Catherine Jamin, Associate professor of Emergency Medicine at NYU Langone Health, talks about the essential use of vasopressors in the ED to increase blood pressure, improve organ function, and optimize metabolic status. She discusses the commonly used vasopressors, their mechanisms, dosages, and situational preferences. The podcast also covers the diagnosis of underlying pathology, the use of vasopressin and phenylephrine, and the escalation strategy for refractory shock.
Norepinephrine is the primary vasopressor for most types of shock, with vasopressin as a common adjunct.
Phenylephrine and epinephrine are utilized in specific clinical scenarios.
Peripheral pressors are a safe and effective option for prompt perfusion, while push-dose pressors offer rapid blood pressure support in critical situations.
Deep dives
Norepinephrine: A Versatile Vasopressor for Different Types of Shock
Norepinephrine is the go-to vasopressor for various types of shock, including septic shock, undifferentiated shock, and hypovolemic shock. It works by increasing vascular resistance and cardiac output. The starting dose is typically 10 mics per minute and can be titrated to achieve a mean arterial pressure (MAP) greater than 65. Norepinephrine is preferred due to its multiple mechanisms of action and peripheral administration capability.
Vasopressin: An Adjunctive Vasopressor for Septic Shock
Vasopressin is commonly used as a second-line vasopressor in septic shock, typically added to norepinephrine. It acts primarily through vasoconstriction by activating V1A receptors. The standard dose for vasopressin is 0.04 units per minute, and it is not titratable. Its major benefit is reducing norepinephrine requirements. Although adverse effects may occur, they are difficult to distinguish from the underlying patient pathology.
Phenylephrine and Epinephrine: Vasopressors for Specific Situations
Phenylephrine stimulates alpha-1 receptors, making it suitable for patients with high cardiac output states, hypotension with tachyarrhythmias, and critical aortic stenosis. It is also used during peri-intubation and in sedated patients with hypotension. However, caution is advised as it may worsen low cardiac output states. Epinephrine stimulates multiple receptors, resulting in vasoconstriction and increased cardiac output. It is the choice for anaphylactic shock and second or third line for septic shock. Starting dose ranges from 5 to 10 mics per minute, targeting a MAP greater than 65.
Peripheral Pressors: Safe and Convenient Option for Prompt Perfusion
Peripheral pressors, such as norepinephrine, can be safely administered through large-bore peripheral IVs in proximal veins. Studies have shown low incidence of adverse events. The ability to give peripheral pressors promptly restores perfusion and blood flow to organs, but careful monitoring is critical to detect extravasation. Norepinephrine can be initiated peripherally, and if escalating doses are required or the patient is critically ill, central access can be established.
Push-Dose Pressors: Rapid Blood Pressure Support in Critical Situations
Push-dose pressors are used in peri-intubation or peri-code situations where a rapid increase in blood pressure is necessary. Phenylephrine is commonly used as a push dose, while epinephrine may be considered for patients with increased afterload. These medications provide a bridge to stabilize the patient while other vasopressor infusions are initiated.
Conclusion
In summary, norepinephrine is the primary vasopressor for most types of shock, with vasopressin as a common adjunct. Phenylephrine and epinephrine are utilized in specific clinical scenarios. Peripheral pressors are a safe and effective option for prompt perfusion, while push-dose pressors offer rapid blood pressure support in critical situations.
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 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/
