1 What physiologic changes take place during the transition from intrauterine to extrauterine life?

The cardiopulmonary systems undergo a rapid change from fetal to extrauterine life. At birth the umbilical cord is clamped, and systemic vascular resistance rises. With the newborn’s first breaths (increasing the neonate’s PaO₂ and pH), pulmonary vascular resistance decreases, thereby causing an increase in pulmonary blood flow. Blood flow through the foramen ovale and the ductus arteriosus reverses direction, and then these structures eventually close. The ductus arteriosus is usually closed functionally by 15 hours of age.

If the pulmonary vascular resistance does not fall adequately, a persistent right-to-left shunt will occur (persistent pulmonary hypertension). Inability to expand alveolar spaces can cause intrapulmonary shunting of blood (hypoxia). Disruption of fetal maternal circulation (placenta previa, abruption placentae) can result in acute blood loss and hypovolemia in the newly born infant.

2 What preparation is necessary for the unexpected emergency department (ED) delivery?

Preparation is key, as most ED deliveries are “unexpected.” A prearranged plan should be set in motion as soon as birth is imminent. That plan should include the assembly of personnel who are best able to take care of the newly born infant. A brief history should be obtained if possible because it may affect the resuscitation. Equipment and medications specifically for a neonatal resuscitation should be kept in a designated tray so they are quickly available (Table 2-1). Periodic inspection of this equipment for proper functioning and expiration dates of medication should become part of the routine upkeep of the neonatal resuscitation tray.

Table 2-1 Equipment and Drugs for the Neonatal Resuscitation

Equipment

Gowns, gloves, and masks

Warm towels and blankets

Bulb syringe

Meconium aspirator

Suction catheters (sizes 5–10 Fr)

Face masks (sizes premature, newborn, and infant)

Oral airways (sizes 000, 00, 0)

Anesthesia bag with manometer (preferably 500 mL, no larger than 750 mL)

Laryngoscope with straight blades (sizes 0 and 1)

Spare bulbs and batteries

Stethoscope

Endotracheal tubes (sizes 2.5, 3.0, 3.5, 4.0) and stylet

Tape

Umbilical catheters (3.5 and 5 Fr)

Oxygen source with flow meter

Umbilical catheter tray

Three-way stopcocks

Nasogastric feeding tubes (8 and 10 Fr)

Needles and syringes

Chest tubes (8 and 10 Fr)

Magill forceps

Radiant warmer

Cardiorespiratory monitor with electrocardiography leads

Pulse oximeter with neonatal probes

Suction equipment and tubing

Pulse oximeter with newborn probe

End-tidal CO2 detector

Laryngeal mask airway (optional)

Drugs

Epinephrine 1:10,000

Naloxone

Sodium bicarbonate

Dextrose in water 10%

Normal saline, lactated Ringer’s

Resuscitation drug chart

3 What problems should be anticipated for a preterm delivery (< 37 weeks’ gestation)?

Preterm babies have immature lungs that may be more difficult to ventilate and more prone to injury by positive-pressure ventilation. Premature infants are also more prone to intracranial hemorrhage because they have immature blood vessels in the brain. In addition, these infants are at risk for rapid heat loss because of their thin skin and large surface area. Finally, premature infants are at increased risk for infection and hypovolemic shock caused by small blood volume.

American Heart Association: Part 13: Neonatal Resuscitation Guidelines. Circulation 112:IV-188–195, 2005.

4 What are the critical facts in the history that should be elicited, if possible, prior to delivery?

The standard maternal history is important but may need to wait until after delivery because of the imminent birth of the infant. Critical information may need to be narrowed to facts that may affect the immediate preparation (equipment and personnel) for the delivery:

Hazinski MF (ed): Textbook of Pediatric Advanced Life Support. Dallas, American Heart Association, 2002.

5 What steps should be taken initially to care for the newly born infant?

Since newly born infants do not tolerate cold, and hypothermia can prolong acidosis, prevent heat loss as much as possible. Dry the infant of the amniotic fluid and place the newborn in slight Trendelenburg position, on his or her back with the neck slightly extended, under a prewarmed radiant warmer. Suction the mouth and then nose with the bulb syringe or catheter. Duration of the suctioning should not exceed 5 seconds, and the tip should not be passed farther than 5 cm. Vigorous suctioning will cause bradycardia. Usually by drying and suctioning the infant, he or she is adequately stimulated to begin effective respirations. Gently flicking the heels and rubbing the back are additional stimulation methods. Avoid vigorous stimulation. Wrapping the newly born infant in warmed blankets will reduce heat loss.

6 How can a very–low-birthweight premature newborn infant (< 1500 gm) be kept warm in the ED?

Drying and swaddling, warming pads, increased environmental temperature, covering with a blanket, and placing the baby skin-to-skin with the mother have all been used to keep newborns warm. These techniques have not been evaluated in controlled trials and may not be enough to warm very small newborns. Very–low-birthweight infants may need additional warming techniques, such as covering the infant in plastic wrapping (food-grade, heat-resistant plastic) and placing him or her under radiant heat.

Costeloe K, Hennessy E, Gibson AT, et al: The EPICure study: Outcomes to discharge from hospital for infants born at the threshold of viability. Pediatrics 106:659–671, 2000.