What is the difference between epinephrine and phenylephrine

This risk-aversion may be pushing us to insert more central lines, thereby actually increasing the risk that our patients are exposed to 7. Epinephrine and phenylephrine aren't the most popular drugs, but they can get you pretty far especially in combination 8. Epinephrine is supported by two RCTs for potential use as a front-line vasopressor in septic shock Myburgh , Annane Imagine a patient with mild urosepsis who doesn't respond to fluid resuscitation and needs a bit of vasopressor support.

A reasonable approach to this patient could be to trial them on a low-dose peripheral epinephrine infusion. If the patient responds well, this could be continued until shock resolves 9. Previously isoproterenol was my treatment for mild symptomatic bradycardia in a patient without central access, because it has minimal extravasation risk. Peripheral epinephrine is an effective alternative. Traditionally, phenylephrine has been frowned upon in critical care due to concerns that it could reduce cardiac output and organ perfusion.

However, most evidence suggests that phenylephrine may function very similarly to norepinephrine. Both drugs may cause venoconstriction, increasing preload and potentially increasing cardiac output more on this here Traditional wisdom was that all patients on a vasopressor for more than a few hours require a central line. This has been disproven by Cardenas-Garcia , Delgado , and Putland However, there still isn't enough evidence to reach a universal answer.

Thus, it may be best to make this judgment on a patient-by-patient basis, weighing the following factors:. As with most critical care conundrums, there is no simple answer. Make your best judgment call, follow the patient carefully, and adjust strategy as appropriate. When in doubt, it may be reasonable to continue peripheral vasopressors, because many patients will improve and only require vasopressor transiently Image credits: Homeopathic dilution ,.

I have been writing a protocol for the use of peripheral Norad in remote settings. And the big advantage they have is that they allow us to institute good care early in septic patients. This is a winner for all those patients Casey. Thanks, Casey. However, even in highly-resourced hospitals, I think the delay to vasopressors and over-use of fluid loading remains a problem. Good luck with your protocol, would be great if you could collect some data and publish it either medical literature or your site.

The precise safety of norepinephrine remains unclear to me. I secretly believe that the manufacturers might have increased the pH of norepinephrine over the last few decades, making it safer than it used … Read more ». Thanks, Pierre. I agree with you, but at the same time I wish there was more evidence supporting the safety of peripheral norepinephrine infusions.

Hopefully some more studies will be released over the next few years describing peripheral norepinephrine, ideally containing large numbers of extravasation events i. Part of this is also center-dependent, related to exactly how reliable IV checks are and how rapidly the pharmacy can mobilize antidotes.

I have some reservations about relying heavily on nursing and pharmacy to salvage patients from extravasation reactions. Although generally effective, this … Read more ».

Fair points all — perhaps I am overly optimistic that we can recognize and treat extravasation efficiently to prevent necrosis — one thing we have at our center is pharmacists in the ICU, they are really a huge resource and can efficiently get whatever we need, especially an antidote — but this is certainly not the case for all centers so your concerns are appropriate..

However, note that, in the Cardenas paper, of the 19 total extravasations reported, 16 of them were norepinephrine — and all successfully treated with antidote — this is a fair number of norepinephrine extravasations … Read more ».

What initially motivated me to look into this topic is that part of my job is to help write ICU protocols for a community hospital affiliated with Genius General Hospital. Phenylephrine and epinephrine may be especially helpful in a community hospital setting where resources such as a dedicated hr ICU pharmacist are less abundant. However, I think the concept of safer vasopressors can still be useful in even the largest and best resourced hospital.

You can ask for an epinephrine drip without worrying about … Read more ». We have completed a study on utilizing phenylephrine through peripherals at Wake Forest and will be presenting the abstract at the Neurocritical Care Society meeting this week.

Not to mention we inject phenylephrine directly into the penis for the treatment of priapism and I have yet to see that cause a complication. Hi Josh, Awesome post. I am attempting to find guidelines for when to significantly suggest an ART line for interfacility transports or when to refuse to transport unless an A-line is placed. I work for a Critical Care Ground Transport Services that functions at all levels and all types of calls , nursing home, discharges, interfacility at all levels etc.

My question is how many vasoactive agents can be running before you really push to have arterial invasive blood pressure monitoring. Obviously the more peripheral vasoconstriction we cause with medication the more inaccurate the NIBP gets.

