II. Background
- See specific medications (follow links) for preparation and dosing protocols
- Vasopressors decrease hypoperfusion via Vasoconstriction and increased cardiac contractility
- Vasopressors are typically used via Central Line access
- However may be used peripherally for stabilization in first 1-2 hours (see precautions below)
- Push Dose Pressors are typically used via Peripheral IV Access (see below)
III. Precautions: General
- Vasopressors are second-line therapy for Hypotension after cause-specific measures
- Start with at least 30 ml/kg of crystalloid in Septic Shock
- Replace acute blood loss with blood
- Frequently reevaluate volume status, perfusion markers (e.g. Lactic Acid) and Hypotension response
- Typical targets in adults
- See Pediatric Vital Signs
- See Hypotension
- Mean Arterial Pressure >65 mmHg
- Systolic Blood Pressure >90 mmHg
- Improved end organ perfusion (e.g. mental status)
- Vasopressors have associated risks
- Increased myocardial demand
- Arrhythmia
- Vasoconstriction with decreased perfusion of some end organs
IV. Precautions: Peripheral Vasopressor administration
- Do not use Vasopressors via unreliable, small or deep peripheral site
- Use only larger bore, reliable superficial IVs that can be closely monitored
- Avoid peripheral hand IV or Ultrasound-guided deep brachial (occult extravasation risk)
- Best to transition within first 2 hours to Central Line Vasopressor delivery
- However, norepinephine may be safely used for 24 hours via large bore, reliable peripheral IV
- Monitor peripheral IV closely for extravasation
- See management below of Peripheral Vasopressor Extravasation
- Peripheral Vasopressor delivery appears safe for short-term use (studies looked at 12-24 hours)
- Recent studies have demonstrated Norepinephrine peripheral safety
- Push Dose Pressors (see below) also appear safe
- Ricard (2013) Crit Care Med 4(9): 2108-15 +PMID:23782969 [PubMed]
- Cardenas-Garcia (2015) J Hosp Med 10(9): 581-5 +PMID:26014852 [PubMed]
- Nguyen (2020) Am J Emerg Med +PMID: 31959524 [PubMed]
- Consult plastic surgery
- References
- Orman and Weingart (2016) EM:Rap 16(5): 12-3
V. Management: Peripheral Vasopressor Extravasation (IV Extravasation of Catecholamines)
- Direct others to obtain reliable access (other peripheral IV, IO Line, Central Line)
- Leave infiltrating catheter in place until following measures are completed
- Use the infiltrating catheter to withdraw as much infused Vasopressor from the site
-
Phentolamine
Mesylate SQ Immediately (even if skin site has not yet whitened)
- Dilute Phentolamine vial (5 mg/ml) in 9 ml Normal Saline
- Inject diluted Phentolamine 0.1 to 0.2 mg/kg (up to 5-10 mg) SQ into extravasation site
- Second dose may be needed
VI. Preparations: Push Dose Pressors (Bolus Dose Pressors)
- Indications
- Temporizing measure in severe Hypotension (MAP <60 mmHg)
- Bolus pressors typically via peripheral IV (prior to central access)
-
General
- Used initially prior to central Intravenous Access
- Medications are used in diluted form
- Both Epinephrine and Phenylephrine have onset of action within 1 minute
- Phenylephrine duration of action 10-20 minutes
- Epinephrine duration of action 5-10 minutes
- Precaution: Dosing errors are common (double check concentration and dose)!
