D represents the administration of drugs. If bradycardia is unresponsive to ventilation or if asystole is present, epinephrine should be administered. Intravenous (IV) epinephrine (1:10,000), 0.1 to 0.3 mL/kg, should be given through an umbilical venous line or injected into the endotracheal tube. However, when epinephrine is administered through the endotracheal tube, the result is often unpredictable. Before medications are administered in the presence of electrical cardiac activity with poor pulses, it is important to determine whether there is a pneumothorax. Transillumination of the thorax, involving the use of a bright light through each side of the thorax and over the sternum, may suggest pneumothorax if one side transmits more light than the other. Breath sounds may be decreased over a pneumothorax and there may be a shift of the heart tones away from the side of a tension pneumothorax.
If central nervous system depression in the infant may be due to a narcotic medication given to the mother, 0.1 mg/kg of naloxone (Narcan) can be given to the infant intravenously or endotracheally. Before this drug is administered, the ABCs should be followed carefully. Naloxone should not be given to a newborn of a mother who is suspected of being addicted to narcotics or is on methadone maintenance because the newborn may experience severe withdrawal seizures.
In babies of more than 35 weeks’ gestation suffering hypoxic ischemic injury at birth, induced therapeutic hypothermia(33.0°C to 34.0°C) for 72 hours has been shown in clinical studies to be efficacious in reducing the severity of brain injury. Brain hypothermia, whether induced by whole-body or selective head cooling, provides neuroprotection against encephalopathy presumably due to hypoxic ischemia.
The first physical examination of a newborn may be a general physical examination of a well infant or an examination to confirm fetal diagnoses or to determine the cause of various manifestations of neonatal diseases. Problems in the transition from fetal to neonatal life may be detectable immediately in the delivery room or during the first day of life. Physical examination also may reveal effects of the labor and delivery resulting from asphyxia, drugs, or birth trauma. The first newborn examination is an important way to detect congenital malformations or deformations (Table 58-9). Significant congenital malformations may be present in 1% to 3% of all births.
Signs such as cyanosis, nasal flaring, intercostal retractions, and grunting suggest pulmonary disease. Meconium staining of the umbilical cord, nails, and skin suggest fetal distress and the possibility of aspiration pneumonia. The level of spontaneous activity, passive muscle tone, quality of the cry, and apnea are useful screening signs to evaluate the state of the nervous system.
The examination should proceed with an assessment of vital signs, particularly heart rate (normal rate, 120 to 160 beats/min); respiratory rate (normal rate, 30 to 60 breaths/min); temperature (usually done per rectum and later as an axillary measurement); and blood pressure (often reserved for sick infants). Length, weight, and head circumference should be measured and plotted on growth curves to determine whether growth is normal, accelerated, or retarded for the specific gestational age.
Figure 58-3 Physical criteria for assessment of maturity and gestational age. Expanded New Ballard Score (NBS) includes extremely premature infants and has been refined to improve accuracy in more mature infants. (From Ballard JL, Khoury JC, Wedig K, et al: New Ballard Score, expanded to include extremely premature infants, J Pediatr 119:417-423, 1991.)