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:
1. Increasing systemic vascular resistance via vasoconstriction
2. 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

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

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

Escalation Strategy in Refractory Shock

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

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 situation because it is going to be one of the fastest ways we can boost BP while we work on other measures to stabilize the patient

Additional References

Importance of RUSH (Rapid Ultrasound in SHock) exam for diagnosis and treatment planning: https://emcrit.org/rush-exam/

Episode 188: Vasopressors