Use of Push-Dose Pressors in the Resuscitation of the Critically Ill

Educational Objectives

The goal of this program is to improve the use of push-dose pressors in the emergency department. After hearing and assimilating this program, the clinician will be better able to:

1. Optimize use of push-dose pressors.
2. Use vasopressin in a patient with severe acidemia.

Summary

Push-dose pressors: should not be used when a patient requires resuscitation before intubation, where blood pressure stabilization and a continuous vasopressor, eg, norepinephrine or vasopressin, are necessary, followed by positive-pressure ventilation after intubation; using push-dose pressors in this situation leads to the patient coding; however, push-dose pressors are useful for anticipated transient hypotension (eg, administering phenylephrine alongside propofol for sedation in elderly patients), bridging to a continuous vasopressor in patient with known hypotension (eg, using push-dose phenylephrine while waiting for norepinephrine to be prepared), and in unanticipated hypotension (eg, quickly accessing a push dose presser from a code cart in an emergency); receptors — α-1 causes vasoconstriction; β-1 causes ionotropy and chronotropy; β-2 causes smooth muscle relaxation; V1 causes vasoconstriction

Phenylephrine: is a pure α-1 agonist that causes vasoconstriction without affecting heart rate or contractility; continuous infusion — is dosed at 10 to 300 μg/min; push doses — are 50 to 200 μg every several minutes; it is ideal for treating hypotension because of vasodilation (eg, atrial fibrillation with rapid ventricular response), although it may induce reflex bradycardia by increasing afterload

Epinephrine: acts on β-1, β-2, and α-1 receptors; continuous infusion — is dosed at 2 to 20 μg/min; push doses — are 10 μg every few minutes; because of its ionotropic effect, it is more suitable for treating hypotension caused by impaired cardiac output; it is also useful in emergency situations, as it is readily available in code carts; however, because of its β-1 effects, the risk for tachydysrhythmias is increased

Key points about push doses: the dose is equivalent to that of a moderate-rate infusion, but it is administered as a bolus every few minutes until blood pressure responds

Preparing pressors at the bedside: phenylephrine — a common preparation involves diluting a 10-mg vial in a 100-mL bag of normal saline (final concentration of 100 μg/mL); however, performing these calculations under pressure can be challenging, so premixing and proper labeling are essential to avoid errors; different concentrations of phenylephrine (eg, 100 μg/10 mL or 400 μg/10 mL) can lead to errors if not verified carefully; dilution errors are the most common, followed by communication errors; in high-stress situations, it is easy to miscalculate doses by an order of magnitude or miscommunicate instructions, eg, requesting an epinephrine infusion might be misinterpreted as a push dose, or asking for “50 of phenylephrine” could lead to confusion if the physician means 50 μg and the nurse assumes 50 mg; additionally, peripheral pressors carry risks, eg, extravasation and adverse effects; to minimize errors, use premade syringes whenever possible and collaborate with site leadership and pharmacy teams to eliminate sources of error; ephinephrine — the code-dose concentration is 1 mg/10 mL, with each 1 mL containing 100 μg; take a 10-mL flush and waste 1 mL, leaving 9 mL; draw up 1 mL of epinephrine; the new preparation contains 10 μg in 1 mL; use 1 mL every several minutes; to avoid errors, use pre-made syringes whenever possible

Advanced push-dose pressors: ephedrine is an indirect vasopressor that increases norepinephrine release and inhibits its reuptake; because it relies on endogenous norephinephrine, it is less effective in patients with prolonged shock; it provides predominantly α effects with some β-1 and very little β-2; it is not given as a continuous infusion; the push dose is 5 to 10 mg; it has a long duration of action (≤1 hr), which predisposes it to tachyphylaxis, limiting its utility in emergency settings; norepinephrine (Levophed) provides strong α-1 vasoconstriction along with some β effects, offering both inotropic and chronotropic support; continuous infusion is dosed at 2 to 30 μg/min; the push dose is 5 to 10 μg every several minutes; it has the most rapid onset and shortest duration of all push-dose pressors, with a lower risk of causing tachycardia; evidence for its role as a push-dose pressor is still emerging, but it is expected to become more common in emergency care

Vasopressin: is commonly used in septic shock and can also be administered as a bolus; its action on V1 receptors provides vasoconstriction (similar to phenylephrine) but is more pH-independent than catecholamines, making it especially useful for patients with severe acidemia; at lower doses, it can cause pulmonary artery vasodilation, making it a potential option for patients with right heart failure or pulmonary embolism; continuous infusion — is given at 0.01 to 0.04 units/min; push doses — are 0.4 to 2 units (often simplified to 1 unit); although its use in the emergency department is mainly supported by case reports, it is more commonly used as a bolus in anesthesiology practice

Readings

Cole JB, Knack SK, Karl ER, et al. Human errors and adverse hemodynamic events related to “Push Dose Pressors” in the Emergency Department. J Med Toxicol. 2019;15(4):276-86. doi:10.1007/s13181-019-00716-z; Morley H, Seabury R, Parsels K, et al. Preparation/administration of push-dose versus continuous infusion epinephrine and phenylephrine: a simulation. Am J Emerg Med. 2023;74:135-39. doi:10.1016/j.ajem.2023.10.002; Rotando A, Picard L, Delibert S, et al. Push dose pressors: experience in critically ill patients outside of the operating room. Am J Emerg Med. 2019;37(3):494-98. doi:10.1016/j.ajem.2018.12.001; Sacha GL, Bauer SR. optimizing vasopressin use and initiation timing in septic shock: a narrative review. Chest. 2023;164(5):1216-27. doi:10.1016/j.chest.2023.07.009; Singer S, Pope H, Fuller BM, et al. The safety and efficacy of push dose vasopressors in critically ill adults. Am J Emerg Med. 2022;61:137-42. doi:10.1016/j.ajem.2022.08.055.

Disclosures

For this program, members of the faculty and the planning committee reported nothing relevant to disclose.

Acknowledgements

Dr. Jansson was recorded at the 2024 Rocky Mountain Winter Conference, held February 24-28, 2024, in Steamboat Springs, CO, and presented by EMedHome.com. For information about upcoming CME activities from this presenter, please visit https://Emedhome.com. Audio Digest thanks the speakers and presenters for their cooperation in the production of this program.

CME/CE INFO

Accreditation:

The Audio- Digest Foundation is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians.

The Audio- Digest Foundation designates this enduring material for a maximum of 0.75 AMA PRA Category 1 Credits™. Physicians should claim only the credit commensurate with the extent of their participation in the activity.

Audio Digest Foundation is accredited as a provider of continuing nursing education by the American Nurses Credentialing Center's (ANCC's) Commission on Accreditation. Audio Digest Foundation designates this activity for 0.75 CE contact hours.

Lecture ID:

EM420901

Expiration:

This CME course qualifies for AMA PRA Category 1 Credits™ for 3 years from the date of publication.

Instructions:

To earn CME/CE credit for this course, you must complete all the following components in the order recommended: (1) Review introductory course content, including Educational Objectives and Faculty/Planner Disclosures; (2) Listen to the audio program and review accompanying learning materials; (3) Complete posttest (only after completing Step 2) and earn a passing score of at least 80%. Taking the course Pretest and completing the Evaluation Survey are strongly recommended (but not mandatory) components of completing this CME/CE course.

Estimated time to complete this CME/CE course:

Approximately 2x the length of the recorded lecture to account for time spent studying accompanying learning materials and completing tests.

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