Evaluating the Newborn: Diagnostic Approach

chapter 4 Evaluating the Newborn


Diagnostic Approach





Ideally, if you are going to care for a newborn, you should get to know the family before the child’s birth. This step is often taken by physicians in private practice but should be encouraged more widely. It makes antenatal care more comprehensive and helps the family care for the baby with as little anxiety as possible. Meeting the parents well before the delivery helps you become familiar with the prenatal history and makes you aware of important family issues. Your main sources of information should be the following:








Case History


The first-time mother of a 1-day-old baby boy who is being readied for discharge from the hospital has asked you to assess her baby. She is concerned that his color is poor and that he is not yet feeding well. When you ask about her specific concerns, she states that his hands and feet look blue when he is out to feed, that breastfeeding is not going well, and that he seems sleepy. The nurses have spent a lot of time with the mother trying to ease her concerns, but she is convinced that something is terribly wrong and that going home will put him in danger.


The infant, named Jonathan, was delivered vaginally at 38 weeks gestation following an uncomplicated pregnancy. When you arrive, both parents and the father’s sister are present and the mother is visibly upset and crying. The father voices the concern that Jonathan may have a heart condition underlying the color change and poor feeding, and he is refusing to allow his wife and baby to be discharged.


The experienced clinician will try to establish the root causes for the family’s concerns. For example, there may be another child with congenital heart disease with whom Jonathan is being compared. It also is important to allow the parents to voice their concerns about going home and to try to gain a better understanding about why the mother is so upset. A careful reexamination of the baby, preferably in the presence of the parents, is necessary.


There is a range of normal variation in peripheral cyanosis in the first few days after birth, particularly in situations in which the baby is exposed to cooler temperatures and when the limbs are in dependent positioning. Difficulties in establishing breastfeeding also are not uncommon, and most infants, after initial periods of wakefulness and good attempts at feeding, will experience a period of increased sleeping and less vigorous feeding. When infants and mothers are first learning to breastfeed, it is important that attention be paid to thermoregulation and positioning. Peripheral cyanosis, which is most often benign, is not uncommonly interpreted by brand-new parents as a worrisome sign and results in excessive anxiety and concern.


This chapter describes the usual activity of a newborn infant with tips on how to distinguish normal neurologic signs of tone and activity. A clear description of the cardiovascular examination is given, including some useful information about when to become concerned about murmurs or change in pulses.



Obtaining the History


Table 4–1 lists the important issues to ask about when obtaining any antenatal history.


TABLE 4–1 Significant issues to ask about when taking the History for a Newborn























































































Mother’s past pregnancies and their outcome No. of pregnancies
Stillbirths
Abortions
Neonatal deaths
Cesarean sections
Specific concerns that parents may have about current pregnancy because of past experiences
Preexisting systemic illness in mother and maternal medications Hypertension
Depression
Diabetes
Seizure disorder
Thyroid disease
Cardiac disease
Metabolic disorder (phenylketonuria)
Genetic history History of inherited disorders
Consanguinity
Unexplained neonatal deaths in the family
History of current pregnancy Date of last menstrual period
Use of assisted reproductive technologies or fertility treatments
Estimated date of conception by dates (and by ultrasonography if early ultrasonogram [9–13 weeks] available)
Results of ultrasonography, amniocentesis, cordocentesis, chorionic villus sampling
Pregnancy-induced hypertension, gestational diabetes
Note maternal weight gain and blood pressure, fetal growth, blood type
History of alcohol use, drug use (prescribed or illicit), cigarette use
Group B Streptococcus status (if known)
History of maternal surgery during pregnancy
Concerns about placenta (e.g., placenta previa or thickening)
Use of magnesium sulfate, betamethasone
Current labor and delivery Induced or spontaneous labor (if induced, why?)
Time of rupture of membranes and quality of amniotic fluid (bloody, meconium-stained)
Length of second stage
Use of medications (analgesics and time prior to delivery)
Intrapartum fever and antibiotics
History of fetal distress
Presentation (vertex, breech, transverse)
Vaginal or cesarean delivery (if cesarean, why?)
Use of forceps or vacuum extraction
Adaptation to extrauterine life Apgar scores
Resuscitation needed? If so, what and for how long?
Need for naloxone


Approach to Physical Examinations of the Newborn: When, Why, and How



The first examination


Every newborn infant should be examined at least twice during the first few days of life. An additional examination after discharge but within the first week is recommended, particularly if the mother and infant are discharged from the hospital prior to 48 hours postnatally. If possible, perform the first assessment in the hospital’s delivery area to (1) identify any obvious major and minor congenital malformations, (2) assess gestational age, nutritional status, and vigor, and (3) determine how well the baby handles the transition from intrauterine to extrauterine life.


