Unlocking IV Solutions

IV administration remains essential to administering drugs and rehydrating the patient because it is fast, and the effect occurs in minutes. It is beneficial when prompt treatment is needed, such as in emergencies. Also, there is no first-pass metabolism with IV drug administration. Hence, the administered drug is well absorbed.

Types of Solutions

The human body is a fascinating reservoir containing water that accounts for approximately 50-60% of its overall composition. This essential fluid is ingeniously allocated into two distinct compartments: the extracellular and intracellular spaces, separated by the critical boundary of the plasma membrane. Within the extracellular compartment, the distribution is further nuanced—20% exists as plasma, while 80% fills the interstitial spaces surrounding cells. Meticulous fluid intake and balance management become paramount for patients facing critical illness or those unable to consume nutrients orally. In such cases, IV solutions are vital for maintaining physiological equilibrium.

Hypotonic Solutions

Hypotonic solutions have an osmotic concentration of less than 250 milliosmoles per liter (mOsm/L). Different types of hypotonic solutions include 2.5% dextrose in water, 0.25% sodium chloride solution, 0.33% sodium chloride solution, and 0.45% sodium chloride solution.

The hypotonic solution hydrates the cells by pulling fluid from the vascular space to the cellular space.

Hypotonic solutions are indicated in the treatment of hypertonic dehydration.

Nursing intervention/concern: When administering a hypotonic solution, verify the patient is not hypotensive because it can lower blood pressure. It can lower blood pressure by shifting the fluid from the vascular to the cellular space.

Isotonic Solutions

Isotonic solutions have an osmotic concentration of 250-375 mOsm/L. They are different types, such as 5% dextrose in water, 0.9% sodium chloride solution, Ringer’s solution, and Lactated Ringer’s solution.

The isotonic solution hydrates the extracellular compartment and replaces fluid volume without disrupting the intracellular and interstitial volume. That happens because it is isotonic to the osmolar concentration of the cell.

Isotonic solutions are indicated in treating vascular dehydration and replacing sodium and chloride ions.

Nursing interventions/concerns: Use isotonic solutions with caution in patients who are fluid-overloaded or would be compromised if vascular volume increases, such as renal and cardiac patients.

5% dextrose in water is isotonic when infused, but when it metabolizes, it becomes hypotonic.

Hypertonic Solutions

Hypertonic solutions have an osmotic concentration of greater than 375 mOsm/L.

The hypertonic solutions are of different types, such as 5% dextrose in 0.45% sodium chloride solution, 5% dextrose in 0.9% sodium chloride solution, 5% dextrose in lactated Ringer’s solution, 10% dextrose in water, 20% dextrose in water, 50% dextrose in water, 70% dextrose in water, 3% sodium chloride solution and 5% sodium chloride solution.

The hypertonic solution draws out fluid from the intracellular space, leading to increased extracellular volume both in the vascular and interstitial space.

Hypertonic solutions are indicated in treating hypotonic dehydration, circulatory collapse, and increased fluid shift from interstitial to vascular space.

Nursing interventions/concerns: Hypertonic solutions can be very irritating to the veins. Therefore, monitor the IV site for inflammation. These solutions should also be infused slowly, especially in vulnerable patients, because they can cause circulatory overload.

In patients with glucose intolerance, hypertonic solutions can increase serum glucose concentration. That makes glucose monitoring imperative.

Plasma Expanders

These solutions include solutions such as Dextran 70 (isotonic), Dextran 40 (isotonic), 10% mannitol (hypertonic), 20% mannitol (hypertonic), 5% albumin, 25% albumin, 6% hetastarch in 0.9% sodium chloride, and 10% hetastarch in 0.9% sodium chloride.

Plasma expander solution increases the volume in the vascular space and draws out fluid from the intracellular space. That leads to increased extracellular volume both in the vascular and interstitial space.

Plasma expanders are indicated in treating hypotonic dehydration, circulatory collapse, and increased fluid shift from interstitial to vascular space.

Nursing interventions/concerns: With plasma expander therapy, monitor the patient for circulatory overload and hypersensitivity reactions, and do not mix any medications with these solutions. Plasma expanders can be very irritating to the veins. Therefore, monitor the IV site for inflammation. Infuse these solutions slowly, especially in vulnerable patients, because they can cause circulatory overload.

These solutions can also increase serum glucose concentration, so glucose monitoring is imperative.

The Bottom Line

IV fluids are essential in keeping the patient hydrated and maintaining an adequate fluid balance. It is often used in injured patients and those who are sick, dehydrated, undergoing surgeries, or can not take the fluids orally.

Be vigilant with IV administration as it can lead to fluid overload, especially in patients with liver, kidney, and cardiac diseases.

About the Author:

Mariya Rizwan is an experienced pharmacist who has been working as a medical writer for four years. Her passion lies in crafting articles on topics ranging from Pharmacology, General Medicine, Pathology to Pharmacognosy.

Mariya is an independent contributor to CEUfast’s Nursing Blog Program.

Please note that the views, thoughts, and opinions expressed in this blog post are solely of the independent contributor and do not necessarily represent those of CEUfast. This blog post is not medical advice. Always consult with your personal healthcare provider for any health-related questions or concerns.

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