Goals on Initiation
Reverse shock and increase tissue perfusion:
- Improve blood flow
- BP (MAP >65) perfuse coronaries and brain
- Mental status
- End tidal CO2
- Maybe: urine output (if Foley present) & capillary refill time
- Increase venous return
- Avoid ischemia & other adverse events
Which vasopressor do I choose? It depends.
For the prehospital provider, most of these are not an option. However, having one pressor that you’re familiar with that can be implemented safely and rapidly is probably more beneficial to the patient than not using a pressor at all, or worse, using it incorrectly.
Currently, norepinephrine is recommended as first line in the vast majority of shock states. However, this is only commercially available in a vial as a concentrated solution, requiring drip preparation.
Most EMS Providers in our area are either more familiar with dopamine or have it as their only option per Protocol. This is likely due to it being a commercially available pre-mixed drip. In short term, may be fine, but is more arrhythmogenic than norepinephrine.
Alternatively, “Dirty” Epi is an option:
- 1 mg into a 1,000 mL NS (conc 1 mcg/mL).
- Maximum rate of infusion will vary with catheter size, IV bag height, and squeeze on the bag; however, with a wide-open 18-gauge IV, the patient will receive about 20-30 mL/min (or 20-30 mcg/min) of epinephrine, which is similar to the recommended push-dose epi (0.1 mg or 100 mcg over 5 minutes = 20 mcg per min
- Run wide open in your peripheral IV or IO until the patient’s hemodynamics stabilize.
- Can set up the pump, follow protocols, and perform double-checks.
- Adequate labeling is important to mitigate errors.
Or, compel your service administrators to buy the right equipment (IV Pumps) and the right vasopressor (Norepi).
Vasopressors Turn Unstressed Volume Into Stressed Volume
- Unstressed Volume – Volume of fluid to fill the vascular bed to the point where its presence exerts force on the vessel walls
- Stresssed Volume – Anything greater ⇒ which will exert an increasing degree of pressure on the venous vascular bed ⇒ determines flow
Vasopressor Classification – A Simpler Approach
- Pure vasopresors (isolated vessel squeeze)
- Vasopressor with ionotrophy (both vessel & heart squeeze)
- Ionotropes with vasodilators (heart squeeze & vasodilation)
Maximum doses vary greatly between institutions. It is likely that your hospital or agency has set a maximum dose for each vasopressor. Maximum doses can be exceeded if needed to maintain hemodynamics.
When to Titrate (frequency)
Tips for peripheral administration:
- Use well functioning 18-20G IV proximal to the wrist
- Place BP cuff on opposite arm
- Regularly inspect IV site for signs of extravasation
- Ask patient to report discomfort around IV site
- Be prepared to manage extravasation
- Prolonged administration = Central access
When properly mixing Push Dose Epinephrine, repeated entries into any one container should be limited to maintain integrity/sterility of the original container.
Ways to limit puncturing the carpuject, as described by Dr. Baum in the podcast:
Be cautious when stopping drips when delivering patient to the hospital. This is especially important with agents like vasopressors as they have short half-lives. Patients needing these for support may decline. Best practice is to transition to hospital product before discontinuing.
Reporting of infusion rates during hand off:
- Medication infusions need to be reported in a concentration per time
- Examples: mg/hr or mcg/kg/min or units/hr
- ml/hr is NEVER appropriate due to differing concentrations of medication infusions
- Vasopressors may be dosed in mcg/min or mcg/kg/min beware of units
- IV fluids like normal saline and lactate ringers ml/hr is appropriate.
Special thanks to Dr. Regan Baum for providing us with these notes and images. A few additions were made by Curbside to Bedside.
Now Listen to the Podcast:
1. Reynolds, P.M., et al., Management of extravasation injuries: a focused evaluation of noncytotoxic medications. Pharmacotherapy, 2014. 34(6): p. 617-32.
2. Medlej, K., et al., Complications from Administration of Vasopressors Through Peripheral Venous Catheters: An Observational Study. J Emerg Med, 2018. 54(1): p. 47-53.
3. Loubani, O.M. and R.S. Green, A systematic review of extravasation and local tissue injury from administration of vasopressors through peripheral intravenous catheters and central venous catheters. J Crit Care, 2015. 30(3): p. 653 e9-17.
4. De Backer, D., et al., Comparison of dopamine and norepinephrine in the treatment of shock. N Engl J Med, 2010. 362(9): p. 779-89.