Clinical rounds in the well-baby nursery: treating jaundiced newborns

Ten pearls (and pitfalls) in the management of the jaundiced newborn: Remember to take a history. Ask about jaundice in previous siblings and check family ethnicity. Don't ignore jaundice in the first 24 hours--it is considered pathologic until proven otherwise. Some normal infants may appear jaundiced and have a bilirubin level of 5 mg/dL at 23 hours and 59 minutes. On the other hand, a bilirubin level of 5 mg/dL at 10 hours is almost certainly pathologic. Use your judgment. Don't treat 35 to 37 week gestation infants as if they were full-term infants. Although these babies are cared for in well-baby nurseries and are generally treated like full-term infants, they are not full term. They are not as vigorous and do not nurse as well as full-term infants. Infants at 37 weeks gestation are four times more likely to have a serum bilirubin level greater than 13 mg/dL than those at 40 weeks gestation. Don't send 35-week gestation infants home before 48 hours. Document your assessment, particularly if the infant is being discharged early. Document the presence or absence of jaundice and its severity. A late rising bilirubin is typical of G6PD deficiency. Think about the ethnic background: G6PD deficiency is much more likely to occur in families from Greece, Turkey, Sardinia, and Nigeria, and particularly in Sephardic Jews from Iraq, Iran, Syria, and Kurdistan. Your practice may not contain many such families but remember in today's world of travel and intermarriage, etc, these genes are ubiquitous and the diagnosis of G6PD deficiency should always be considered in a newborn child with a significant elevation of bilirubin, particularly if it is a male and the rise in bilirubin is of late onset. Don't use homeopathic doses of phototherapy. As with any drug, phototherapy should be provided in a therapeutic dose (see above), but with the light sources commonly used, it is impossible to overdose the patient. Don't ignore a failure of response to phototherapy. If the bilirubin rises despite adequate phototherapy, there must be a reason. Consider the possibility of an unrecognized hemolytic process. Provide timely follow-up. Infants discharged (as most are) before 48 hours should be seen by a health-care professional within 2 to 3 days of discharge. Don't ignore prolonged jaundice. About one in three normal breast-fed infants still will be clinically jaundiced when they are 2 weeks old (two thirds will be biochemically jaundiced). These infants all have indirect hyperbilirubinemia. Occasionally, however, an infant with prolonged jaundice has direct hyperbilirubinemia. In these infants, the diagnosis of biliary atresia or some other cause of cholestatic jaundice must be considered. If the infant is clinically jaundiced beyond age 2 weeks, you should: 1) check the newborn record to make sure that the metabolic screen for hypothyroidism is normal (congenital hypothyroidism is a cause of indirect hyperbilirubinemia), and 2) ask the mother about the color of the urine and stool. If the baby's stools are pale or the urine is dark yellow, you must get a direct bilirubin to rule out cholestasis. If there is direct hyperbilirubinemia, a urine dipstick will identify the presence of bile (bilirubin). If the color of the urine and stool are normal (by history), it is reasonable to follow the child for another week. However, any infant who is still jaundiced beyond age 3 weeks must have a measurement of direct bilirubin. Don't ignore severe jaundice. If the bilirubin is sufficiently elevated, kernicterus can occur in a healthy, breast-fed infant.

Kernicterus in otherwise healthy, breast-fed term newborns

OBJECTIVE

To document the occurrence of classical kernicterus in full-term, otherwise healthy, breast-fed infants.

METHODS

We reviewed the files of 22 cases referred to us by attorneys throughout the United States during a period of 18 years, in which neonatal hyperbilirubinemia was alleged to be responsible for brain damage in apparently healthy, nonimmunized, full-term infants. To qualify for inclusion, these infants had to be born at 37 or more weeks' gestation, manifest the classic signs of acute bilirubin encephalopathy, and have the typical neurologic sequelae.

