What is the typical starting dose of dopamine (a catecholamine vasopressor) for a newborn with hypotension?

Dopamine Dosing in Newborns with Hypotension

For newborns with fluid-refractory shock, start dopamine at 5-9 mcg/kg/min and titrate upward as needed. 1

Initial Management Algorithm

Before initiating dopamine, ensure the following steps are completed 1:

• Fluid resuscitation first: Administer 10 cc/kg boluses of isotonic saline or colloid up to 60 cc/kg unless hepatomegaly develops 1
• Correct metabolic derangements: Address hypoglycemia and hypocalcemia 1
• Rule out ductal-dependent lesions: Begin prostaglandin until excluded 1
• Start antibiotics if sepsis is suspected 1

Dopamine Dosing Strategy

Starting Dose: 5-9 mcg/kg/min

The American College of Critical Care Medicine specifically recommends initiating dopamine at 5-9 mcg/kg/min for newborns with fluid-refractory shock 1. This differs from older pediatric patients where starting at 2-5 mcg/kg/min may be appropriate 2.

Critical evidence supporting higher starting doses in newborns:

• Research demonstrates that starting dopamine at <10 mcg/kg/min in hypotensive preterm infants often fails to produce adequate response, and delays may cause further compromise 3
• In one study, only 5 of 12 hypotensive preterm neonates responded to 5 mcg/kg/min, but all responded when the dose was doubled to 10 mcg/kg/min 3
• Another trial showed dopamine achieved target blood pressure at a median dose of 12.5 mcg/kg/min in hypotensive very preterm infants 4

Dose Escalation

If shock persists at 15 minutes despite dopamine 5-9 mcg/kg/min 1:

• Add dobutamine up to 10 mcg/kg/min (rather than increasing dopamine further initially) 1
• This combination approach targets both blood pressure (dopamine) and cardiac output (dobutamine) 1

If shock remains unresolved at 60 minutes 1:

• Switch to epinephrine 0.05-0.3 mcg/kg/min 1
• Dopamine becomes less effective at this stage, and epinephrine provides more potent inotropic and vasopressor effects 1

Dose-Dependent Pharmacology in Newborns

Important caveat: Newborns have different receptor sensitivity and decreased dopamine clearance compared to older children 5:

• 2-5 mcg/kg/min: Predominantly dopaminergic effects (renal/mesenteric vasodilation) with some alpha-adrenergic effects in newborns 2, 5
• 5-10 mcg/kg/min: Beta-adrenergic effects (increased cardiac contractility) become prominent 2
• >10 mcg/kg/min: Alpha-adrenergic effects (peripheral vasoconstriction) predominate 2, 6

Preterm neonates show pronounced alpha- and dopamine-receptor effects even at low doses (2-8 mcg/kg/min), with minimal beta-receptor stimulation until higher doses 5. This explains why starting at 5-9 mcg/kg/min is appropriate for achieving blood pressure goals 1.

Preparation and Administration

Standard preparation using "Rule of 6" 2, 6:

• 0.6 × body weight (kg) = mg of dopamine diluted to 100 mL saline 2, 6
• Then 1 mL/hour = 0.1 mcg/kg/min 2, 6
• Example: For a 3 kg newborn, mix 1.8 mg (6 × 0.3 = 1.8 mg) in 100 mL saline 2, 6

Alternative preparation: 400 mg dopamine in 500 mL D5W, titrated at 2-20 mcg/kg/min 1, 2

Essential Monitoring Requirements

Continuous monitoring is mandatory 2, 6:

• Blood pressure (preferably arterial line) 2
• Heart rate and continuous ECG 2
• Peripheral perfusion assessment 2
• Central venous oxygen saturation (ScvO2) >70% as goal 1
• Superior vena cava flow >40 mL/kg/min or cardiac index >3.3 L/min/m² 1

Critical Safety Considerations

Extravasation risk 2, 6:

• Dopamine causes severe tissue necrosis if extravasated 2, 6
• Have phentolamine immediately available: 0.1-0.2 mg/kg (up to 10 mg) diluted in 10 mL saline for intradermal injection at extravasation site 2, 6
• Protect infusion from light exposure 2
• Never flush or bolus the IV line 2

Maximum dose considerations 6:

• At 20 mcg/kg/min, significant adverse effects become likely, including peripheral/renal/splanchnic vasoconstriction and ischemia 6
• Tachyarrhythmias and ectopic beats increase substantially at doses >10 mcg/kg/min 6
• If approaching 20 mcg/kg/min without adequate response, switch to epinephrine rather than escalating further 1

Comparative Effectiveness

Dopamine vs. Dobutamine in newborns 4, 7:

• Dopamine is more effective than dobutamine for raising blood pressure in hypotensive preterm neonates 4, 7
• In randomized trials, dopamine achieved systolic BP >40 mmHg in significantly more infants than dobutamine 4, 7
• However, dopamine does not increase left ventricular output (actually decreased by 14%), while dobutamine increases it by 21% 4
• This explains the guideline recommendation to add dobutamine if dopamine alone is insufficient 1

Common Pitfalls to Avoid

• Starting too low: Don't waste time with doses <5 mcg/kg/min in newborns with shock, as response is unlikely and delay worsens outcomes 3
• Inadequate fluid resuscitation: Dopamine should never be first-line; ensure adequate volume loading first 1
• Prolonged dopamine monotherapy: If no response by 15 minutes, add dobutamine rather than continuing to escalate dopamine alone 1
• Ignoring cardiac output: Rising blood pressure with dopamine may occur at the expense of cardiac output; monitor perfusion markers, not just BP 4
• Delaying epinephrine: If shock persists at 60 minutes despite dopamine/dobutamine, switch to epinephrine rather than continuing ineffective therapy 1