FIGURE 32-1 Physiological changes associated with primary and secondary apnea in the newborn. bpm = beats per minute; HR = heart rate; MAP mean arterial pressure. (Adapted with permission from Kattwinkel J: Textbook of Neonatal Resuscitation, 6th ed. Elk Grove Village, American Academy of Pediatrics and American Heart Association, 2010.) events leading to apnea (Fig.
With oxygen deprivation and carbon dioxide (C02) elevation, there is a transient period of rapid breathing, and if it persists, breathing stops, which is termed primay apnea. This stage is accompanied by a fall in heart rate and loss of neuromuscular tone. Simple stimulation will usually reverse primary apnea. If oxygen deprivation and asphyxia persist, however, the newborn will develop deep gasping respirations, followed by seconday apnea. This latter stage is associated with a further decline in heart rate, fall in blood pressure, and loss of neuromuscular tone. Neonates in secondary apnea will not respond to stimulation and will not spontaneously resume respiratory eforts. Unless ventilation is assisted, death follows.
Clinically, primary and secondary apneas are indistinguishable, and thus, secondary apnea must be assumed. And, when a response to stimulation is not immediate, resuscitation with efective ventilation of the apneic newborn must be started quickly.
Immediately after birth and usually during the delay for umbilical cord clamping, newborn tone, respiratory efort, and heart rate are evaluated (Fig. 32-2). :Most term neonates are vigorous by 10 to 30 seconds after birth (Ersdal, 2012). For these, initial steps of warming the newborn can be done on the mother's chest or abdomen. Direct skin-to-skin contact with the mother and drying and covering the newborn with a warm blanket will help maintain euthermia (36.5 to 37.5°C). A vigorously crying newborn does not require routine oral suctioning (Carrasco, 1997; Gungor, 2006). Instead, bulb suctioning to remove secretions is best reserved for those who cannot clear secretions on their own due to apnea or copious secretions. Additional routine care steps include drying, gentle stimulation by rubbing the newborn's back, and continued observation during the transition period.
If not vigorous or if preterm, the neonate is carried to a prewarmed radiant warmer for the initial newborn care steps.
The initial wet birth blanket is removed to allow newborn drying. Cold stress is associated with multiple neonatal morbidities and mortality. Preterm infants are particularly vulnerable, and special steps to maintain euthermia include providing a warmer delivery room (>25°C), covering the neonatal head with either a plastic or wool hat, application of polyethylene plastic "ponchos" or wraps to slow evaporative heat losses, use of chemically activated thermal mattresses to reduce conductive heat loss, and administration of warm, humidified respiratory gases during respiratory stabilization (Perlman, 2015).
At the radiant warmer, newborns must be positioned to maximally open the airway, with mild extension of the neck. If the newborn is apneic or has copious secretions that it cannot clear, a bulb syringe or suction catheter may be used to clear the mouth and then the nose. Routine intubation and suctioning of meconium-stained amnionic luid is no longer recommended for the nonvigorous newborn (American College of Obstetricians and Gynecologists, 2017b; Perlman, 2015). Intubation and suction are reserved for suspected airway obstruction.
After completion of the initial stabilization steps, apnea, gasping respirations, or heart rate � 100 beats per minute (bpm) should prompt immediate administration of positivepressure ventilation with room air (Fig. 32-3). his should be started by 60 seconds of life, if not sooner, once the initial steps are completed.