RESULTS

Six infants, born between 1979 and 1991, met the criteria for inclusion. Their peak recorded bilirubin levels occurred 4 to 10 days after birth and ranged from 39.0 to 49.7 mg/dL. All had one or more exchange transfusions. One infant had an elevated reticulocyte count (9%) but no other evidence of hemolysis. The other infants had no evidence of hemolysis, and no cause was found for the hyperbilirubinemia (other than breast-feeding).

CONCLUSIONS

Although very rare, classic kernicterus can occur in apparently healthy, full-term, breast-fed newborns who do not have hemolytic disease or any other discernible cause for their jaundice. Such extreme elevations of bilirubin are rare, and we do not know how often infants with similar serum bilirubin levels escape harm. We also have no reliable method for identifying these infants early in the neonatal period. Closer follow-up after birth and discharge from the hospital might have prevented some of these outcomes, but rare, sporadic cases of kernicterus might not be preventable unless we adopt an approach to follow-up and surveillance of the newborn that is significantly more rigorous than has been practiced. The feasibility, risks, costs, and benefits of this type of intervention need to be determined.

The effect of breast-feeding frequency on serum bilirubin levels

OBJECTIVE

Our purpose was to evaluate the effect of breast-feeding frequency on serum bilirubin levels in the first 3 days after birth.

STUDY DESIGN

Two hundred seventy-five infants were randomly assigned to a frequent or demand breast-feeding schedule.

RESULTS

Infants in the frequent group (n = 131) nursed nine (7.5 to 10.5) times per day (median and inner 80%), and the demand group (n = 143) fed 6.5 (5.5 to 8.0) times per day. The serum bilirubin level was measured in all infants between 48 and 80 hours (median 53 hours, inner 80% 48 to 68 hours) and was 7.4 (1.8 to 10.7) mg/dl in the frequent group and 8.0 (2.9 to 11.2) mg/dl in the demand group (p = 0.103). There was no correlation between the frequency of breast-feeding and the serum bilirubin level.

CONCLUSION

Within the range of the frequency of nursing observed in this study, we could not demonstrate a significant effect on serum bilirubin levels in the first 3 days after birth.

Hyperbilirubinemia in the breast-fed newborn: a controlled trial of four interventions

A controlled clinical trial was conducted to compare the effect of four different interventions on hyperbilirubinemia in 125 full-term breast-fed infants. Of 1685 term infants who met the inclusion criteria, 126 (7.4%) had a serum bilirubin concentration > or = 291 mumol/L (17 mg/dL). When the bilirubin reached this level, babies were assigned at random to one of four interventions: (1) continue breast-feeding and observe; (2) discontinue breast-feeding, substitute formula; (3) discontinue breast-feeding, substitute formula and administer phototherapy; (4) continue breast-feeding, administer phototherapy. The serum bilirubin concentration reached 342 mumol/L (20 mg/dL) in 24% of infants in group 1, 19% in group 2, 3% in group 3, and 14% in group 4. When phototherapy was used, the decline in serum bilirubin was significantly larger and more rapid (compared with no phototherapy). In the majority of breast-fed infants whose serum bilirubin levels reach 291 mumol/L (17 mg/dL) the bilirubin will decline spontaneously and will not reach 342 mumol/L (20 mg/dL). If the infant is significantly jaundiced and a decision is made to intervene, parents can be given a number of options and can make an informed decision regarding which, if any, intervention they prefer.

Double versus single phototherapy in low birth weight newborns

Conventional phototherapy systems that simultaneously irradiate the front and the back of the baby lower the serum bilirubin level more rapidly than one-sided systems, but they are impractical. Fiberoptic phototherapy makes it easy to administer conventional phototherapy from above while the infant lies on a fiberoptic phototherapy blanket. Newborns with birth weights less than 2500 g were randomly assigned to receive either single (n = 37) or double (n = 33) phototherapy. The groups were similar in clinical and laboratory characteristics. After 18 hours of therapy the serum bilirubin concentration declined by 31 +/- 11% in the double and 16 +/- 15% in the single phototherapy group (2.9 +/- 1.1 vs 1.6 +/- 1.4 mg/dL), and the difference in the total serum bilirubin levels after 18 hours of therapy was significant (double phototherapy group 7.1 +/- 2.7 mg/dL vs single phototherapy group 8.2 +/- 2.6 mg/dL). After 18 hours of treatment the serum bilirubin level was less than the phototherapy threshold level in 26 of 37 single phototherapy patients vs 32 of 33 double phototherapy patients. Double phototherapy was well tolerated. It is concluded that this type of double phototherapy is more effective than single phototherapy in low birth weight newborns. Double phototherapy may be useful when it is necessary to reduce an elevated serum bilirubin level as rapidly as possible or when the bilirubin level is rising with single phototherapy.