Or is there a … Read more ». We are the EMCrit Project , a team of independent medical bloggers and podcasters joined together by our common love of cutting-edge care, iconoclastic ramblings, and FOAM. Concentrated epinephrine and phenylephrine are safe for subcutaneous use At Genius General Hospital , our epinephrine infusion is mixed in the pharmacy by combining 4 ml of epinephrine with ml of D5W. Micromedex and Epocrates still recommend subcutaneous phenylephrine to prevent hypotension during anesthesia: Why might peripheral epinephrine and phenylephrine be safe?

Epinephrine functions as its own antidote Epinephrine has a unique dual effect on skin arteries which may explain its unusual safety profile: Epinephrine stimulates alpha-receptors, causing dermal artery vasoconstriction that promotes ischemia and skin necrosis.

Epinephrine also stimulates beta-2 receptors, causing dermal artery vasodilation. Recent data from Rehberg et al. Nevertheless, our model mimics a frequent clinical situation late peritonitis and is clearly associated with vascular and myocardial dysfunction and certainly appears to be suitable for mechanistic studies.

Finally, the study was limited to the short-term effects of treatments and this timing did not take into account other effects of catecholamines such as immune effects.

Load—sensitive and load-independent myocardial parameters measured alternatively with conductance catheter or micro-PET were similarly modified under vasopressor treatment. This may be important, especially in situations in which hemodynamic monitoring is limited such as in the emergency or operating room. Conversely, epinephrine and norepinephrine improved global hemodynamics and myocardial function in severely hypokinetic and hypotensive experimental septic shock.

Nevertheless, epinephrine was associated with increased myocardial oxygen consumption without altering heart structure, myocardial perfusion, and myocardial energetics. Therefore, norepinephrine thus appears to be a more reliable and safe strategy as a first-line therapy in this particular setting. Sign In or Create an Account. Advanced Search. Sign In. Skip Nav Destination Article Navigation. Close mobile search navigation Article navigation. Volume , Issue 5. Previous Article Next Article.

Materials and Methods. Article Navigation. Critical Care Medicine May This Site. Google Scholar. Antoine Kimmoun, M. Anna Furmaniuk, M. Zerin Hekalo, M. Fatiha Maskali, Ph. Sylvain Poussier, Ph. Pierre-Yves Marie, M. Bruno Levy, M.

Anesthesiology May , Vol. Get Permissions. Myocardial dysfunction occurs during septic shock. View large. View Large. View large Download slide. Lancet ; — Intensive Care Med ; — Circulation ; — Shock ; 30 Suppl 1 —7. Hollenberg SM: Vasoactive drugs in circulatory shock. A forensic cardio-pathologist point of view. Forensic Sci Int ; —8. Cardiovasc Toxicol ; — Myburgh JA: Catecholamines for shock: The quest for high-quality evidence. Crit Care Resusc ; —6. Crit Care ; Eur Heart J ; — J Pharmacol Exp Ther ; — E-mail : bhuvaneswari.

The first question for an anesthesiologist is to figure out what is responsible for the hypotension, vascular tone may be reflected in values of vascular resistance R or CO. For the purpose of this article we assume that the process of differential diagnosis led to the conclusion that the hypotension resulted from vasodilation and administration of a vasopressor in this order.

What are the physiological effects of the two drugs in question? Therefore, it is not surprising that constriction of veins develops earlier, at smaller doses and to a greater degree than of arteries. Constriction of arterioles results in a decrease in flow through them and tissues fed by those arteries. Constriction of veins, particularly compliant veins i. Constriction of that vasculature decreases flow through the splanchnic organs and tissues, and sequesters blood upstream, decreasing the VR and CO [3].

Actually, an increase in arterial pressure after injection of PE results from an increase in arterial tone by one third and by two thirds from an increase in VR [4]. Such a complexity leads to contradictions: It has been demonstrated that PE may increase or decrease CO [5]. Some patients show a decrease in CO during PE infusion. Dogs were given phenylephrine or epinephrine at nine minutes and defibrillation was attempted at 12 minutes.

Dogs underwent hemodynamic monitoring and pharmacologic support, if necessary, for an additional 90 minutes. At four, eight, 12, and 24 hours, a standard neurologic examination was performed and deficit scores were assigned by an observer blinded to the drug given.