Episode 188: Vasopressors

We go over the essential and complex topic of vasopressors in the ED.

Hosts:

Brian Gilberti, MD

Catherine Jamin, MD

https://media.blubrry.com/coreem/content.blubrry.com/coreem/Vasopressors.mp3

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Tags: Critical Care

Show Notes

Introduction

Host: Brian Gilberti, MD

Guest: Catherine Jamin, MD

Associate professor of Emergency Medicine at NYU Langone Health

Vice Chair of Operations

Triple-boarded in Emergency Medicine, Internal Medicine, and Critical Care Medicine

Topic: Vasopressors: Essential agents for supporting critically ill patients in the ED

What Are Vasopressors and When to Use Them

Two primary mechanisms to increase blood pressure:

Increasing systemic vascular resistance via vasoconstriction

Increasing cardiac output via augmenting inotropy and chronotropy

Indicators for vasopressor use:

MAP <65, systolic BP <90, or significant drop from baseline BP

Signs of organ dysfunction like altered mental status, decreased urine output, elevated lactate

Fluid resuscitation either ineffective or contraindicated (e.g., in CHF patients)

Commonly Used Vasopressors in the ED

Norepinephrine

Epinephrine

Vasopressin

Phenylephrine

Norepinephrine

Mechanism: Stimulates alpha-1 (vasoconstriction) and beta-1 receptors (increases inotropy & chronotropy)

Starting Dose: 10 mcg/min, titrate to MAP >65

Max Dose: No strict limit but usually add a 2nd pressor at 15-20 mcg/min

Situational Preference: First-line for most cases of shock (septic, undifferentiated, hypovolemic, cardiogenic)

Pros: Can be infused peripherally via large bore IV

Vasopressin

Mechanism: Activates V1a receptors causing vasoconstriction

Dose: Fixed, non-titratable dose of 0.04 units/min

Situational Preference: Second-line in septic shock

Concerns: Potential for peripheral ischemia

Phenylephrine

Mechanism: Stimulates alpha-1 receptors causing vasoconstriction

Starting Dose: 100 mcg/min, titrate to MAP >65

Situational Preference: High cardiac output states, tachyarrhythmias, peri-intubation

Concerns: Increases afterload, can worsen low cardiac output states

Epinephrine

Mechanism: Stimulates alpha-1, beta-1 and beta-2 receptors

Starting Dose: 5-10 mcg/min, titrate to MAP >65

Situational Preference: Anaphylactic shock, septic cardiomyopathy

Limitations: Can induce tachycardia, may elevate lactate levels

Escalation Strategy in Refractory Shock

Norepinephrine -> Vasopressin (with stress dose steroids) -> Epinephrine

Consider POCUS, lactate, central venous saturation, and acid-base status

Peripheral Pressors

Can safely be administered peripherally via large bore IVs in proximal upper extremity

Sites: Cephalic or basilic veins

Adverse Events: Low at 1.8% based on meta-analysis

Actions in case of extravasation: Phentolamine injection, nitroglycerin paste

Push-Dose Pressors

Primarily Phenylephrine (peri-intubation, during procedures)

Also Epinephrine for peri-code situations

Doses: Epi – 5-20 mcg every 2-5 min

Take-Home Points

Most used medications are going to be norepinephrine, vasopressin, phenylephrine, and epinephrine.

Consider these medications if there are signs of end-organ dysfunction, there is a considerable delta in baseline BP, systolic is less than 90 and/or MAP is less than 65

Norepinephrine is a good pressor for a lot of the situations that we encounter in the emergency department, such as septic shock, undifferentiated shock and hypovolemic shock.

Vasopressin is commonly the second we reach for in most of these scenarios

Epinephrine will be first for anaphylactic shock and may be the third agent in septic shock

Think about phenylephrine in high-output states (patients with tachydysrhythmias), or with AS, though be cautious in patient with low cardiac output

The benefits outweigh risks for peripheral pressors in situations where you promptly have to increase blood pressure while you work on central access

Push-dose pressures can help you in a peritinbatuion or pericode situat