What's the difference?????
- 0Nov 30, '01 by VickyRN Senior ModeratorCan anyone please tell me the difference between dopamine, dobutamine, levophed, epinephrine, and neosynephrine? Know that dopamine has renal action up to 2mcg's; above that stimulates beta-1 and alpha-adrenergic receptors (positive inotropic and chronotropic effects); dobutamine is a pure beta-1 agonist (inotrope with mild chronotropic effects); levophed (norepinephrine) is a potent alpha-receptor agonist causing peripheral vasoconstriction, with minimal effect on beta receptors, and a positive inotrope (dilates coronary arteries), while at the same time increases myocardial oxygen demand and may therefore decrease cardiac output; epinephrine has both alpha and beta adrenergic activity (increases systemic vascular resistance, B/P, and heart rate); and neosynephrine is an alpha agonist, useful in septic shock. Please, please, please, all you experienced critical care nurses, relate your own perceptions and experiences with these drugs. Differences that just aren't found in the drug book. THANKS!!!!!
- 1Nov 30, '01 by hoolahanAsk an easy question why don't ya!
I'll try my best to give you a brief answer, cause dinner's almost ready
It sounds like you already have it down. Maybe you are trying to figure out when you would choose one over another?
For me that would depend on the hemodynamic parameters, and not all pt's have swans.
Basically, we leave levophed as a last resort, though I know in other units they do not. This drug is more commonly known as "Levophed leave 'em dead," for that reason. If we put someone on levophed, it is unlikely that they will survive, since everything else has been tried. I have seen powerful alpha effects of this drug in the form of black shriveled up toes.
Norepi, or Neo, some of our docs swear it constricts the renal arteries too much as contributes to renal failure. This is the drug we usually use in septic shock, since in septic shock, originally there is too much vasodilation, and the neo helps this nicely. We also keep neo in syringes @ a conc of 1cc=100mcg to use in codes, or BP crashes post op open heart.
Dopa, is becoming not as popular around here, and if immediate response isn't seen in CO, it is reduced to renal, and another drug is tried, usually dobutamine. You have to be careful useing dobut if low BP. I have seen neo added to the dopa dobut combo to maintain the BP. But I am not sure I agree with that, I think maybe dobut is not the correct choice then, but some docs like this. It doesn't hurt, but it seems like overkill to me.
Epi, I have seen mostly in peds, or in adults as the drug used before levophed if needed in drip form. Of course it is a great drug for codes. I have seen many pt's need insulin drip if on epi drip for any period of time, even if not diabetic, since the epi stimulates gluconeogenesis, and blood sugars get wacky. Of course pt's will also become extremely tachy on epi, and it is very arrhythmagenic.
OK, I guess that's it for me. I am working very little in the cardiac unit these days, so hope that helps.
- 0Dec 1, '01 by mattcastensGood question!
Since the population I work with is almost purely cardiac (both medical and surgical), this is what I've found:
I love phenylephrine (Neo-Synephrine)! We have found this is the perfect drug post-surgery for patients with low SVR. Usually they don't need to be on it for too long because as their vasculature tightens up over the post-op period, we can wean it off very easily (short half-life). We use it mostly on the younger men who seem to dilate out after bypass. Now, of course, not every patient has a PA catheter, but a handy way to tell the SVR is low without a cardiac output is to look at the diastolic pressure relative to baseline. It's not what I would call a balls-on method of determination, but it helps in a pinch.
I'm not such a big fan of epinephrine unless my patient needs purely inotropic support -- and even then I'd rather go with dopamine. Our surgeons seem to love it, though. I find it's fine to use up to about 1.5 mcg/min. Anything higher than that and I feel that the effects on the heart rate and O2 consumption are just too great. If you're trying to use epinephrine for vasoconstriction, do so only in an emergency and switch to something more efficient as soon as possible (Neo.).
Dopamine is a fine drug, and because it's so flexible with dosing, you can do plenty with it. Great for inotropic support, great for less-intense vasoconstriction, and great for renal perfusion. Aparently there's been some discussion over whether or not there really is a "renal dose", but I figure that I see better urine output at lower doses, so it must work. Remember that as with any drug, different people have different sensitivities. I once had a patient who's blood pressure jumped 20 points on just 2mcg/kg/min! The doc said that it was impossible, that she was just on a "renal dose", so I had him turn off the drip to see for himself. The look on his face was priceless! (>sigh!< Residents. ) Dopamine can be used very well with nitroprusside (Nipride) in those cases when you need inotropic support along with decreased SVR, but in that case, why not use....
Dobutamine. Dobutamine is also a fine drug. Wonderful for inotropic support. However, unlike dopamine, it vasodilates, instead of vasoconstricts. Dobutamine should not be used on people who have low SVR and need inotropic support! Dopamine and dobutamine are a great combination in cardiogenic shock.
As (I think) the case is in most units, in ours norepinephrine (Levophed) is used as a last resort. Because it's such a powerful alpha-agonist it's great for septic shock when the SVR isn't responding to dopamine or phenylephrine. In fact, I've never used it on a cardiac patient. Only septic, renal, or septic-renal patients get the pleasure of "Leave-em-dead". I will say, though, that on the septic patients at least, it really helps pull them through the swamp until the toxins start clearing the system.
I hope this all helps!