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