Table of Contents

1. How Intravenous Fluids Benefit You
2. Types of IV fluids
3. Crystalloid Solutions
4. Hypotonic
5. Hypertonic
6. Isotonic
7. Colloid Solutions

IV therapy delivers effective results because just one drip bag is packed with vitamins, minerals and electrolytes designed to support your health and wellness. But when you consider all the high-quality ingredients in IV fluids, don’t overlook the fluids themselves. If you know what’s in IV fluids, you’ll have a deeper understanding of the profound effects IV therapy can have on your mind and body. 

Types of IV fluids

You can group IV solutions into two categories: crystalloid and colloid. Both are sterile solutions that can be customized with various ingredients. However, they have different compositions, which have distinct reactions in the body. Crystalloid fluids interact with cells because the solutions carry their tiny particles through the semipermeable cellular membrane. However, the particles in colloid fluids stay in your bloodstream because they are too large to enter the membrane.

Crystalloid Solutions

These are common IV fluids because they are affordable and accessible, as well as shelf-stable and free of allergens. There are three subgroups of IV fluids in the crystalloid category: hypotonic, hypertonic and isotonic.

Hypotonic 

These intravenous solutions increase fluid levels within cells. This is particularly helpful for conditions such as diabetes, which may reduce levels of cellular fluid. Cells can’t maintain proper function when they don’t achieve osmosis and lose too much fluid. The following crystalloid IV fluids are all hypotonic:

• 0.45% NaCl

Sodium chlorine (aka saline) is the main ingredient in all hypotonic solutions. Compared to isotonic and hypertonic IVs, the hypotonic fluids are lower in sodium chlorine. Consequently, these solutions are used in situations where patients have hypernatremia or high sodium chloride levels. If the body gets too much fluid, which can happen with hypotonic solutions, it may negatively affect electrolyte levels or cause edemas. This particular fluid should not be used with patients who have heart or kidney failure.

• 0.33% NaCl

While a 0.33% solution can help people with impaired kidney function retain water, it’s not beneficial for those with more severe kidney disorders. There is a risk of pulmonary edemas with this group, as well as people with heart problems.

• 0.225% NaCl

This is a common type of IV fluid for pediatric health needs. It’s typically not used on its own but in tandem with a form of glucose called dextrose. 

• 2.5% dextrose in water

IV therapy is incredibly effective at treating dehydration, caused by any number of factors, such as hangovers, illness, strenuous physical activity, migraines and other health conditions. The 2.5% dextrose in water solution nets great results in relieving dehydration symptoms. 

Isotonic

The volume of an isotonic solution resembles that of your blood plasma. This composition enables isotonic solutions to maintain balanced osmotic pressure with equal amounts of fluids, both inside and outside of cells. These are two of the most popular isotonic fluids used in IV therapy:

• Lactated Ringer’s

You can often find this fluid in emergency rooms, ambulances and other places dealing with critical health issues. Lactated Ringer’s helps people with extensive burns, severe injuries or major loss of blood. A variation of this isotonic fluid is called Ringer’s Solution, and it is free of lactate. 

• 0.9% NaCl

Also called a normal saline solution, it works well at alleviating dehydration symptoms.

Two other isotonic solutions are used in more specific circumstances:

• 5% dextrose in water

This fluid supports hospitalized patients who can’t eat normal food by supplying them with calories. 

• PlasmaLyte

This solution is paired with red blood cells for IV treatment. It shares almost identical electrolyte levels with blood plasma in the body.

Colloid Solutions

Colloid solutions stay in the bloodstream and provide nutrients to help patients regain strength. They also don’t carry a risk of pulmonary edemas by swelling the body with too much fluid. Colloid IV fluids include:

• 5% albumin
• 25% albumin
• Hetastarch
• Hespan
• Low-molecular weight dextran
• High-molecular weight dextran