery.
- Hypertonic saline (3% or 5% NaCl) is used specifically for treating severe hyponatremia or elevated intracranial pressure.
- Plasma-Lyte is a balanced crystalloid similar to Lactated Ringer's but contains acetate and gluconate instead of lactate, making it useful for patients with liver dysfunction.
- For colloids, albumin (5% or 25%) increases oncotic pressure and maintains intravascular volume longer than crystalloids, while being particularly useful in patients with liver disease or hypoalbuminemia. According to the most recent and highest quality study, balanced crystalloids are associated with reduced mortality in the general population of critically ill patients without cirrhosis 1. Careful monitoring of fluid status, electrolytes, and organ function during administration is crucial to ensure optimal patient outcomes. In patients with severe dehydration, shock, or altered mental status, isotonic intravenous fluids such as lactated Ringer’s and normal saline solution should be administered 1. Additionally, the use of balanced crystalloids may be advantageous over 0.9% sodium chloride in reducing the risk of hyperchloraemic acidosis or kidney injury 1.
From the FDA Drug Label
WARNINGS 50% Dextrose Injection is hypertonic and may cause phlebitis and thrombosis at the site of injection. DESCRIPTION 50% Dextrose Injection, USP is a sterile, nonpyrogenic, hypertonic solution of dextrose in water for injection for intravenous injection as a fluid and nutrient replenisher. The most common IV fluid is Dextrose, specifically 50% Dextrose Injection, which is a hypertonic solution used as a fluid and nutrient replenisher.
- It contains 0.5 g dextrose per mL, delivering 3.4 kcal/gram.
- Administration should be done slowly, preferably through a small-bore needle into a large vein, to minimize venous irritation 2.
- For central venous administration, concentrated dextrose should be administered via central vein only after suitable dilution 2.
- Dextrose is chemically designated C6H12O6 ∙ H2O (D-glucose monohydrate), a hexose sugar freely soluble in water 2.
From the Research
Types of IV Fluids
- Isotonic crystalloids: include 0.9% sodium chloride and balanced salt solutions, such as lactated Ringer's solution 3, 4
- Hypotonic and hypertonic crystalloids: have different concentrations of solutes compared to blood 3
- Colloids: include artificial colloids such as gelatins, and albumin 4
Common IV Fluids
- Normal saline solution (0.9% sodium chloride): commonly used in emergency departments and intensive care units 5, 6
- Lactated Ringer's solution: a balanced salt solution that may be preferred in some patient populations 3, 5, 6
- Balanced salt solutions: may be preferred in some patient populations, such as those with diabetic ketoacidosis 6
Comparison of IV Fluids
- Normal saline solution and lactated Ringer's solution have similar effects on quality of recovery in stable emergency department patients 5
- Lactated Ringer's solution may be associated with faster resolution of high anion gap metabolic acidosis in patients with diabetic ketoacidosis compared to normal saline solution 6
- The choice of IV fluid depends on the individual patient's needs and the specific clinical situation 3, 4, 7