What is the recommended concentration and administration protocol for dopamine or dobutamine infusion in a 1.5kg neonate?

Dopamine and Dobutamine Infusion Preparation for a 1.5kg Neonate

For a 1.5kg neonate, dopamine and dobutamine infusions should be prepared at a concentration of 1000 μg/mL (1 mg/mL) by adding 60 mg of the drug to 60 mL of compatible diluent such as D5W or normal saline. 1, 2, 3

Preparation Protocol

Dopamine Preparation:

1. Use a 60 mg vial of dopamine
2. Dilute in 60 mL of D5W or normal saline to create a 1000 μg/mL (1 mg/mL) solution
3. Ensure solution is clear and not darker than slightly yellow 3
4. Use within 24 hours of preparation

Dobutamine Preparation:

1. Use a 60 mg vial of dobutamine
2. Dilute in 60 mL of D5W or normal saline to create a 1000 μg/mL (1 mg/mL) solution
3. Protect bottle from light with protective foil (IV tubing does not need protection) 1
4. Use within 24 hours of preparation 2

Administration Guidelines

Dopamine Administration:

• Starting dose: 2-5 μg/kg/min (0.3-0.75 mL/hr for a 1.5kg neonate)
• Titration range: 2-20 μg/kg/min (0.3-3.0 mL/hr)
• Effects by dose range:
  • Low dose (1-5 μg/kg/min): Dopaminergic and β-adrenergic effects (renal perfusion)
  • Higher doses: α-adrenergic effects predominate 1

Dobutamine Administration:

• Starting dose: 2-5 μg/kg/min (0.3-0.75 mL/hr for a 1.5kg neonate)
• Titration range: 2-20 μg/kg/min (0.3-3.0 mL/hr)
• Maximum dose: 20 μg/kg/min (rarely up to 40 μg/kg/min) 2

Important Safety Considerations

1. Always use an infusion pump, preferably a volumetric pump, never gravity-regulated infusion 3

2. Infuse into a large vein whenever possible to prevent extravasation 3

3. Monitor continuously for:

   • Heart rate and blood pressure
   • Urine output
   • Signs of extravasation
   • Arrhythmias or tachycardia 1

4. Extravasation management: 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

5. Titration: Adjust dose based on clinical response; titrate at intervals of a few minutes 2

Clinical Indications and Considerations

• Dopamine: Preferred for cardiogenic/distributive shock with hypotension; more effective for increasing blood pressure 1, 4

• Dobutamine: Preferred for cardiogenic shock with adequate blood pressure; produces greater increase in cardiac output and systemic blood flow 1, 5

Cautions and Potential Adverse Effects

• Dopamine: May cause arrhythmias, hypertension, and at high doses (>20 μg/kg/min) can cause peripheral, renal, and splanchnic vasoconstriction 1

• Dobutamine: May cause tachyarrhythmias, ectopic beats, hypotension, and hypertension 1

• Both drugs: Extravasation can result in severe skin injury 1

Remember that neonates may have diminished response to dopamine compared to older children due to maturational differences in norepinephrine stores 6. Careful monitoring is essential to ensure optimal therapeutic effect while minimizing adverse reactions.