5% dextrose in water (D5W) is typically used as a primary IV fluid for which reason?

• A. Provides free water; it is not a maintenance fluid for volume expansion and becomes hypotonic after metabolism, so it is not used as the sole resuscitative fluid.
• B. Is a maintenance fluid for volume expansion.
• C. Is used as the primary resuscitative fluid in shock.
• D. Is hypertonic fluid.

Answer: (B)

D5W is used mainly as a maintenance fluid because it provides free water. The 5% dextrose in the bag supplies calories, but after the dextrose is metabolized, what’s left is pure water. This water distributes quickly into all body compartments and does not stay in the intravascular space to expand blood volume or serve as a resuscitative fluid. Since it adds little to electrolytes, it’s best for meeting daily water needs rather than expanding circulating volume. For boosting intravascular volume in shock, isotonic crystalloids like normal saline or lactated Ringer’s are preferred.