Which fluid should never be used to replace volume?

Which fluid should never be used to replace volume?

• A. Normal saline
• B. Lactated Ringer's
• C. D5W
• D. 0.45% NaCl

Answer: (C)

The fundamental idea is to choose a fluid that actually expands the extracellular and intravascular volume during resuscitation. D5W should never be used to replace volume because, after the dextrose is metabolized, what remains is free water. It does not raise extracellular fluid volume and can dilute plasma sodium, risking hyponatremia and even cerebral edema in vulnerable patients. In contrast, normal saline and lactated Ringer's are isotonic crystalloids that stay mainly in the extracellular space and effectively increase circulating volume, making them appropriate for volume resuscitation. The hypotonic 0.45% NaCl can also contribute to volume but can shift water into cells and isn’t ideal for rapid resuscitation in many situations. So the fluid not suitable for volume replacement is D5W because it becomes free water rather than a volume-expanding solution.

The fundamental idea is to choose a fluid that actually expands the extracellular and intravascular volume during resuscitation. D5W should never be used to replace volume because, after the dextrose is metabolized, what remains is free water. It does not raise extracellular fluid volume and can dilute plasma sodium, risking hyponatremia and even cerebral edema in vulnerable patients.

In contrast, normal saline and lactated Ringer's are isotonic crystalloids that stay mainly in the extracellular space and effectively increase circulating volume, making them appropriate for volume resuscitation. The hypotonic 0.45% NaCl can also contribute to volume but can shift water into cells and isn’t ideal for rapid resuscitation in many situations. So the fluid not suitable for volume replacement is D5W because it becomes free water rather than a volume-expanding solution.