Vasopressors

Norepinephrine

Indication

Septic shock

Dosing

Start 2mcg/min
- Incr by 1-2mcg/min q3-5min prn
- Max dose is 30mcg/min
Replace volume before starting

Adverse Effects

If extravasates use phentolamine 5-10mg into affected area

Mechanism of Action

Alpha and beta1 agonist
- Incr contractility, HR
- Arterial/venous vasoconstriction

Dopamine

Indication

Hypotension caused by:
- Septic shock
- MI
- Trauma
- Heart failure

Contraindication

Tachyarrhythmias

Dosing

Use lowest dose possible (prevent tachyphylaxis)
- 3-20mcg/kg/min works for most
May use in peripheral IV temporarily
- Avoid using in same line as alkaline infusions

Adverse Effects

Low doses
- Hypotension
High doses
- Hypertension, ectopic beats
Tissue necrosis (if extravasates)
- If occurs use phentolamine 5-10mg in affected area

Mechanism of Action

0-5mcg/kg/min
- Vasodilation (renal, mesenteric, coronary)
5-10mcg/kg/min
- Beta1, alpha1 agonist
  - Incr CO, contractility, vasoconstriction
>10mcg/kg/min
- Alpha effects predominate

Dobutamine

Indication

Cardiogenic shock
Low-output heart failure

Dosing

2-20mcg/kg/min
- 10mcg works for most
May use in peripheral IV

Adverse Effects

Modest incr in HR/BP
PVCs

Mechanism of Action

Primarily B1 and B2 agonist
- Increases CO via incr contractility

Phenylephrine

Indication

Shock

Dosing

Start 100-200mcg/min then taper down
- 40-60mcg/min works for most

Adverse Effects

Bradycardia
If extravasates use phentolamine

Mechanism of Action

Alpha agonist
- Vasoconstriction w/ reflex decr HR
  - May decrease stroke volume

MAP = SVR X CO

Agent	SVR	BP	PCW	CO
Dopa >5	++	++	+	-
Dopa <5	--	-
Dobuta	--	+/-	-	+
D+D (7.5/2.5-5)	+	+/-	+
Norepi	++++	++	++	--

DOPA >5 watch for inc HR/PVC
DOPA<5 coronary vasodilator

Dobutamine = 2.5-5; for RV infarct; develop tachyphylaxis

Norepinephrine- large bore IV; Inc HR

Milrinone= similar to dobutamine

Sepsis: Norepi or Dopamine

Cardiogenic: Dobutamine

Peds: usually prefer Dopamine, then Epi

Source

Tintinalli

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