Epinephrine

Aka: Epinephrine, Adrenaline

1. Definition
   1. Natural Catecholamine with Alpha and beta activity
2. History
   1. Medical case report in 1923 on intracardiac Adrenaline
      1. Shown to reverse "Acute heart paralysis"
3. Pathophysiology
   1. Alpha Adrenergic Agonist Effects
      1. Most important for Cardiac Arrest
      2. Vasoconstriction
         1. Increases Systemic Vascular Resistance
         2. Increases Systolic and Diastolic Blood Pressure
      3. Increases Vital Organ Perfusion
         1. Increases Myocardial perfusion
         2. Increases Cerebral perfusion
      4. Decreases Non-Vital Organ Perfusion
         1. Decreases splanchnic and intestinal perfusion
         2. Decreases renal perfusion
         3. Decreases skin perfusion
   2. Beta Adrenergic Agonist effects (Under 0.3 ug/kg/min)
      1. Increases myocardial contractility
      2. Increases Heart Rate
      3. Relaxes Bronchial smooth muscle (bronchodilation)
   3. Epinephrine has a short half-life: ~2 minutes
4. Indications
   1. Initial Resuscitation Management (bolus)
      1. Cardiac Arrest
         1. Vasopressin may be used instead in some protocols
      2. Symptomatic Bradycardia unresponsive to
         1. Oxygenation
         2. Ventilation
      3. Hypotension refractory to volume replacement
   2. Post-Resuscitation Stabilization (Infusion)
      1. Poor systemic perfusion or Hypotension despite
         1. Intravascular volume replacement AND
         2. Stable rhythm
      2. Significant Bradycardia
5. Dosing: Newborn (refractory and persistant Bradycardia)
   1. Epinephrine (1:10,000) 0.1 to 0.3 ml/kg by IV or ET
   2. Do not use the 1:1000 concentration in newborns
6. Dosing: Pediatric
   1. Symptomatic Bradycardia (with a pulse)
      1. Dose: 0.01 mg/kg IV/IO (0.1 ml/kg of 1:10,000 Epi)
   2. Pulseless Cardiac Arrest
      1. Initial regular dose Epinephrine
         1. Dose: 0.01 mg/kg IV/IO (0.1 ml/kg of 1:10,000 Epi)
      2. Subsequent High Dose Epinephrine (if no effect above)
         1. Dose: 0.1 mg/kg IV/IO (0.1 ml/kg of 1:1000 Epi)
         2. Maximum dose: 0.2 mg/kg
      3. Repeat dose every 3-5 minutes
   3. Endotracheal Administration
      1. Adults and children: 0.1 mg/kg (0.1 ml/kg of 1:1000)
      2. Newborn: 0.1 mg/kg (1 ml/kg of 1:10,000)
7. Dosing: Pediatric Infusion (Same as Isoproterenol preparation)
   1. Preparation
      1. Draw up "x" mg of Epinephrine
      2. Where "x" = 0.6 x WeightKg
      3. Add enough D5W or NS to Epinephrine for 100 ml total
      4. At this dilution
         1. Infusion rate of 1 ml/h provides 0.1 ug/kg/h
   2. Start Dose: 20 ml/hour until Tachycardia
      1. Indicates drug has entered circulation
   3. Titrate Dose
      1. Decrease to desired rate (0.1 - 1.0 ug/kg/min)
      2. Adjust infusion rate every 5 min to desired effect
8. Dosing: Adult Pulseless Arrest
   1. Rhythms
      1. Asystole
      2. Pulseless Electrical Activity
      3. Ventricular Fibrillation
   2. Initial
      1. IV: 1 mg (10 ml of 1:10,000 Epi) IV push
      2. Endotracheal: 2.5 ml of 1:1000 Epi in 10 ml NS
   3. Repeat every 3-5 minutes
   4. Consider increasing dose to 3 or 5 mg (0.1 mg/kg)
9. Dosing: Adult Infusion for Cardiac Arrest
   1. Preparation
      1. Draw up 30 mg of Epinephrine (30 ml of 1:1000)
      2. Add Epinephrine to 250 ml Normal Saline or D5W
   2. Start Dose: 100 ml/h
   3. Titrate to desired effect
10. Dosing: Adult Infusion for symptomatic Bradycardia
    1. Preparation
       1. Draw up 1 mg Epinephrine (1 ml of 1:1000)
       2. Add Epinephrine to 500 ml Normal Saline or D5W
    2. Start Dose: 1 ug/min
    3. Titrate Dose to desired effect (2-10 ug/min)
11. Dosing: Adult Push Dose Pressor for Hypotension refractory to fluid bolus
    1. See Intravenous Phenylephrine
    2. Preparation
       1. Start with 9 ml of Normal Saline in 10 ml syringe
       2. Draw 1 ml of Cardiac Epinephrine (100 mcg/ml) in vial
       3. Final Concentration: Epinephrine 10 mcg/ml
    3. Dose
       1. Epinephrine (10 mcg/ml) 0.5 to 2 ml (5-20 mcg) every 2-5 minutes
       2. Expect onset of action within 1 minute and effect lasting 5-10 minutes
12. Precautions
    1. Carefully check concentration (1:1000 OR 1:10,000)
    2. Observe for side effects after Resuscitation
       1. Supraventricular Tachycardia
       2. Ventricular Tachycardia
       3. Severe Hypertension
    3. Extravasation into tissues
       1. may causes local ischemia or necrosis
    4. Can exacerbate Myocardial Ischemia
    5. Do not mix with alkaline solutions