Clinical trial of tin mesoporphyrin to prevent neonatal hyperbilirubinemia

OBJECTIVE

To assess the efficacy of the heme oxygenase inhibitor, tin mesoporphyrin (SnMP), to reduce total bilirubin (TB) levels.

STUDY DESIGN

Masked, SnMP (4.5 mg kg(-1)), placebo-controlled, multicenter trial of single intramuscular injection to newborns ⩾35 weeks gestational age whose predischarge screening transcutaneous bilirubin (TcB) was >75th percentile.

RESULTS

Two hundred and thirteen newborns (median age 30 h) were randomized to treatment with SnMP (n=87) or 'sham' (n=89). We found that the duration of phototherapy was halved. Within 12 h of SnMP administration, the natural TB trajectory was reversed. At age 3 to 5 days, TB in the SnMP-treated group was +8% but sixfold lower than the 47% increase in the sham-treated group (P<0.001). At age 7 to 10 days, mean TB declined 18% (P<0.001) compared with a 7.1% increase among controls. No short-term adverse events from SnMP treatment were noted other than photoreactivity due to inadvertent exposure to white light phototherapy.

CONCLUSION

Early, predischarge SnMP administration decreased the duration of phototherapy, reversed TB trajectory and reduced the severity of subsequent hyperbilirubinemia.

Transcutaneous bilirubin levels in newborns <35 weeks' gestation

OBJECTIVE

In infants <35 weeks' gestation, we sought to define the transcutaneous bilirubin (TcB) levels at which a total serum bilirubin (TSB) level suggesting the need for phototherapy is unlikely to occur and a TSB measurement can, therefore, be avoided.

STUDY DESIGN

Nursing staff performed 896 TcB measurements within 1 h of a TSB on 225 neonates 26 0/7-34 6/7 weeks' postmenstrual age (PMA). Generalized linear models were fit with generalized estimating equations (GEEs) to model the probability of having a TSB level at or above the phototherapy initiation cutpoint as a function of the TcB; these methods allow for multiple tests per infant.

RESULTS

The mean difference between TcB and TSB measurements was <1 mg dl(-1) for each PMA category. When the TcB was at least 3 mg dl(-1) below the TSB cutpoint for phototherapy, there was a ⩾98% probability that the TSB was not at, or above, the recommended phototherapy level. The single exception to this was a phototherapy level of 6 mg dl(-1) for infants of 28 0/7-29 6/7 weeks' PMA, where a TcB of 4 mg dl(-1) below the phototherapy level (ie a TcB ⩽2 mg dl(-1)) was necessary to achieve ⩾98% probability.

CONCLUSION

Our data support the use of routine TcB screening for infants 28-34 6/7 weeks' gestation. TcB screening in the neonatal intensive care unit can identify infants who require a TSB to confirm or exclude the need for phototherapy.

Routine transcutaneous bilirubin measurements combined with clinical risk factors improve the prediction of subsequent hyperbilirubinemia

OBJECTIVE

To evaluate predischarge transcutaneous bilirubin (TcB) measurements combined with risk factors as predictors of the risk of a subsequent total serum bilirubin (TSB) >or=17 mg per 100 ml (291 micromol l(-1)).

STUDY DESIGN

Routine TcB measurements are obtained daily for all infants in our well baby nursery. We performed a nested case-control study comparing all 75 infants who had been readmitted with TSB >or=17 mg per 100 ml (291 micromol l(-1)) between 1 February 2005 and 28 February 2007 with randomly selected controls that had not been readmitted.

RESULT

Between 1 February 2005 and 28 February 2007, 11 456 infants were discharged from the well baby nursery. Seventy-five infants (0.65%) were readmitted at a mean age of 110+/-29.9 h with a TSB>or=17 mg per 100 ml (291 micromol l(-1)). All received phototherapy. Using logistic regression analysis, three variables were statistically significant for predicting cases: the maximum predischarge TcB percentile group (P<0.0001, adjusted odds ratio (AOR), >95th percentile 148; 95% confidence interval (CI) 21 to >999, AOR 76 to 95th percentile 15; 95% CI 3.1 to 70, AOR 50 to 75th percentile 6.1; 95% CI 1.3 to 28 compared with <50th percentile), exclusive breastfeeding (P<0.0001, AOR 11; 95% CI 3.7 to 34) and gestational age (P=0.0057, AOR 35 to 36 6/7 week 21; 95% CI 2.3 to 185, AOR 37 to 37 6/7 week 15; 95% CI 1.9 to 115, AOR 38 to 38 6/7 week 1.8; 95% CI 0.3 to 11, AOR 39 to 39 6/7 week 1.1; 95% CI 0.2 to 7 AOR >or=41 week 0.88; 95% CI 0.1 to 10 compared with 40 to 40 6/7 week infants). These three variables provided the best prediction of a case (c=0.885, area under the receiver operating characteristic curve) and this prediction was significantly better than the use of the clinical risk factors, gestation and exclusive breastfeeding, alone (c=0.770, P<0.001) or the TcB percentile grouping alone (c=0.766, P<0.001). Substituting the TcB rate of rise (c=0.903, P=0.316) or the last measured TcB (c=0.873, P=0.292) for the maximum TcB measurement did not significantly improve the predictors of a case.

