Medications and Vascular Access
Epinephrine
Epinephrine is indicated when the heart rate stays below 60/min despite 60 seconds of coordinated compressions with effective ventilation, ideally with 100% oxygen. The preferred route is IV/IO: 0.01–0.03 mg/kg of the 0.1 mg/mL concentration, given as a rapid push followed by a flush; the endotracheal route requires a higher dose, is less reliable, and should be used only while access is being obtained. Repeat every 3–5 minutes if the heart rate remains low. Give it without interrupting compressions.
Volume and access
Volume expansion (10 mL/kg of normal saline or blood over 5–10 minutes) is reserved for suspected blood loss - pallor with a poor response, a history of abruption, cord prolapse, or a twin-to-twin transfusion setting - not for routine bradycardia. Emergency umbilical venous access: insert a catheter just until blood returns, typically 2–4 cm, and do not advance further. Intraosseous access is an acceptable alternative. Naloxone, sodium bicarbonate, and atropine have no routine role in the delivery room.
Traps
Giving epinephrine while ventilation is still poor; discarding an endotracheal dose that has not yet circulated before giving IV epinephrine; using 1 mg/mL concentration errors; giving volume to every bradycardic infant.
Rule of thumb
Fix the breathing, then the pump, then the pharmacology. Worked example: HR 40 after 60 seconds of compressions on a 3 kg infant - epinephrine 0.03 mg (0.01 mg/kg × 3 kg of 0.1 mg/mL) IV push, flush, and reassess in 60 seconds.