Risk of sepsis in newborns with severe hyperbilirubinemia

Because bacterial infection is a potential cause of hyperbilirubinemia, some authors suggest that newborns with significant unexplained indirect hyperbilirubinemia should be evaluated for sepsis. We reviewed the charts of 306 newborns admitted to a pediatric ward within 21 days of birth with a diagnosis of indirect hyperbilirubinemia (peak serum bilirubin level 316 +/- 48, range 217 to 498 mumol/L) (18.5 +/- 2.8, 12.7 to 29.1 mg/dL). Ninety percent were fully or partially breast-fed. Sepsis was identified in 0 of 306 newborns (upper 95% confidence limit for the risk of sepsis = 1%). The overwhelming majority of newborns who require readmission to hospital for indirect hyperbilirubinemia are healthy, breast-fed newborns and do not need to be investigated for sepsis. If indirect hyperbilirubinemia is ever the only manifestation of bacteremia or incipient sepsis, it must be a rare event.

Severe retinopathy of prematurity and steroid exposure

During a 3-year period (1988 through 1990) an increase was observed in the number of infants born at 23- to 26-weeks' gestation who required cryotherapy for severe retinopathy of prematurity (0/20, 1988; 3/14, 1989; 6/18, 1990; P = .015). Inasmuch as this was not related to improved survival, a retrospective case-control study was conducted to try to explain this observation. Of 52 surviving infants who had been born at 23 to 26 weeks' gestation, 9 required cryotherapy and the other 43 served as control subjects. There were no differences between groups in birthweight, gestational age, or the number of infants with hyaline membrane disease, intraventricular hemorrhage, or hydrocephalus. Factors related to the need for cryotherapy included patent ductus arteriosus (P = .046), mechanical ventilation for more than 21 days (P = .045), and the use of steroids for lung disease (P < .001). In this neonatal intensive care unit, steroids are administered according to the attending neonatologist's preference. Inasmuch as steroids are considered only for infants still ventilator dependent at 21 days, this group was analyzed separately (n = 36). Of the 21 factors examined, only the use of steroids for lung disease was associated with the need for cryotherapy (P < .001).

Evaluation and treatment of jaundice in the term newborn: a kinder, gentler approach

Standard recommendations for evaluating and treating jaundice in term babies include following all babies closely for jaundice, obtaining several laboratory tests in those with early jaundice or bilirubin levels more than 12 to 13 mg/dL (205 to 222 mumol/L), using phototherapy to try to keep bilirubin levels below 20 mg/dL (342 mumol/L), and doing exchange transfusions if phototherapy fails, regardless of the cause of the jaundice. These recommendations are likely to lead to unnecessary testing and treatment of many jaundiced term infants. Because most jaundiced infants have no underlying illness, and the generally recommended laboratory tests lack sensitivity and specificity, they are seldom useful. In most babies, the only blood tests needed to evaluate jaundice are the blood type and group (of baby and mother) and a direct Coombs' test. A determination of direct bilirubin level should be added if jaundice is prolonged (greater than 2 to 4 weeks) or the baby has other signs of illness. Bilirubin toxicity is rare in term babies without hemolysis. In this low-risk group, the risks and cost of identifying and treating high bilirubin levels may exceed the benefits. Such infants need not be closely followed for jaundice. If significant jaundice is nonetheless found, treatment should be deferred to relatively high levels of serum bilirubin, with a goal of keeping bilirubin levels below 400 to 500 mumol/L (23.4 to 29.2 mg/dL). Babies with hemolytic disease should be followed more closely, and their bilirubin levels kept below 300 to 400 mumol/L (17.5 to 23.4 mg/dL). These recommendations should be reevaluated as new data become available. In the meantime, currently available data justify an approach to the jaundiced term infant that is less aggressive than previously recommended.

