General examination initial and subsequent assessments

`Examination of the Newborn Infant
Examination of the Newborn Infant
GENERAL EXAMINATION
INITIAL AND SUBSEQUENT ASSESSMENTS
Immediately after birth, all infants should be briefly examined for major congenital abnormalities, signs of serious illness, or discrepancy between expected gestational age and weight for gestation. The number of nursing evaluations in the next few hours depends on anticipated problems and should focus on heart rate, respiratory rate and effort, temperature, skin perfusion, skin color, and neuromuscular activity. Observation of the first feeding, usually within 4 hours of birth, indicates any underlying difficulty with sucking and swallowing. If no abnormalities are noted at birth, further newborn observation should occur at least every 8 hours. Any abnormalities detected at any time warrant more frequent, thorough examinations and possible investigation and initial therapy.
All infants should undergo a detailed medical examination within 24 hours of birth to ensure that investigation, treatment, or preventive management, when indicated, is implemented as soon as possible and to answer any concerns that a parent may have. Reassurance to a mother (or guardian) shortly after delivery is immensely important regardless of maternal experience with deliveries.¹ Further detailed examinations are necessary if any neonatal problems are detected; infants discharged early, before 24 hours, should be reexamined by 3 to 4 days of age.
PRINCIPLES
The neonatal examination is best performed in an appropriately equipped, warm, draft-free room, preferably with the mother present; examining the infant under a servocontrolled radiant warmer is an alternative. Thorough hand-washing before and after handling each infant is essential to prevent the spread of pathogenic organisms. If possible, the infant’s mother or guardian should be present during the examination so the examiner may address any specific parental concerns or questions and observe parental-infant interaction. Observation of the infant’s appearance, posture, and state of consciousness should precede the formal aspects of palpation and auscultation. Presence of 1 anomaly suggests presence of another, since anomalies often coexist. Constellations of physical findings may indicate the presence of a syndrome. Evidence of trauma in one part of the baby should lead to a search for trauma in other areas. Signs of birth trauma are particularly common in large infants and in infants who underwent difficult deliveries such as breech or forceps delivery.
The obstetric history of the pregnancy and delivery may provide a clue or sign of possible neonatal problems. For example, polyhydramnios may signal bowel obstruction; oligohydramnios may signal renal anomalies and pulmonary insufficiency; small-for-gestational-age and postmature infants are suspect for hypoglycemia and polycythemia; and prolonged rupture of the membranes, maternal fever, and fetal tachycardia may signal neonatal sepsis. The neonatal consequences of intrauterine growth restriction, prematurity, multiple births, maternal diabetes, and meconium-stained amniotic fluid are discussed in detail in other sections.
GESTATIONAL AGE AND SIZE
The infant’s gestational age should be estimated and body size compared with appropriate normal standards.
There are several ways to estimate gestational age, including reliable maternal history (based on known first day of the last menstrual period and regular pattern of menstruation before conception), prenatal ultrasound scan taken before 20 weeks of gestation, and physical characteristics of the skin, external genitalia, ears, breasts, and neuromuscular behavior of the newborn infant (Fig. 44-1).^2-4Preterm (or premature) infants have less than 37 completed weeks of gestation, term infants have completed 37 to 42 weeks, and postterm (or postmature) infants are past 42 weeks of gestation.
Birth weight, occipitofrontal head circumference, and crown-to-heel length should be measured and recorded. Length is measured from vertex to heel with the infant’s legs fully extended. These measurements are then compared for gestational age against standard growth charts (Fig. 44-2).⁵ Ideally, growth charts for the specific population should be used. Babies born to mothers living at high altitude are smaller than babies born at or near sea level. An infant is considered to be appropriate for gestational age if it falls within 2 standard deviations of the mean on these charts.⁶ Infants who are more than 2 standard deviations below the mean are small for gestational age, and those more than 2 standard deviations above the mean are large for gestational age. Both groups need special observation⁷ (see Chapters 47 and 48). Twenty percent of infants with serious congenital malformations are small for gestational age.⁸
GENERAL INSPECTION
Most babies born at term cry at birth, quickly establish normal regular breathing, and may remain awake and quite active for 30 minutes or more, during which the eyes are open; they make sucking, chewing, and swallowing movements; and they may have bursts of flexion and extension of the arms and legs with facial grimaces. This activity may be continuous or interspersed with quiet periods. Following the first few hours after birth, the normal term baby spends approximately 80% of the time in active or quiet sleep. The remaining 20% of the time is spent awake in varying states of activity with or without crying.
When the infant cries, the cry should be vigorous. A weak or whimpering cry is abnormal and warrants closer examination of the baby. A high-pitched or shrieking cry suggests an underlying neurologic problem. A hoarse cry may result from vocal cord paralysis, hypothyroidism, or trauma to the hypopharynx.
Initially, infants often adopt a position similar to that assumed in utero (eFig. 44.1  ). Placing a crying infant into this posture often calms the infant. About 2% of infants have significant deformities caused by mechanical forces that acted in utero to restrict motion or to create pressure on the limbs, spine, thorax, or skull. Mechanical forces include oligohydramnios, uterine malformations, or multiple pregnancies.
TEMPERATURE
The normal infant is pink, well-perfused, and feels warm to the touch, but exposure to even a moderately cold environment leads to the hands and feet quickly becoming cool and slightly cyanotic. The normal axillary temperature is between 36.5 °C and 37.4 °C. The most common reasons for a low or high temperature are exposure to a cool environment and overheating (see Chapter 43). However, persistence of an abnormal temperature in a normal thermal environment indicates underlying pathology. Hypothermia may also occur with hypoglycemia, hypoxia, or hypothyroidism. Hyperthermia can be seen during drug withdrawal and with intracranial or adrenal hemorrhage.