What is D5W?
D5W, or Dextrose 5% in Water, is a common intravenous fluid providing hydration and some nutrients. The 5% concentration means there are 5 grams of dextrose for every 100 milliliters (mL) of water. It is used for various purposes including hydration and administering medications.
The Calculation: How much dextrose is in 1 l of D5W?
The amount of dextrose in 1 liter of D5W is based on its 5% concentration. Given that 1 liter equals 1000 mL and the solution is 5 grams per 100 mL, a straightforward calculation shows that 1 liter of D5W contains 50 grams of dextrose.
Medical Uses and Considerations for D5W
D5W is used for free water replacement, correcting high sodium levels (hypernatremia), or preventing hypoglycemia temporarily. It can also serve as a vehicle for medications. It is not a primary source of nutrition.
Comparison Table: D5W vs. Other Common IV Fluids
| Feature | D5W (5% Dextrose in Water) | Normal Saline (0.9% NaCl) | Lactated Ringer's (LR) |
|---|---|---|---|
| Dextrose (g/L) | 50 | 0 | 0 |
| Electrolytes | None | Sodium, Chloride | Sodium, Potassium, Calcium, Chloride, Lactate |
| Tonicity | Isotonic initially, then becomes hypotonic | Isotonic | Isotonic |
| Primary Use Case | Free water replacement, vehicle for meds | Volume resuscitation, dehydration | Fluid and electrolyte replacement |
| Calories (kcal/L) | 170 | 0 | 0 |
Nutritional and Metabolic Effects
A liter of D5W provides around 170 kilocalories, considered minimal. The body quickly metabolizes the glucose, leaving free water. This causes D5W, initially isotonic, to function hypotonicly in the body, useful for conditions like hypernatremia.
Conclusion
One liter of D5W contains 50 grams of dextrose, a figure derived from its 5% concentration. This fact is vital for the safe administration of this common IV fluid. D5W offers minimal calories and provides free water but lacks electrolytes, requiring careful clinical assessment. Understanding its composition is key in IV fluid therapy.
Further reading on intravenous fluid therapy principles is available from Cleveland Clinic {Link: Cleveland Clinic https://my.clevelandclinic.org/health/treatments/21635-iv-fluids}.
