Examen fisico del rn

Clinics in Family Practice
Volume 5 • Number 2 • June 2003
Copyright © 2003 W. B. Saunders Company

MEDICAL CONCERNS IN THE NEONATAL PERIOD

Chika Akera, MD *
Sarah Ro, MD
[pic]
From the Department of Community and Family Medicine
Duke University
North Carolina, USA
The newborn examination, performed 2 to 3 times before the infant is discharged and again within a few days of life inthe office, may reveal significant medical stigmata.

BIRTH WEIGHT

High or low birth weight may be associated with certain conditions that deserve further investigation. Small for gestational age, defined as being below the 10th percentile, can be symmetric or asymmetric. Symmetric growth, where the head and body are smaller than expected, may indicate a condition that affected the fetusthroughout gestation, such as maternal substance use (eg, tobacco, alcohol, heroin, methadone), trisomy, or phenylketonuria [1] . In contrast, asymmetric growth retardation, where the head is spared, often indicates terminal uteroplacental insufficiency, such as maternal pregnancy-induced hypertension [1] . These babies tend to have polycythemia and thus hyperviscosity, which puts them at increasedrisk of asphyxia [1] . They are also at risk for hypoglycemia due to relatively decreased peripheral glycogen and fat stores. Large for gestational age infants (above the 90th percentile) have increased risk of birth injuries (eg, clavicle fracture, Erb palsy, asphyxia) [1] . The most common etiology is maternal diabetes or glucose intolerance [1] . When the constant glucose supply from the umbilicalcord is disrupted, these babies often become hypoglycemic [2] .

HEAD/EYES

The head should be examined for size and shape. Although microcephaly and macrocephaly can be associated with certain syndromes, head size is often hereditary. Causes of microcephaly include trisomy 18, trisomy 21, Cri-du-chat, cytomegalovirus (CMV), rubella, toxoplasmosis, and fetal alcohol syndrome (FAS) [3] .Macrocephaly may be seen in hydrocephalus or achondroplasia [1] . After a prolonged labor, an infant may develop caput succedaneum, a diffuse swelling superficial to the periosteum. This resolves within a few days, and parents should be reassured [1] . Infrequently, an infant may develop a cephalohematoma after a long labor or surgical vaginal delivery [1] . The blood vessels within the periosteum aredisrupted, and swelling does not cross suture lines. In this group of infants, the clinician should consider x-rays to evaluate for skull fracture [1] . Craniosynostosis may also present abnormal skull shapes, depending on which sutures fuse prematurely.
The absence of red light reflex should prompt further investigation. Congenital cataracts occur in 4 out of 1000 newborns [1] . In these cases,one should screen for TORCH (toxoplasmosis, other viruses, rubella, CMV, herpes simplex viruses) infections [1] . Unless corrected, these infants can develop deprivation amblyopia [3] . Retinoblastoma can also produce an abnormal red light reflex but is typically not diagnosed until age 1 or later [4] . In one study, diagnosis in a newborn was most often made after referral for positive familyhistory (67%), not after physical examination findings like leukocoria (13%) or other abnormalities (20%) [4] .

FACE

Cleft lip and palate are the most common congenital deformity of the head and neck. The incidence varies widely based on race: 1/1000 Caucasian births, 2/1000 Asian births, and 0.41/1000 African American births [5] . Approximately 60% to 80% of children born with cleft lip andpalate are male. Environmental agents, such as phenytoin and smoking, are associated with an increased incidence of cleft lip [6] . Genetic factors also play a role. Clefts of the secondary palate alone are associated with genetic syndromes compared with clefts involving the lip alone or clefts of the lip and palate [7] .
Feeding and airway compromise pose the most immediate problems in an infant...