What is the infusion preparation of dopamine for a 2.5kg newborn starting at 5 micrograms (mcg) per kilogram per minute?

Dopamine Infusion Preparation for a 2.5kg Newborn at 5 mcg/kg/min

For a 2.5 kg newborn requiring dopamine at 5 mcg/kg/min, use the "Rule of 6" method: multiply 0.6 × 2.5 kg = 1.5 mg of dopamine, dilute to a total volume of 100 mL with normal saline or D5W, then infuse at 5 mL/hr to deliver exactly 5 mcg/kg/min. 1

Preparation Methods

Rule of 6 Method (Preferred for Neonates)

• Calculate drug amount: 0.6 × body weight (kg) = mg of dopamine needed 1
  • For 2.5 kg: 0.6 × 2.5 = 1.5 mg dopamine
• Dilute to 100 mL total volume with normal saline or D5W 1
• Infusion rate: 1 mL/hr delivers 0.1 mcg/kg/min 1
  • For 5 mcg/kg/min: infuse at 5 mL/hr
  • For 10 mcg/kg/min: infuse at 10 mL/hr
  • For 20 mcg/kg/min: infuse at 20 mL/hr

Alternative Standard Concentration Method

• Prepare 400 mg dopamine in 500 mL D5W (concentration = 800 mcg/mL) 1
• For 2.5 kg at 5 mcg/kg/min:
  • Desired dose = 5 mcg/kg/min × 2.5 kg = 12.5 mcg/min
  • Convert to mL/hr: (12.5 mcg/min × 60 min/hr) ÷ 800 mcg/mL = 0.94 mL/hr

Critical Administration Requirements

Equipment and Monitoring

• Use only an infusion pump, preferably volumetric - never rely on gravity drip 2
• Infuse into a large vein (antecubital fossa preferred) to prevent extravasation 2
• Continuous hemodynamic monitoring is mandatory, including blood pressure, heart rate, and ECG 1
• Consider arterial line placement for continuous blood pressure monitoring 1
• Protect solution from light by covering the bottle/syringe with protective foil 1

Safety Precautions

• Monitor closely for extravasation - can cause severe tissue necrosis 1, 2
• If extravasation occurs: inject phentolamine 0.1-0.2 mg/kg (up to 10 mg) diluted in 10 mL normal saline intradermally at the site 1, 2
• Avoid accidental bolus - exercise extreme caution to prevent flushing the IV line 1
• Do NOT add sodium bicarbonate or alkalinizing substances - dopamine is inactivated in alkaline solution 2

Dosing Strategy for Neonates

Initial Dosing (2-5 mcg/kg/min)

• Begin at 2-5 mcg/kg/min for most neonates 3, 1, 2
• This range primarily stimulates dopaminergic receptors (renal/mesenteric vasodilation) with mild β-adrenergic effects 3, 1

Dose Escalation

• Increase gradually in 5-10 mcg/kg/min increments if needed 2
• Intermediate doses (5-10 mcg/kg/min): β-adrenergic effects predominate (increased cardiac contractility) 3, 1
• Higher doses (>10 mcg/kg/min): α-adrenergic effects cause peripheral vasoconstriction 3, 1
• Maximum therapeutic range: up to 20 mcg/kg/min 3, 1

When to Reduce or Stop

• Diminishing urine output despite adequate blood pressure 2
• Development of tachycardia or new arrhythmias 2
• Excessive vasoconstriction at rates >20 mcg/kg/min 1
• Marked decrease in pulse pressure (disproportionate rise in diastolic pressure) 2

Common Pitfalls to Avoid

• Using gravity drip instead of infusion pump - leads to uncontrolled dosing 2
• Infusing through small peripheral veins (hand/ankle) - increases extravasation risk 2
• Failing to protect solution from light - causes drug degradation 1
• Not monitoring for extravasation continuously - delayed recognition worsens tissue injury 1, 2
• Abrupt discontinuation - may cause marked hypotension; taper gradually while expanding blood volume 2

Special Considerations for Neonates

• In marked circulatory instability or decompensated shock, epinephrine or norepinephrine may be preferable to dopamine 1
• Ensure adequate volume resuscitation before or concurrent with dopamine initiation 2
• The Rule of 6 method is particularly advantageous in neonates because it minimizes fluid volume while allowing precise titration 1
• For this 2.5 kg infant at 5 mcg/kg/min using Rule of 6: the hourly fluid intake is only 5 mL/hr, which is appropriate for neonatal fluid management 1