| Dopamine |
Mechanism of Action
Dopamine hydrochloride is a sympathomimetic chemical
precursor to norepinephrine. It has differing effects on the
vascular and cardiac systems, depending on dose per kilogram
per minute. Because of the variability in the response to
dopamine, this drug must be monitored and titrated to effect.
In lower doses (1 to 2 mcg/kg/min), it stimulates dopaminergic
receptors dilating renal,cerebral and mesenteric vasculature,
maintaining blood flow.
In the middle ranges (2 to 10 mcg/kg/min), the B-adrenergic and
A-adrenergic receptors are stimulated. This produces enhanced
cardiac output and marked increases in systemic vascular
resistance and pulmonary vascular resistance. The end result is
a stronger heart beating against stronger preload.
In the higher ranges (20 mcg/kg/min), dopamine has the
hemodynamic effects of norepinephrine. This causes wide
systemic vasoconstriction, usually constricting the mesenteric
arteries. This can shut off blood flow to the mesenteries, causing
tissue death.
Indications
Cardiogenic shock
Significant hypotension in the absence of hypovolemia
Packaging
400 mg in 250 ml of D5W (pre-pack) producing a concentration
of 1600 mcg/ml
Drug box inventory = 1
Onset & Duration
Onset: 1-3 hours for maximum effect.
Duration: 6-12 hours
Doses and Administration
5 mcg/kg/min IV drip
With a concentration of 1600 mcg/ml and mini-drip (60 gtt/ml)
tubing you can use a chart to calculate doses:
Steps to calculate proper doses:
Estimate the patients weight.
Input weight into formula, ie 5 mcg/kg/min to get desired dose.
Input desired dose into chart for approximate drip rate.
Using the factor that there is 25 mcg per drop, calculate the
precise drip rate for the patient.
Set drip rate, and monitor patient's BP for titration.
Precautions
Will increase heart rate and myocardial oxygen demands
Can cause supraventricular and ventricular arrhythmias
Can worsen pulmonary congestion
Tissue necrosis will occur if extravasation occurs
Pediatrics
Rarely recommended, not used in the GMVEMSC protocols
Dopamine hydrochloride is a sympathomimetic chemical
precursor to norepinephrine. It has differing effects on the
vascular and cardiac systems, depending on dose per kilogram
per minute. Because of the variability in the response to
dopamine, this drug must be monitored and titrated to effect.
In lower doses (1 to 2 mcg/kg/min), it stimulates dopaminergic
receptors dilating renal,cerebral and mesenteric vasculature,
maintaining blood flow.
In the middle ranges (2 to 10 mcg/kg/min), the B-adrenergic and
A-adrenergic receptors are stimulated. This produces enhanced
cardiac output and marked increases in systemic vascular
resistance and pulmonary vascular resistance. The end result is
a stronger heart beating against stronger preload.
In the higher ranges (20 mcg/kg/min), dopamine has the
hemodynamic effects of norepinephrine. This causes wide
systemic vasoconstriction, usually constricting the mesenteric
arteries. This can shut off blood flow to the mesenteries, causing
tissue death.
Indications
Cardiogenic shock
Significant hypotension in the absence of hypovolemia
Packaging
400 mg in 250 ml of D5W (pre-pack) producing a concentration
of 1600 mcg/ml
Drug box inventory = 1
Onset & Duration
Onset: 1-3 hours for maximum effect.
Duration: 6-12 hours
Doses and Administration
5 mcg/kg/min IV drip
With a concentration of 1600 mcg/ml and mini-drip (60 gtt/ml)
tubing you can use a chart to calculate doses:
Steps to calculate proper doses:
Estimate the patients weight.
Input weight into formula, ie 5 mcg/kg/min to get desired dose.
Input desired dose into chart for approximate drip rate.
Using the factor that there is 25 mcg per drop, calculate the
precise drip rate for the patient.
Set drip rate, and monitor patient's BP for titration.
Precautions
Will increase heart rate and myocardial oxygen demands
Can cause supraventricular and ventricular arrhythmias
Can worsen pulmonary congestion
Tissue necrosis will occur if extravasation occurs
Pediatrics
Rarely recommended, not used in the GMVEMSC protocols