Most babies make the major physiologic adaptations of this transition smoothly. The few who do not adapt normally—particularly those born prematurely or after perinatal stress or asphyxia—will need help to adapt successfully.



The method used almost universally in delivery rooms to evaluate the central nervous system (CNS) status and general adaptation of the neonate to extrauterine life is the Apgar score. This scoring system, summarized in Table 4–2, evaluates the baby in five different respects: heart rate, respiration, color, muscle tone, and reflex irritability (response to stimulation). These signs are usually evaluated at 1 minute and 5 minutes after birth. The Apgar score is the total of the baby’s scores for each of the five signs. To be consistent, have the Apgar score recorded by an experienced clinical observer whose principal responsibility is caring for and evaluating the baby. Because inter-observer variation in scoring may be considerable, experience is essential. Evaluate the signs at exactly 1 minute and 5 minutes to establish the score, especially in relation to muscle tone and reflex irritability. The latter is usually elicited by firmly stroking the sole of the foot; the appropriate response to this stimulation is a vigorous cry.



Recording the Apgar score serves two purposes. First, it ensures a careful evaluation of the baby during the immediate newborn period. Second, it helps to determine the presence and level of CNS depression and whether there is a need to continue resuscitation. In babies who need resuscitation, serial scores measured at 1, 2, 5, and even 10 minutes furnish a semi-quantitative method of recording recovery. The relationship between low Apgar scores and neurologic abnormality later in infancy is not reliable.


The Apgar scoring system produces more than just a number. The presence or absence of individual signs should tell you not just that an infant had an “Apgar 6” but that this score was assigned because certain functions were absent or suboptimal. For example, a baby with congenital neuromuscular disease may score well for heart rate, respiratory effort, and color but poorly for muscle tone and reflex irritability. A preterm infant scores lower than a full-term baby because an immature baby’s muscle tone is always less than that of a normal-term infant.


The accurate diagnosis of perinatal asphyxia is not easy and requires not only evaluation of the clinical condition at birth but also evaluation of umbilical cord arterial blood gases and subsequent clinical neurologic sequelae in the newborn period (hypoxic-ischemic encephalopathy). Low Apgar scores may be caused by many conditions affecting the baby, such as sepsis, neuromuscular disorders, and perinatal asphyxia.





The third examination


The main purposes of the third examination are to discover postnatally acquired problems, such as infection and excessive jaundice, and to detect any malformations that were not apparent at the first or second examination, such as some forms of congenital heart disease whose murmurs are not audible on the first day of life. In past years, the third examination often was performed at 3 or 4 days of age. The current trend toward early discharge of mothers and infants from the hospital means that discharge may occur as early as 24 hours after birth, and discharge is common by 48 hours after a normal vaginal delivery. Thus the third examination often takes place after the mother has been discharged from the hospital. Early hospital discharge guidelines now recommend assessment of a newborn by a health care provider within 72 hours of discharge. However, it is important that this third examination and assessment of the baby’s condition be carried out within the first week of life. The third examination may be performed by a physician or by an experienced nurse or midwife and may take place in the hospital, in the home, or at a clinic or office.


Initially, many of us learned how to perform a physical examination with cooperative adult patients, in whom it was easy to start at the top of the head and work downward in a systematic cephalocaudal manner. Because infants are not always cooperative, you must be prepared to examine a newborn infant thoroughly but to keep the sequence of procedures flexible. For example, if the baby is resting quietly, first listen to the heart and chest, then palpate the abdomen. Carry out other parts of the examinations when the baby is active, moving, or even crying, but be sure to examine all systems and record the findings systematically.



