What is the maximum infusion rate of D5W (Dextrose 5% in Water) for an adult patient weighing 104 kg with no significant medical history?

Maximum D5W Infusion Rate for 104 kg Patient

For a 104 kg adult with no significant medical history, the maximum safe infusion rate of D5W is 520 mL/hour (0.5 g/kg/hour), though standard maintenance rates of 100-150 mL/hour are typically sufficient for most clinical scenarios. 1

Standard Maintenance Infusion Rates

• The typical maintenance rate for D5W is approximately 100 mL/hour for adults, which provides sufficient glucose (5 grams/hour) to prevent hypoglycemia while avoiding hyperglycemia 2, 3
• This translates to 100 mL/kg per 24 hours, or roughly 4.2 mL/kg/hour for maintenance fluid therapy 2, 3
• For your 104 kg patient, this would be approximately 437 mL/hour for maintenance, though 100-150 mL/hour is the practical standard 2, 3

Maximum Physiologic Infusion Rate

The FDA-approved maximum rate at which dextrose can be infused without producing glycosuria is 0.5 g/kg/hour 1. For D5W (which contains 5 grams of dextrose per 100 mL):

• Maximum rate = 0.5 g/kg/hour × 104 kg = 52 grams/hour
• This equals 1,040 mL/hour of D5W 1

However, the FDA notes that approximately 95% of dextrose is retained when infused at 0.8 g/kg/hour, which would be 1,664 mL/hour for your patient 1. The lower rate of 0.5 g/kg/hour (520 mL/hour) is recommended to avoid glycosuria.

Clinical Context Adjustments

For Diabetic Ketoacidosis

• Once serum glucose reaches 200-250 mg/dL during DKA treatment, D5W-containing fluids can be infused at 4-14 mL/kg/hour 2, 3
• For your 104 kg patient: 416-1,456 mL/hour to maintain glucose in target range while continuing insulin therapy 2, 3

For Hypoglycemia Treatment

• After initial correction with concentrated dextrose boluses, continuous D5W at 100 mL/hour prevents recurrent hypoglycemia 2, 3

For Cardiac or Renal Compromise

• Limit D5W rates to 100 mL/hour or less and monitor closely for fluid overload 2, 3
• This is critical as D5W provides free water that can exacerbate volume overload in compromised patients 2, 3

Critical Monitoring Requirements

• Monitor blood glucose every 1-2 hours when initiating D5W infusions to ensure the rate is appropriate 2, 3
• Even a relatively small volume of 500 mL D5W can cause significant hyperglycemia (>10 mmol/L in 72% of patients) within 15 minutes 4
• Check serum potassium and sodium levels carefully, as dextrose administration causes electrolyte shifts 5

Important Clinical Caveats

• D5W is hypotonic (provides free water) and should not be used for resuscitation of hypotensive patients 6
• Avoid using D5W in patients with cardiac or CNS ischemia, as dextrose solutions may exacerbate cellular ischemic damage 6
• For peripheral vein administration, infusion should be made slowly to minimize vein irritation 1
• Never abruptly discontinue D5W infusion in patients receiving it for hypoglycemia prevention; reduce rate by 50% over 30 minutes before stopping to prevent rebound hypoglycemia 5

Practical Algorithm for Rate Selection

1. Standard maintenance (no specific indication): 100-150 mL/hour 2, 3
2. Hypoglycemia prevention: 100 mL/hour 2, 3
3. DKA with glucose 200-250 mg/dL: 416-1,456 mL/hour (4-14 mL/kg/hour) 2, 3
4. Cardiac/renal compromise: ≤100 mL/hour 2, 3
5. Absolute maximum (avoid glycosuria): 520 mL/hour (0.5 g/kg/hour) 1

For your 104 kg patient with no significant medical history, start at 100-150 mL/hour and do not exceed 520 mL/hour without specific clinical indication and close glucose monitoring.