A clinical trial of fiberoptic phototherapy vs conventional phototherapy

We conducted a randomized, controlled trial to compare fiberoptic phototherapy with conventional phototherapy in healthy jaundiced newborns with birth weights greater than 2500 g. Twelve patients received fiberoptic phototherapy and 14 patients received conventional phototherapy. There were no significant differences between the groups with respect to birth weight, gestational age, feeding method, presence of hemolytic disease, hematocrit, reticulocyte count, or initial serum bilirubin level. Measured irradiance at 425 to 475 nm for conventional phototherapy was greater than that of fiberoptic phototherapy (9.2 +/- 0.9 microW/cm2 per nanometer vs 8.2 +/- 1.2 microW/cm2 per nanometer). Both types of phototherapy lowered the level of serum bilirubin after 18 hours of therapy (fiberoptic group, from 231 +/- 29 to 210 +/- 24 mumol/L; conventional group, from 231 +/- 21 to 188 +/- 26 mumol/L), but the mean serum bilirubin level was lower after 18 hours of therapy in the conventional phototherapy group (188 +/- 26 vs 210 +/- 24 mumol/L). There were no side effects in either group of newborns. Both methods of phototherapy decreased the serum bilirubin level, but conventional phototherapy did so more effectively, probably because of its greater irradiance.

Does hyperbilirubinemia damage the brain of healthy full-term infants?

In the 1950s, exchange transfusion to keep the total serum bilirubin below 20 mg/dl was shown to be an effective way of preventing kernicterus in babies with erythroblastosis fetalis. For the last 15 to 20 years this level has also been used to determine the need for intervention in healthy full-term infants who do not have hemolytic disease. A critical review of all the available data including six studies from the collaborative perinatal project (more than 30,000 infants) and several smaller studies of term infants without hemolysis reveals essentially no evidence of adverse effects of bilirubin on IQ, neurologic examination, or hearing. The investigation and treatment of normal infants with jaundice is expensive and potentially harmful. We need to reassess our approach to hyperbilirubinemia in healthy full-term infants.

Regulation of oxygen concentration delivered to infants via nasal cannulas

The administration of oxygen to infants via nasal cannulas is now a common practice in neonatal units although the inspired oxygen concentration reaching the patient's airway is unknown. We measured the hypopharyngeal oxygen concentration in 10 infants who were receiving oxygen via nasal cannulas and assessed the impact of changes in the flow rate and inspired oxygen concentration. Weaning these infants by reducing the flow rate, even if changes are slight, produces clinically important changes in the oxygen concentration reaching the airway. Such changes are poorly tolerated by infants with chronic lung disease. Changing the flow rate and inspired oxygen concentration, rather than the flow rate alone, provides greater precision and is likely to avoid excessive and abrupt changes in the oxygen concentration reaching the airway.

Gastroesophageal reflux to the proximal esophagus in infants with bronchopulmonary dysplasia

Recurrent aspiration after gastroesophageal reflux (GER) may contribute to the severity of chronic lung disease. If so, it should be possible to document acid reflux to the proximal esophagus. Using an esophageal pH probe placed at the level of the first or second thoracic vertebra, we evaluated GER in 14 infants with bronchopulmonary dysplasia (BPD) and 13 infants without BPD. The infants with BPD had significantly less GER, as measured by the percentage of time the pH was less than 4 (3.26% +/- 7.05% vs 12.88% +/- 15.27% [mean +/- SD]), number of GER episodes per hour (0.46 +/- 0.66 vs 1.35 +/- 0.83), number of GER episodes lasting longer than 5 minutes per hour (0.10 +/- 0.23 vs 0.31 +/- 0.29), and longest GER episode (6.76 +/- 10.29 vs 26.66 +/- 38.30 minutes). Gastroesophageal reflux may be unimportant in infants with BPD, or even occasional episodes of GER may aggravate existing lung disease.