Clinical Observations and What They Mean


Encourage the parents to participate as much as possible in the examination by undressing the baby, holding the baby on the lap or the bed, and providing a stabilizing finger for the baby to grasp (Fig. 4–1). The first part of the examination is the most important. Do not touch the baby except to remove all clothing gently. You may wish to leave the diaper on until you are ready to examine the lower portion of the baby. The baby should be undressed, warm, and well illuminated and should be helped to feel stable and secure on the examining surface. Improving the baby’s stability and relaxation by letting him or her grasp the parent’s or your finger allows an immediate appreciation of the strength of the baby’s reflex grasp and reduces the tendency for instinctive startle reflexes that occur when the baby feels unstable and rolls on the examining surface.



The ideal time to examine a newborn is a couple of hours after a feeding, when the baby may not be too deeply asleep, as babies often are just after a feeding, nor awake and screaming, as they often are just before a feeding. Stand back and take a long hard look at the infant; educated observation often reveals far more than touching, poking, and kneading. While observing the newborn, answer the following questions:






5. What color is the baby’s skin? After the initial transition period immediately following birth, a normal baby’s skin is well oxygenated or pink. In babies of more pigmented races, the pinkness is best seen on the palms, lips, buccal mucosa, and conjunctivae. It is normal for babies to exhibit acrocyanosis (i.e., bluish or purplish color of the hands and feet). Parents may need reassurance that this appearance is entirely normal. The extremities may be somewhat mottled with a netlike pattern if they are cool (a condition known as cutis marmorata, literally, “marble skin”) (Fig. 4–2). Generalized mottling may signify acidosis or vascular instability. Another variation of skin color is the so-called harlequin color change, seen mostly in low-birth-weight infants, in which the skin is dark pink or reddish on the dependent half of the baby but the upper half appears comparatively pale, with the two colors sharply demarcated along the midline. This phenomenon is striking but has no pathologic significance. It also is important to note if the baby appears jaundiced; hyperbilirubinemia in the first 24 hours of life is always a cause for further investigations and consideration of treatment. It is important to note that visual examination of the skin may not detect jaundice in a baby with significantly pigmented skin.


Look for hematomas, hemangiomas, ecchymoses, and petechiae. The last can be associated with increased intravascular pressure during delivery, thrombocytopenia from the presence of platelet antibodies, or congenital infections. Cutaneous hemangiomas are often absent or minimally apparent at birth but develop and grow during the first weeks or months of life, only to regress spontaneously later. Ecchymoses may indicate more than usual trauma or an underlying coagulation disorder.


You can perform much of the newborn’s neurologic examination without touching the baby. Do all four extremities move equally and maintain a general posture of flexion, with alternating flexion and extension movements? The eyes should move if they are open, and the baby may exhibit sucking and tongue movements, yawning, facial grimacing, and spontaneous startle responses. The four most important parts of the neurologic assessment are:






A baby’s level of alertness varies with the time of day and the time of last feeding; normal newborns spend about 20 out of 24 hours asleep. Visual alertness is temporarily limited if erythromycin ointment has been instilled in the eyes as prophylaxis for gonococcal ophthalmia.





Primitive Reflexes


Many so-called primitive reflexes can be elicited that may already have been observed during the earlier part of the examination.








Weighing and Measuring


For the physician’s and the parents’ records, it is important to (1) measure the baby’s head circumference, length, and weight accurately and (2) assess the nutritional status. Measure the head circumference, preferably with a disposable tape measure, around the largest occipital-frontal diameter across the forehead, just above the eyes, and over the most prominent part of the occiput (Fig. 4–6). Head circumference normally measures 33 to 37 cm in a full-term infant. If a baby’s head circumference measures slightly above or below the normal for age, check the parents’ head circumferences before “pushing the panic button.” Benign familial megalencephaly, a normal variant, is the most common cause of a larger than average head. The condition can be verified by checking the head circumference of both parents. Megalencephaly is usually handed down by the father.


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Jul 3, 2016 | Posted by in PEDIATRICS | Comments Off on Evaluating the Newborn: Diagnostic Approach

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