Vasoactive Infusions in the PICU: Dosing, Pharmacology, and the Vasoactive-Inotropic Score

By Daniel Diaz-Gil, MD· March 2026 · 3 min read

Summary

  • Vasopressor and inotrope selection should match the physiology (poor contractility, low systemic vascular resistance, elevated pulmonary vascular resistance), not just target a blood pressure number.
  • Dopamine (2-20 mcg/kg/min) has dose-dependent, unpredictable receptor effects between patients; low-dose "renal-dose" dopamine does not protect kidney function and is no longer used for that purpose.
  • Dobutamine (2-20 mcg/kg/min) is pure inotropy with vasodilation, useful in cardiogenic shock when BP is not critically low.
  • Norepinephrine (0.01-1+ mcg/kg/min) is now favored as first-line for pediatric vasodilatory shock over epinephrine, with comparable efficacy and less tachycardia [1].
  • Milrinone (0.25-0.75 mcg/kg/min) reduces both systemic and pulmonary vascular resistance while augmenting contractility, and is standard for prevention of low cardiac output syndrome after congenital heart surgery [2].
  • The Vasoactive-Inotropic Score (VIS) quantifies total pharmacologic support and its trend tracks clinical trajectory [3].

Agents

Agent Dose range Mechanism Primary role Key limitation
Dopamine 2-20 mcg/kg/min Dopaminergic effect at 2-5 mcg/kg/min, beta effect at 5-10, alpha effect above 10 Chronotropic support in bradycardic shock Response is unpredictable between patients and does not separate cleanly by dose
Dobutamine 2-20 mcg/kg/min Beta-agonist inotropy with vasodilation Cardiogenic shock with preserved blood pressure Vasodilation can drop pressure; frequently requires a paired vasopressor
Epinephrine 0.01-1+ mcg/kg/min Beta-dominant at 0.01-0.1 mcg/kg/min, alpha-dominant at higher doses Combined inotropy and vasoconstriction in one infusion High doses raise heart rate and myocardial oxygen demand, increase arrhythmia risk, and prolonged use causes lactic acidosis
Norepinephrine 0.01-1+ mcg/kg/min Alpha-dominant vasoconstriction with preserved beta/contractility First-line vasopressor for septic and other vasodilatory shock [1] Requires a central line; less tachycardia than epinephrine but not free of it
Milrinone 0.25-0.75 mcg/kg/min Phosphodiesterase inhibitor; inotropy plus systemic and pulmonary vasodilation Post-op low cardiac output syndrome, and pulmonary hypertension layered on heart failure [2] Vasodilation can reduce systemic pressure; often paired with a vasopressor

Caution. Renal-dose dopamine (2-5 mcg/kg/min) does not protect renal function despite the theoretical basis for the practice, and dopamine's effects vary unpredictably between patients at any given dose.

Clinical pearl. Dopamine's main remaining role in the PICU is chronotropic support for bradycardic shock, not routine first-line pressor use.

Scoring

VIS = Dopamine + Dobutamine + (100 × Epinephrine) + (100 × Norepinephrine) + (10 × Milrinone) + (10,000 × Vasopressin)

  • All catecholamine doses are entered in mcg/kg/min; vasopressin in U/kg/min.
  • The weighting reflects the relative potency of each agent: epinephrine and norepinephrine are weighted 100-fold, vasopressin 10,000-fold.
  • Higher VIS correlates with greater illness severity and worse prognosis [3].
  • A rising VIS during ongoing resuscitation indicates the patient is not responding to current management; a falling VIS, even gradually, generally indicates recovery.
  • VIS is used for team communication, quality metrics, and research standardization [3].

Open the VIS Score Calculator →

Management

Combine agents by matching the drug to the dominant physiologic problem:

  • Septic shock with poor contractility: norepinephrine as the primary vasopressor, with low-dose dobutamine added for inotropy if ejection fraction is reduced [1].
  • Cardiogenic shock: dobutamine or milrinone for combined inotrop

References

  1. Weiss SL, et al. Surviving Sepsis Campaign International Guidelines for the Management of Septic Shock and Sepsis-Associated Organ Dysfunction in Children. Pediatr Crit Care Med. 2020;21(2):e52-e106. doi:10.1097/PCC.0000000000002198
  2. Hoffman TM, et al. Efficacy and safety of milrinone in preventing low cardiac output syndrome in infants and children after corrective surgery for congenital heart disease. Circulation. 2003;107(7):996-1002. doi:10.1161/01.CIR.0000051365.81920.28
  3. Gaies MG, Gurney JG, Yen AH, et al. Vasoactive-inotropic score as a predictor of morbidity and mortality in infants after cardiopulmonary bypass. Pediatr Crit Care Med. 2010;11(2):234-238. doi:10.1097/PCC.0b013e3181b806fc