Push Dose Vasopressors & The Hypotensive Trauma Patient

• Managing the hypotensive patient is an essential skill in the emergency department (ED) as prolonged hypotension can lead to poor clinical outcomes in high-risk patients. 
• Depending on the policies and procedures of your institution, push-dose phenylephrine (PDP-PE) or epinephrine (PDP-E) can resolve transitory hypotension as a temporizing measure. 
• The administration of  push-dose vasopressors requires nursing diligence as they carry inherent risks, including miscalculations of dilution, dose calculations errors, push-dose administration errors, reliance on verbal orders and overriding medication safety checks during emergency use. 

What Are Push Dose Vasopressors?

As an emergency room nurse, transporting a trauma patient with a labile blood pressure can be tenuous. If the patient develops significant hypotension, dysrhythmias, or cardiac arrest, what life-saving tools do you have in your toolbox? Managing the hypotensive patient is an essential skill in the emergency department (ED) as prolonged hypotension can lead to poor clinical outcomes in high-risk patients. 

A rapid bolus of crystalloid fluids, either non-balanced 0.9% normal saline (NS) or balanced sodium lactate (LR), even when administered via pressure bag, requires time to produce a notable effect on hypotension. Depending on the policies and procedures of your institution, push-dose phenylephrine (PDP-PE) or epinephrine (PDP-E) can resolve transitory hypotension as a temporizing measure. Both drugs are safe to use in peripheral lines and are not complex to mix, but they can be prone to dosing errors.  

The administration of  push-dose vasopressors requires nursing diligence as they carry inherent risks, including miscalculations of dilution, dose calculations errors, push-dose administration errors, reliance on verbal orders and overriding medication safety checks during emergency use.  

What is a push-dose pressor (PDP)? Push-dose vasopressors are small intravenous bolus doses (pushes) administered to hypotensive patients to increase cardiac output and brain perfusion. In the emergency room, the most common push-dose pressors are phenylephrine and epinephrine.  

The indications for PDP are based on the urgent reversal of hypotension. Both phenylephrine and epinephrine are temporary measures to increase the perfusion of vital organs, and neither replaces proper resuscitation efforts.  

Important indications on epinephrine. Epinephrine is the preferred drug over phenylephrine in patients with cardiogenic shock because phenylephrine may decrease cardiac output secondary to the potential for reflexive bradycardia.  

Push-dose vasopressors in trauma patients is an accepted clinical practice. It is important that their reliance does not mask inadequate fluid resuscitation. 

Phenylephrine (PDP-PE)

Phenylephrine HCL (Neo-Synephrine) Phenyl-stick, Neo-stick, is a short half-life, pure alpha-adrenergic receptor agonist. As a push-dose vasopressor, phenylephrine causes an increase in coronary perfusion via arterial vasoconstriction without a direct effect on the patient’s heart rate. 

Phenylephrine, as a push-dose pressor, is ideal in the PDD in the patient with tachycardia, because it will not increase the patient’s heart rate. Phenylephrine’s onset is less than one minute. Duration can last up to twenty minutes.

In various institutions, phenylephrine is available in pre-packaged syringes. For this reason, push-dose phenylephrine is the preferred drug to epinephrine for rapid administration when available as a pre-packaged medication.

The best-case use; the hypotensive trauma patient with tachycardia. In the hypotensive patient, re-dosing of phenylephrine can occur every two-five minutes. Titrated to effect. 

Epinephrine (PDP-E)

Epinephrine, an inopressor, increases cardiac contractility and peripheral vasoconstriction. With a longer half-life and potential cardiac complications, epinephrine may be the best-use (second choice) push-dose pressor for the hypotensive trauma patient.  

Important warning: do not administer cardiac arrest doses (1 mg) to patients with a pulse. Best practice is to avoid pushing epinephrine when drawn from a cardiac ampule. The onset is less than one minute, and a single dose may last ten minutes. In most cases, the effects of epinephrine dissipate within five minutes. Best case use, the hypotensive patient without tachycardia.

Push Dose Vassopressors Mixing Instructions

Epinephrine

• Use a 10-ml syringe with 9 ml normal saline  
• In the syringe, draw up 1 ml of epinephrine from the cardiac amp (An ampule of cardiac epinephrine has 100mcg/ml) 
• Mixture equates to 10mls of epinephrine at 10 mcg/ml  
• Onset 1 minute 
• Duration 5-10 minutes 
• Dose 0.5 ml-2ml every 2-5 minutes (5-20 mcg) 

Phenylephrine

• Use a 3-ml syringe and draw up 1 ml of phenylephrine from the vial (vial contains phenylephrine 10 mg/ml)  
• Inject into a 100ml bag of NS 
• The bag has 100mls of phenylephrine at 100 mcg/ml  
• In the bag each ml in the syringe has 100 mcg/ml of phenylephrine  
• Onset 1 min  
• Duration 10-20 minutes 
• Dose 0.5-2 ml every 2-5 minutes (50-200 mcg)  

The Bottom Line on Push Dose Vassopressors

Phenylephrine at 100 mcg/mL has a higher target concentration than epinephrine at 10 mcg/mL and a higher dose-per-push than epinephrine at 50-200 mcg. Phenylephrine has a longer duration at 10-20 min vs. 5-10 min for epinephrine. Check with your emergency department policies and pharmacy to see the administration standards for your organization. Phenylephrine and epinephrine administration require extreme caution to avoid medication errors and potential patient harm. 

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