ICU Essentials · Vasoactive Agents
Vasopressor & Inotrope Dosing
Mechanism · Dose Ranges · Indications · Receptor Profile
Norepinephrine
Levophed
α1 >> β1
Potent vasoconstrictor
↑ SVR · ↑ MAP
Minimal ↑ HR
Dose Range
0.01–3
mcg/kg/min
Indications
Septic shock
Distributive shock
Vasodilatory shock
Notes
First-line vasopressor
Central line preferred
May ↓ mesenteric flow
Epinephrine
Adrenaline
α1 + β1 + β2
↑ HR · ↑ CO · ↑ SVR
Bronchodilator
↑ Lactate (metabolic)
Dose Range
0.01–1
mcg/kg/min
Indications
Anaphylaxis
Cardiogenic shock
Refractory septic shock
Cardiac arrest: 1 mg IV q3–5min
Notes
↑ Lactate — not sign of shock progression
Arrhythmogenic
IM anaphylaxis: 0.3–0.5 mg
Vasopressin
ADH / Pitressin
V1 receptor
Non-catecholamine
↑ SVR via V1
No ↑ HR · ↑ CO
Dose Range
0.03–0.04
U/min (fixed)
Max: 0.06 U/min
Indications
Septic shock adjunct
Norepi-sparing
Add when norepi
≥0.25 mcg/kg/min
Notes
Not titrated by effect
Risk: mesenteric ischemia at high doses
Hepatic failure → caution
Dobutamine
Dobutrex
β1 >> β2
Positive inotrope
↑ CO · ↑ HR
↓ SVR (β2 effect)
Dose Range
2–20
mcg/kg/min
Indications
Cardiogenic shock
Septic shock + low CO
Acute decompensated HF
Notes
Vasodilatory — may ↓ BP
Combine with vasopressor if hypotensive
Tachycardia common
Phenylephrine
Neo-Synephrine
Pure α1
Pure vasoconstriction
↑ SVR · ↑ MAP
↓ HR (reflex)
Dose Range
0.4–9.1
mcg/kg/min
Bolus: 50–200 mcg IV
Indications
Anesthesia-induced hypotension
Neurogenic shock
SVT with hypotension
Notes
No β activity — avoid if low CO
Reflex bradycardia
Preferred in tachyarrhythmias
📊 Receptor Profile Comparison
Agentα1β1β2V1DA
Norepinephrine
Epinephrine
Vasopressin
Dobutamine
Phenylephrine
● High ● Moderate ● None
⚠️ Critical Warnings
All vasopressors: central line preferred for infusion
Peripheral vasopressors (norepi, phenyl) short-term OK with 18G+ IV — monitor closely
Avoid dopamine in septic shock — worse outcomes (SOAP-II)
High-dose vasopressin (>0.06 U/min) → digital/mesenteric ischemia
Dobutamine + hypotension → add vasopressor first
Taper vasopressors gradually — abrupt discontinuation → rebound hypotension
CCM Notes · FOAMed · Critical Care Clinical Reference
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Educational use only — Verify doses per local formulary