- Label all syringes with medication and concentration
- Holden (2018) Ann Emerg Med 71(1): 83-92 +PMID:28601272 [PubMed]
-
Epinephrine (diluted to 10 mcg/ml)
- Epineprhine 10 mcg/ml, give 0.5 to 2 ml (5-20 mcg) every 2-5 minutes as needed
- See Epinephrine for dilution approach (do not use undiluted cardiac Epinephrine)
-
Intravenous Phenylephrine
- Phenylephrine (diluted to 10 mcg/ml) 0.5 to 2 ml (50-200 mcg) every 2-5 minutes as needed
- See Phenylephrine for dilution approach (do not use undiluted Phenylephrine)
-
Norepinephrine
- Norepinephrine is typically premixed at 16 mcg/ml (no dilution needed)
- Dose: 0.5 to 1 ml (8 to 16 mcg)
- Onwochei (2017) Anesth Analg 125(1): 212-8 +PMID:28248702 [PubMed]
- References
- Swaminathan and Weingart in Herbert (2018) EM:Rap 18(11): 3-4
VII. Preparations: Pressor Infusions - Alpha adrenergic agents (primarily)
-
Norepinephrine
- Indications
- Preferred first-line Vasopressor in adults
- Receptor Activity
- Alpha-1 Agonist
- Lower beta adrenergic activity
- Dosing (adults)
- Weight Based (preferred)
- Start at 0.05 mcg/kg/min
- Titrate to range 0.1 to 0.5 mcg/kg/min (7 to 35 mcg/min in a 70 kg adult)
- Unlikely to benefit from titration above 0.3 mcg/kg/min
- Non-weight based (adults)
- Start at 5 mcg/min (some recommend starting at 0.5 to 1.0 ug/min)
- Typical dose range: 2 to 30 mcg/min
- Weight Based (preferred)
- Effects
- Strong Vasoconstrictor
- Minimal chronotropic activity
- Adverse effects
- Reflex Bradycardia
- Tachyarrhythmia
- May precipitate Myocardial Ischemia or infarction
- Indications
-
Epinephrine
- Receptor Activity
- Alpha-1 Agonist
- Lower beta adrenergic activity
- Dosing (adults)
- Vasopressor: 2-10 mcg/min IV infusion
- Symptomatic Bradycardia: 2-10 mcg/min IV infusion
- Inotropic dosing: 0.01 to 0.08 mcg/kg/min IV infusion
- Push dose (see above): 5-20 mcg IV bolus every 2-5 min
- ACLS (pulseless Arrhythmia): 1 mg IV bolus every 3-5 min
- Effects
- Strong inotropy
- Strong chronotropy
- Adverse effects
- May precipitate Myocardial Ischemia or infarction
- Receptor Activity
-
Dopamine
- Indications
- Has been the preferred first-line Vasopressor in children (but significant risks)
- Largely replaced by Norepinephrine in adults in U.S.
- Theoretically safer than Norepinephrine when used peripherally
- However Norepinephrine is often initially used via a reliable peripheral IV safely
- Theoretically with greater renal protection than other Vasopressors
- Does not appear to offer any significant benefit over other Vasopressors in renal protection
- Receptor Activity
- Dosing
- Infusion: 5 to 20 mcg/kg/min IV infusion
- Effects
- Precursor to Norepinephrine
- Inotropy and chronotropy at moderate doses
- Strong Vasoconstrictor at higher doses
- Adverse Effects
- Increased risk for Dysrhythmia
- Three fold increased mortality in septic children
- Indications
-
Phenylephrine
- Indications
- Primarily used as a push-dose pressor (see above), especially by Anesthesia
- Receptor Activity
- Exclusively alpha-1 Agonist
- Dosing
- Infusion: 25-200 mcg/min
- Push Dose Pressor: 50-200 mcg every 2-5 min prn
- Effects
- Strong peripheral Vasoconstrictor (with increased Afterload)
- Minimal chronotropic activity
- Adverse effects
- Reflex Bradycardia
- Cardiogenic Shock (avoid use in reduced ejection fraction)
- Indications
VIII. Preparations: Pressor Infusions - Beta adrenergic agents (primarily)
- Precautions
- Inotropic and chronotropic agents with risk for worsening Hypotension
- Exercise caution in Hypotension
- Most providers use in combination with a low dose pure Vasopressor (e.g. Norepinephrine)
- Dobutamine
-
Milrinone
- Mechanism
- PDE inhibitor blocks breakdown of cyclic Adenosine monophosphate, sustains Catecholamine activity
- Receptor Activity
- Dosing
- Infusion: 0.125 to 0.5 mcg/kg/min
- Adverse Effects
- Hypotension risk (avoid in Hypovolemia)
- Effects
- Strong inotropy, increases Stroke Volume
- Decreases Afterload by dilating arterioles
- Mechanism
- Isoproteronol
- Indications
- Hypotension due to Bradycardia
- Receptor Activity
- Dosing
- Infusion: 2 to 10 mcg/min
- Effects
- Strong inotropy
- Strong chronotropy
- No significant vascular effect (although may decrease Systemic Vascular Resistance)
- Cardiac Output not appreciably affected
- Indications
IX. Preparations: Pressor Infusions - Other sites of activity
-
Vasopressin
- Indications
- Adjunct to other Vasopressors (e.g. Norepinephrine) in refractory Hypotension (especially Septic Shock)
- Receptor Activity
- Exclusively at Vasopressin receptors (some on vasculature)
- Dosing
- Infusion: 0.01 to 0.04 units/min
- Adverse effects
- Higher doses may be associated with ischemia
- Effects
- Increases Systemic Vascular Resistance while still maintaining CNS and cardiac Blood Flow
- Effective, even in severe acidosis
- Indications
X. Resources
- EM-Crit Blog (Scott Weingart)
XI. References
- (2022) ACLS Guidelines, AHA, accessed online 8/5/2022
- Goldberg (2015) Crit Dec Emerg Med 29(3): 9-19
- McCollum in Herbert (2019) EM:Rap 19(7):4-6