Preductal and postductal transcutaneous oxygen tension measurements in premature newborns with hyaline membrane disease

Pre- and postductal transcutaneous oxygen tension (tcPO2) was measured in 23 preterm infants with hyaline membrane disease to estimate the degree of right to left ductal shunting. The study was done during the first 24 hours of life and the data were recorded continuously. The studies were 11.9 +/- 4.0- hours long, (mean +/- SD) and the difference between the pre- and postductal tcPO2 (delta TcPO2) was measured every 100 seconds. Of 9,872 determinations, the delta tcPO2 was less than or equal to 15 mm Hg in 90.1%, 16 to 29 mm Hg in 9.3%, and greater than or equal to 30 mm Hg in 0.6%. It was concluded that large differences between pre- and postductal oxygen tension are rare in infants with hyaline membrane disease. The results of this and other published data suggest that it is unlikely that measurement of PaO2 in the descending aorta or tcPO2 below the ductus places infants at an increased risk of having retinopathy of prematurity develop.

Jaundice in the healthy newborn infant: a new approach to an old problem

We measured the serum bilirubin concentrations in 2,416 consecutive infants admitted to our well baby nursery. The maximal serum bilirubin concentration exceeded 12.9 mg/dL (221 mumol/L) in 147 infants (6.1%), and these infants were compared with 147 randomly selected control infants with maximal serum bilirubin levels less than or equal to 12.9 mg/dL. A serum bilirubin concentration greater than 12.9 mg/dL was associated strongly with breast-feeding (P = .0000) and percentage of weight loss after birth (P = .0001), as well as with maternal diabetes, oriental race, decreased gestational age, male sex, bruising, and induction of labor with oxytocin. Risk ratios and the risk of jaundice were calculated for hypothetical infants in the presence and absence of these variables. These calculations show that, in certain infants, "nonphysiologic" jaundice is likely to develop and its presence in such infants might not require laboratory investigations. In others, a modest degree of hyperbilirubinemia could be cause for concern. An awareness of these factors and their potential contribution to serum bilirubin levels permits a more rational approach to the action levels used for the investigation of jaundice in the newborn. We need a new definition of physiologic jaundice.

A comparison of the pupillary and cardiovascular effects of various mydriatic agents in preterm infants

We conducted a randomized, masked study of pupillary dilating capabilities and associated cardiovascular effects of three solutions. Thirty-four babies less than 1500 grams at birth were studied at six to eight weeks. Group A (n = 10) received phenylephrine (PE) 2.5% and tropicamide 1.0%; Group B (n = 10) PE 2.5%, tropicamide 0.5%, and cyclopentolate 0.5%, Group C (n = 10) PE 1.0% and tropicamide 1.0%; Group D (n = 4) saline 0.9%. One drop was placed in each eye and repeated five minutes later. Pupillary dilation was measured with a metric ruler by direct observation at one hour. Blood pressure (BP) and heart rate (HR) were monitored, using an oscillometer, immediately prior to the instillation of the drops and at five-minute intervals, for 60 minutes. BP and HR increased transiently in all groups receiving mydriatics but returned to baseline values in 25 minutes. This increase was significant in Groups A and B (2.5% PE: p less than 0.02). Group D (saline) showed no change in BP or HR. Postdrop pupillary size was largest in Group A but the differences were not significant. On exposure to bright light, the pupillary size in Group C was significantly smaller than Groups A or B (7.35 +/- 0.59 mm, 7.23 +/- 0.38 mm and 6.75 +/- 0.57 mm in Groups A, B and C, p less than .01). Nevertheless, dilation was sufficient to allow appropriate examination in all infants (pupillary diameter greater than 6.0 mm). Solutions containing 2.5% PE are most effective for use in LBW infants, but produce cardiovascular effects. Solutions containing 1% PE provide adequate dilation with minimum cardiovascular effects.