Cite this article as:
Marc Anders. Inotropes and vasopressors, Don't Forget the Bubbles, 2013. Available at: https://doi.org/10.31440/DFTB.3876
Definition:
Inotropes: sympathomimetic agent which act on the sympathetic (or adrenergic) nervous system (β-receptors) resulting in positive inotropic (increase in contractility), chronotropic (increase in heart rate), dromotropic (increase in conduction of impulse) and lusitropic effect (improved diastolic relaxation)
Vasopressors: sympathomimetic agent which act on the sympathetic (or noradrenergic) nervous system (α-receptors) resulting in vasoconstrictor effect
The ideal vasoactive support agent: effect on cardiac output/effect on SVR/effect on myocardial oxygen consumption/no tachyphylaxis does not exist!
a) Sympathomimetics: endogenous catecholamines:
Adrenaline (β1 >> β2 and α1 > α2 agonist) via cAMP
Noradrenaline (α1 > α2 and β1 >> β2 agonist) via cAMP ?
Dose
mcg/kg/min
α1
α2
β1
β2
Clinical effect
– 0.10
+++
++
+++
↑ SVR, HR
(↓) CO
0.10 – 0.20
++++
+++
+++
↑ SVR, HR, SV
↓ CO
Side effects: increasing myocardial oxygen requirement, can cause decrease in CO, tachyphylaxis, hyperglycaemia
Dopamine (D1 and D2, higher doses: β1 >> β2 and α1 > α2 agonist) via cAMP. Precursor of norepinephrine
Dose
mcg/kg/min
α1
α2
β1
β2
Clinical effect
0.5 – 2
↑ increased splanchnic perfusion
2 – 5
++
↑ HR, SV, CO
5 – 10
++
++
↑ HR, SV, SVR
(↓) CO
> 10
+++
↑ SVR
↓ CO
Side effects: increasing myocardial oxygen requirement, can cause decrease in CO, tachyarrhythmias, tachyphylaxis, hyperglycaemia, immunsuppressive effect, inhibition of thyrotropin releasing hormone
Phenylephrine (α1 >> α2 agonist) – resuscitation in Fallot spells
Dose
mcg/kg/min
α1
α2
β1
β2
Clinical effect
0.1 – 5
+++
++
+++
↑ SVR
↓ HR (reflex), CO
Side effects: increasing myocardial oxygen requirement,
can cause decrease in CO, tachyphylaxis, hyperglycaemia
d) Phosphodiestarase inhibitors:
Milrinone via cAMP
Dose
mcg/kg/min
Clinical effect
Load: 50mcg/kg
0.2 – 1
↑ CO (positive inotropic and lusitropic effect)
↓ PVR, (SVR)
Side effects: arrhythmia, hypotension (ensure appropriate volume load)
e) Myofilament calcium sensitisers:
Levosimendan via increasing sensitivity to calcium
Dose
mcg/kg/min
Clinical effect
Load: 1.25mcg/kg
over 10min
Infusion: 0.2
↑ CO (positive inotropic and lusitropic effect)
Side effects: arrhythmia, hypotension in the first hours
f) Vasoregulatory agents:
Vasopressin (V1 – arterial and V2 – tubular agonist)
Dose
IU/kg/hr
V1 & V2
Clinical effect
0.01 – 0.06
+++
↑ SVR
Side effects: increasing myocardial oxygen reqirement, can cause decrease in splanchnic perfusion
References:
[1] Am Heart J 2002 Jan; 143(1) : 15-21: Hoffman TM et al: Prophylactic intravenous use of milrinone after cardiac operation in pediatrics (PRIMACORP) study.
[2] Lancet 2002, 306: 196-202: Follath F et al: Efficacy and Safety of intravenous levosimendan compared with dobutamine in severe low-output heart failure (the LIDO study); a randomised double-blind trial.
[3] Curr Opin Crit Care. 2010 Oct;16(5):432-41: Parissis et al: Inotropes in cardiac patients: update 2011
[4] Curr Opin Anaesthesiol. 2009 Aug;22(4):496-501: Salmenper√§ et al: Levosimendan in perioperative and critical care patients.
[5] Pediatr Cardiol. 2004 Nov-Dec;25(6):623-46: Barnes et al: The pediatric cardiology pharmacopoeia: 2004 update
[6] Pediatr Crit Care Med. 2006 Sep;7(5):445-8: Namachivayam P et al: Early experience with Levosimendan in children with ventricular dysfunction.
