10.1 Epinephrine

Why Medications Are Rare—and Why Timing Still Matters

Most newborns who need help respond to warmth, airway opening, and effective positive-pressure ventilation. Only a small fraction ever require chest compressions, and an even smaller group needs epinephrine. That rarity is good clinical news—and a common exam trap. Providers who jump to drugs for every low heart rate miss the foundation of neonatal resuscitation: air entry first. Providers who wait too long once compressions are truly ongoing delay the one drug that can restore coronary perfusion pressure when the hypoxic myocardium will not recover with ventilation and compressions alone.

Epinephrine is not a “boost” for mild bradycardia. It is a last-line vasoactive used when the heart rate stays critically low despite optimized ventilation (preferably through an advanced airway), 100% oxygen, and coordinated chest compressions. If you remember only one indication sentence for the Provider exam, make it this:

Give epinephrine when the heart rate remains below 60 bpm after effective ventilation and at least about 60 seconds of coordinated compressions.

Exact Indication (Unpack Every Word)

Contrast earlier algorithm boxes so you never collapse them:

• Apnea / gasping / HR <100 → PPV
• HR <60 after ≥30 s effective PPV → compressions + 100% O₂
• HR still <60 after effective ventilation + coordinated compressions → epinephrine + ensure vascular access

Giving epinephrine for HR 90, or before the lungs are ventilated, is as wrong as refusing epinephrine when HR has been 30–40 through a full minute of good CPR.

Concentration: 0.1 mg/mL (1:10,000)

NRP uses epinephrine 0.1 mg/mL, still often labeled by the older ratio 1:10,000. This is not the 1 mg/mL (1:1,000) concentration used for anaphylaxis IM dosing in older patients. Using the wrong concentration can deliver a tenfold overdose or underdose.

Exam and cart discipline:

• Read the vial label out loud: “Epinephrine zero-point-one milligrams per milliliter.”
• Draw from the correct neonatal resuscitation concentration.
• Do not improvise adult code-cart math under stress without a second person verifying dose and concentration.

Preferred Route and Dose: IV / IO

Preferred route

Intravenous (or intraosseous) epinephrine is preferred—most often through an emergency low umbilical venous catheter (UVC) in the delivery room. IV/IO delivery places drug into the central circulation with the most reliable onset. Intramuscular, subcutaneous, and oral routes are not NRP pathways for bradycardic arrest in the newly born.

Dose range (memorize both mg/kg and mL/kg)

Many NRP courses emphasize 0.02 mg/kg (0.2 mL/kg) as a practical initial IV/IO target inside the official range. Subsequent doses may be considered toward the upper end of the range (up to 0.03 mg/kg) if heart rate remains <60 and ventilation/compressions remain optimized—follow current NRP textbook teaching and local protocol for titration language on your exam form.

Worked example (exam-style math):

• Estimated weight 3 kg
• Start dose 0.02 mg/kg → 0.06 mg
• Volume of 0.1 mg/mL: 0.2 mL/kg × 3 kg = 0.6 mL IV/IO
• Then flush (below)

Always know approximate weight (or use a weight-based reference chart / length-based tape as your unit trains) before the first dose is drawn.

Endotracheal Epinephrine: Bridge Only, Higher Dose

If vascular access is not yet available, epinephrine may be given down the endotracheal tube while the team places a UVC or IO line. Pulmonary absorption is unreliable, so the ET dose is higher than the IV dose:

• ET dose ≈ 0.05–0.1 mg/kg (higher than IV/IO 0.01–0.03 mg/kg)
• Often taught near 0.1 mg/kg (about 1 mL/kg of 0.1 mg/mL) as a practical ET target within that higher band—confirm against your course materials

Critical rules:

1. ET epinephrine is a temporary bridge, not the preferred definitive route.
2. As soon as UVC or IO access is ready, give IV/IO epinephrine if HR is still <60—even if an ET dose was already given.
3. Do not assume the baby “got a full dose” via the tube and stop trying for access.
4. Do not delay establishing access forever while repeating ET doses as the only strategy.

Flush After IV / IO Epinephrine

After injecting epinephrine through a UVC or IO needle, flush the catheter with normal saline so the drug does not sit in tubing dead space. NRP teaching commonly specifies about 3 mL of normal saline after IV/IO epinephrine (often taught as 3 mL for all birth weights in recent editions). Follow the flush volume taught in your current NRP materials and local protocol; the non-negotiable principle is that a flush is required after the drug dose so epinephrine reaches the central circulation.

Without a flush, a correct milligram calculation can still fail clinically because the dose never left the catheter lumen.

Repeat Interval: Every 3–5 Minutes

If heart rate remains below 60 despite effective ventilation and compressions, repeat epinephrine every 3 to 5 minutes. Between doses:

• Confirm chest movement and advanced-airway position
• Maintain 3:1 CPR quality and 100% oxygen
• Continue efforts at reliable vascular access if not already secured
• Reassess heart rate on a planned cadence (about every 60 seconds of CPR), not with constant long interruptions

Epinephrine is not “once and done.” It is also not “every 30 seconds.” The 3–5 minute interval is the standard NRP repeat window.

Prepare Early When Compressions Start

The moment the team correctly starts compressions, cognitive load spikes. Waiting until the first 60-second reassess to even open the drug box wastes recoverable time. Best practice and exam-aligned teamwork:

1. When compressions are indicated, assign someone to prepare epinephrine (correct concentration, weight-based volume) and emergency UVC/IO equipment.
2. Leader announces the plan: “Heart rate still under 60 after effective ventilation—compressions, 100% oxygen; prepare epi and umbilical access.”
3. Draw and label the dose with closed-loop read-back: concentration, mg/kg, mL to give, route, flush plan.
4. Do not interrupt compressions for long periods to search for supplies—equipment for meds and access should already be on the warmer checklist for high-risk births.

What Epinephrine Does (So You Use It for the Right Problem)

Epinephrine is an adrenergic agonist. In asphyxial bradycardia it helps by:

• Increasing systemic vascular resistance (alpha effect), which raises aortic diastolic pressure and improves coronary perfusion pressure during compressions
• Supporting heart rate and contractility (beta effects) once coronary flow improves

It does not:

• Replace missing intravascular volume in hemorrhagic shock (that is volume expansion—next section)
• Fix ineffective ventilation
• Treat primary hypoglycemia, pneumothorax, or airway malposition

If the baby remains bradycardic after multiple correctly dosed, flushed IV epinephrine doses, the team must re-check the fundamentals (tube position, bilateral breath sounds, pneumothorax, severe hypovolemia, equipment failure) rather than only escalating drug milligrams blindly.

High-Yield Trap Table

Scenario Drill

Scenario A — Correct use. Term infant, intubated, chest rising, 100% O₂, 3:1 CPR for ~60 seconds, ECG HR 40. Team gives 0.02 mg/kg IV via UVC, flushes with saline, continues CPR, plans reassess and possible repeat in 3–5 minutes.

Scenario B — Too early. HR 55 during face-mask PPV with no chest rise. Correct priority: MR SOPA / airway, not epinephrine.

Scenario C — Wrong concentration. Someone hands up “epi 1:1,000.” Correct action: reject and obtain 0.1 mg/mL (1:10,000); do not inject the wrong strength.

Scenario D — ET bridge. No UVC yet; ETT in place; HR still 35 after CPR. Give higher-dose ET epinephrine while another provider places emergency UVC/IO, then give IV/IO dose if still indicated.

Quick Reference Card

Master epinephrine as a package: indication, concentration, preferred route, dose range, flush, repeat interval, and early preparation. Exam stems almost always test one missing piece of that package.