What is the difference between using D5 (Dextrose 5%) half normal saline (0.45% sodium chloride solution) versus normal saline (0.9% sodium chloride solution)?

From the Guidelines

The choice between D5 half normal saline and normal saline should be based on the patient's specific needs, with D5 half normal saline preferred for glucose supplementation and free water while limiting sodium intake, and normal saline better for pure volume replacement or when higher sodium concentrations are required. The main difference between D5 half normal saline (D5 0.45% NaCl) and normal saline (0.9% NaCl) is their composition and clinical applications. D5 half normal saline contains 5% dextrose (glucose) and half the sodium concentration (77 mEq/L) of normal saline, which contains 154 mEq/L of sodium. According to a study published in Pediatrics 1, isotonic solutions like normal saline have a sodium concentration similar to plasma, and are recommended for preventing hyponatremia in hospitalized children.

In terms of clinical applications, D5 half normal saline provides both free water and some electrolytes along with calories (170 kcal/L), making it useful for patients who need fluid replacement with some glucose support, such as those with hypoglycemia, hypernatremia, or mild dehydration with elevated sodium levels. Normal saline, on the other hand, is isotonic and primarily used for volume expansion in hypovolemic states, treating metabolic alkalosis, or diluting medications. A study published in Kidney International 1 suggests that isotonic crystalloids like normal saline are preferred over colloids for expansion of intravascular volume in patients at risk for acute kidney injury.

Key points to consider when choosing between D5 half normal saline and normal saline include:

• The patient's sodium level and need for sodium restriction
• The patient's glucose level and need for glucose supplementation
• The patient's volume status and need for volume replacement
• The patient's kidney function and risk for acute kidney injury. In general, normal saline is a safer choice for most patients, as it is less likely to cause hyponatremia and is more effective for volume replacement. However, the decision should be individualized based on the patient's specific needs and clinical context.

From the Research

Difference between using d5 half normal saline or just normal saline

• The use of d5 half normal saline versus normal saline depends on the clinical context and the patient's condition 2, 3, 4.
• D5 half normal saline contains 5% dextrose and 0.45% saline, which can help provide calories and maintain hydration, but may cause hyperglycemia in some patients 2.
• Normal saline, on the other hand, is isotonic and can help maintain hydration without causing hyperglycemia, but may not provide the same caloric benefits as d5 half normal saline 3, 4.
• In patients with dehydration, d5 half normal saline may be used to provide both hydration and calories, while normal saline may be used to provide hydration only 3.
• In patients with sepsis-induced hypotension, lactated Ringer's solution or normal saline may be used for initial fluid resuscitation, with lactated Ringer's solution potentially associated with improved survival 5.
• The choice of fluid therapy should be individualized based on the patient's clinical condition, laboratory results, and other factors, and should be guided by evidence-based guidelines and protocols 4, 5.

Metabolic Effects

• D5 half normal saline can cause significant hyperglycemia, even in non-diabetic patients, due to the high glucose content 2.
• Normal saline, on the other hand, does not contain glucose and is less likely to cause hyperglycemia 3, 4.
• Lactated Ringer's solution can help maintain plasma bicarbonate levels and prevent acidosis, while normal saline may not have the same effect 4, 5.

Clinical Applications

• D5 half normal saline may be used in patients with mild to moderate dehydration who require both hydration and calories 3.
• Normal saline may be used in patients with severe dehydration or sepsis-induced hypotension who require rapid fluid resuscitation 3, 5.
• Lactated Ringer's solution may be used in patients with sepsis-induced hypotension who require initial fluid resuscitation and may benefit from its potential association with improved survival 5.