[7] N Engl J Med. 2008 Feb 28;358(9):877-87: Russel et al: Vasopressin versus norepinephrine infusion in patients with septic shock
All Marc’s PICU cardiology FOAM can be found on PICU Doctor and can be downloaded as a handy app for free on iPhone or Android. A list of contributors can be seen here.
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Inotropes and vasopressors
Tags: vasopressors
Marc Anders. Inotropes and vasopressors, Don't Forget the Bubbles, 2013. Available at:
https://doi.org/10.31440/DFTB.3876
Definition:
Inotropes: sympathomimetic agent which act on the sympathetic (or adrenergic) nervous system (β-receptors) resulting in positive inotropic (increase in contractility), chronotropic (increase in heart rate), dromotropic (increase in conduction of impulse) and lusitropic effect (improved diastolic relaxation)
Vasopressors: sympathomimetic agent which act on the sympathetic (or noradrenergic) nervous system (α-receptors) resulting in vasoconstrictor effect
The ideal vasoactive support agent: effect on cardiac output/effect on SVR/effect on myocardial oxygen consumption/no tachyphylaxis does not exist!
a) Sympathomimetics: endogenous catecholamines:
Adrenaline (β1 >> β2 and α1 > α2 agonist) via cAMP
Dose
mcg/kg/min
↑ HR, SV, CO
(↓) SVR
↑ HR, SV, SVR
(↓) CO
Noradrenaline (α1 > α2 and β1 >> β2 agonist) via cAMP ?
Dose
mcg/kg/min
↑ SVR, HR
(↓) CO
↑ SVR, HR, SV
↓ CO
Dopamine (D1 and D2, higher doses: β1 >> β2 and α1 > α2 agonist) via cAMP. Precursor of norepinephrine
Dose
mcg/kg/min
↑ HR, SV, SVR
(↓) CO
↑ SVR
↓ CO
b) Sympathomimetics: synthetic catecholamines:
Dobutamine (β1 >> β2)via cAMP
Dose
mcg/kg/min
↑ HR, SV, CO
(↓) SVR
Isoprenaline (β)via cAMP
Dose
mcg/kg/min
c) Sympathomimetics: synthetic noncatecholamines:
Phenylephrine (α1 >> α2 agonist) – resuscitation in Fallot spells
Dose
mcg/kg/min
↑ SVR
↓ HR (reflex), CO
Side effects: increasing myocardial oxygen requirement,
can cause decrease in CO, tachyphylaxis, hyperglycaemia
d) Phosphodiestarase inhibitors:
Milrinone via cAMP
Dose
mcg/kg/min
↑ CO (positive inotropic and lusitropic effect)
↓ PVR, (SVR)
e) Myofilament calcium sensitisers:
Levosimendan via increasing sensitivity to calcium
Dose
mcg/kg/min
Load: 1.25mcg/kg
over 10min
f) Vasoregulatory agents:
Vasopressin (V1 – arterial and V2 – tubular agonist)
Dose
IU/kg/hr
References:
[1] Am Heart J 2002 Jan; 143(1) : 15-21: Hoffman TM et al: Prophylactic intravenous use of milrinone after cardiac operation in pediatrics (PRIMACORP) study. [2] Lancet 2002, 306: 196-202: Follath F et al: Efficacy and Safety of intravenous levosimendan compared with dobutamine in severe low-output heart failure (the LIDO study); a randomised double-blind trial. [3] Curr Opin Crit Care. 2010 Oct;16(5):432-41: Parissis et al: Inotropes in cardiac patients: update 2011 [4] Curr Opin Anaesthesiol. 2009 Aug;22(4):496-501: Salmenper√§ et al: Levosimendan in perioperative and critical care patients. [5] Pediatr Cardiol. 2004 Nov-Dec;25(6):623-46: Barnes et al: The pediatric cardiology pharmacopoeia: 2004 update [6] Pediatr Crit Care Med. 2006 Sep;7(5):445-8: Namachivayam P et al: Early experience with Levosimendan in children with ventricular dysfunction. [7] N Engl J Med. 2008 Feb 28;358(9):877-87: Russel et al: Vasopressin versus norepinephrine infusion in patients with septic shockAll Marc’s PICU cardiology FOAM can be found on PICU Doctor and can be downloaded as a handy app for free on iPhone or Android. A list of contributors can be seen here.
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