Overview
Definition:
Epinephrine (adrenaline) is a cornerstone medication in neonatal resuscitation, indicated for profound bradycardia or asystole unresponsive to initial resuscitative measures like ventilation and chest compressions
It is a potent sympathomimetic amine that increases heart rate, contractility, and systemic vascular resistance.
Epidemiology:
Neonatal resuscitation is required in approximately 10% of all births, with a smaller percentage requiring advanced interventions including medications
Bradycardia is a common indication for epinephrine administration in this population, often associated with hypoxemia and acidosis.
Clinical Significance:
Accurate and timely administration of epinephrine is critical for improving outcomes in neonates experiencing cardiorespiratory arrest or severe bradycardia
Inappropriate dosing or route selection can lead to ineffective resuscitation or adverse effects, impacting survival and neurological outcomes.
Indications And Timing
Indications:
Profound bradycardia (heart rate < 60 beats per minute) despite effective positive pressure ventilation and chest compressions
Asystole or pulseless electrical activity during neonatal resuscitation.
Timing:
Epinephrine administration should be considered if bradycardia persists (HR < 60 bpm) after 30 seconds of effective chest compressions and ventilation
It is also the first-line pharmacologic agent for asystole
Continuous infusions may be initiated for persistent bradycardia or hypotension post-resuscitation.
Dosing And Concentration
Initial Bolus Dose:
The recommended initial dose of epinephrine is 0.01 to 0.03 mg/kg
This is typically prepared using a concentration of 1:10,000 (0.1 mg/mL).
Preparation For Bolus:
For a 1:10,000 concentration, a common volume calculation for a 3 kg neonate at 0.02 mg/kg would be (0.02 mg/kg * 3 kg) / (0.1 mg/mL) = 0.6 mL
Alternatively, the 1:100,000 (0.01 mg/mL) concentration can be used at 0.1 to 0.3 mL/kg.
Epinephrine Concentration Clarification:
It is crucial to use the 1:10,000 (0.1 mg/mL) or 1:100,000 (0.01 mg/mL) concentration for intravenous or intraosseous administration
The 1:1,000 (1 mg/mL) concentration is NEVER used for IV/IO administration in neonates due to the risk of overdose.
Routes Of Administration
Umbilical Venous Catheter Iv:
The umbilical venous catheter (UVC) is the preferred route for rapid administration of medications, including epinephrine, during neonatal resuscitation
Infusion should be followed by a saline flush of 1 mL/kg to ensure drug delivery to the central circulation.
Intraosseous Io:
Intraosseous (IO) access is a valuable alternative route when venous access cannot be rapidly established
It provides rapid access to the systemic circulation
Dosing and preparation are the same as for IV administration.
Endotracheal Tube Et:
Endotracheal (ET) administration is a less reliable route and is typically reserved as a last resort if IV/IO access cannot be achieved
The dose for ET administration is higher, generally 0.1 mg/kg (1 mL/kg of 1:10,000 solution)
Absorption is variable and may be enhanced by chest compressions and deep inspirations.
Intracardiac:
Intracardiac epinephrine is rarely indicated and is generally considered only if other routes have failed and the chest is open for direct cardiac massage
This route carries significant risks and is typically performed by experienced clinicians.
Infusion Protocol Post Resuscitation
Indications For Infusion:
Continuous epinephrine infusion may be indicated for persistent bradycardia or hypotension following initial resuscitation, or for specific conditions like persistent pulmonary hypertension of the newborn.
Infusion Rate:
The recommended starting dose for a continuous infusion is typically 0.05 to 0.1 mcg/kg/min, titrated to achieve desired hemodynamic effects (e.g., heart rate, blood pressure)
Higher doses may be used in specific refractory cases.
Preparation For Infusion:
The infusion is usually prepared by adding epinephrine (1 mg vial of 1:1000 concentration, or equivalent of 1:10,000) to a specific volume of dextrose solution (e.g., 100 mL or 250 mL of D10W) to achieve a concentration (e.g., 10 mcg/mL or 20 mcg/mL) allowing for accurate titration
Always confirm the final concentration and infusion rate calculation.
Monitoring And Adverse Effects
Monitoring Parameters:
Continuous cardiac monitoring for heart rate and rhythm is essential
Blood pressure monitoring (invasive if possible) is crucial
Assess peripheral perfusion, respiratory status, and acid-base balance.
Adverse Effects:
Potential adverse effects include tachycardia, hypertension, arrhythmias, myocardial ischemia, central nervous system excitation, and peripheral vasoconstriction leading to organ hypoperfusion
Accurate dosing and monitoring help mitigate these risks.
Key Points
Exam Focus:
Remember the 1:10,000 concentration for IV/IO boluses (0.01-0.03 mg/kg)
Differentiate this from the higher dose and concentration for ET administration (0.1 mg/kg of 1:10,000)
Know the indications for continuous infusions and common starting rates.
Clinical Pearls:
Always confirm the concentration of the epinephrine vial before drawing up medication
Double-check calculations, especially when switching between bolus and infusion preparations
UVC is the preferred route for rapid delivery
IO is an excellent alternative
ET is a last resort.
Common Mistakes:
Using the 1:1,000 concentration for IV/IO administration is a critical and potentially fatal error
Incorrect calculation of doses for weight or volume
Delaying administration of epinephrine when indicated after initial resuscitation efforts.