CONCLUSION

Combining predischarge TcB levels with two clinical risk factors-gestational age and exclusive breastfeeding-significantly improves the prediction of subsequent hyperbilirubinemia.

Randomized controlled trial of light-emitting diode phototherapy

OBJECTIVE

We wished to compare the efficacy of light-emitting diode (LED) phototherapy with special blue fluorescent (BB) tube phototherapy in the treatment of neonatal hyperbilirubinemia.

STUDY DESIGN

We randomly assigned 66 infants >or=35 weeks of gestation to receive phototherapy using an LED device or BB. In addition to phototherapy from above, all infants also received phototherapy from below using four BB tubes or a fiberoptic pad.

RESULT

After 15+/-5 h of phototherapy, the rate of decline in the total serum bilirubin (TSB) was 0.35+/-0.25 mg/dl/h in the LED group vs 0.27+/-0.25 mg/dl/h in the BB group (P=0.20).

CONCLUSION

LED phototherapy is as effective as BB phototherapy in lowering serum bilirubin levels in term and near-term newborns.

Does intensive phototherapy produce hemolysis in newborns of 35 or more weeks gestation?

OBJECTIVE

Because there is some in vivo and in vitro evidence that standard phototherapy might produce hemolysis, we wished to know whether intensive phototherapy produces hemolysis.

STUDY DESIGN

We measured end-tidal carbon monoxide (CO) concentration corrected for ambient CO (ETCOc) in 27 newborn infants > or =35 weeks gestation receiving intensive phototherapy (average irradiance 43 microW/cm2/nm).

RESULTS

There was a steady decrease in the mean ETCOc over the course of the phototherapy.

CONCLUSION

Intensive phototherapy did not produce hemolysis in infants > or =35 weeks gestation.

Jaundice in low birthweight infants: pathobiology and outcome

Jaundice in preterm, as well as full term, infants results from (a) an increased bilirubin load in the hepatocyte, (b) decreased hepatic uptake of bilirubin from the plasma, and/or (c) defective bilirubin conjugation. Hyperbilirubinaemia in preterm infants is more prevalent, more severe, and its course more protracted than in term neonates.

Treatment of jaundice in low birthweight infants

Exchange transfusion and phototherapy remain the staples of intervention for the jaundiced newborn. Clinical management of the jaundiced low birthweight infant is discussed.

The Bloxsom air lock: a historical perspective

In 1950, Allan P. Bloxsom (1901-1991), a pediatrician at the St Joseph Hospital in Houston, introduced his positive pressure oxygen air lock (AL) for the delivery room resuscitation of the asphyxiated newborn. The infant's entire body was placed into a cylindrical steel chamber that was tightly sealed and infused with warmed humidified 60% oxygen. The positive pressure within the AL was cycled between 1 and 3 lb/in(2) at 1-minute intervals to simulate the intrauterine pressures during the second stage of labor. Bloxsom developed the AL device in response to his hypothesis that the contractions of labor help to "condition: the infant for extrauterine survival. Parmalee said that the AL "certainly locks the infant up, safe from meddlesome and unintelligent treatment." When clear plastic versions of the AL became commercially available, it received widespread use in delivery rooms and newborn nurseries throughout the United States. In 1953, Apgar and Kreiselman produced apnea in adult dogs using pentobarbital and a muscle relaxant, and found that the AL device was unsuccessful with the oxygenation and ventilation of the animals. In 1954, Townsend in Rochester, New York, reported on his experience with the AL in 150 premature infants. He concluded that the AL should be "more accurately referred to as an oxygenator" and that, "the truly apneic infant cannot be maintained in a acyanotic state by the AL." The AL was finally subjected to the scrutiny of a randomized, controlled clinical trial that was published in 1956. Reichelderfer and Nitowski at Johns Hopkins randomized 171 infants to receive care in the AL or in an Isolette. Routine resuscitation, including positive pressure ventilation, was administered, as needed, to both study groups before placement into the AL or Isolette (Air Shields Inc, Hatboro, PA). They did not find any differences in the outcomes of the 2 study groups. By the mid 1950s, new information linking oxygen therapy and retrolental fibroplasia, led to a rapid decline in the use of the AL, even before the publication of the randomized trial.

Phototherapy--traditional and nontraditional

An observation by an English nurse in 1956 led to the discovery that visible light could lower serum bilirubin levels in newborn infants, and subsequent research showed how photons of light energy are absorbed by the bilirubin molecule converting it into isomers that are readily excreted by the liver and the kidney. Understanding the dose-response effect and other factors that influence the way light works to lower bilirubin levels has led to the effective use of phototherapy and has eliminated the need for exchange transfusion in almost all jaundiced infants.

Prediction of hyperbilirubinemia in near-term and term infants

OBJECTIVE

The purpose of this study was to determine whether end-tidal carbon monoxide (CO) corrected for ambient CO (ETCOc), as a single measurement or in combination with serum total bilirubin (STB) measurements, can predict the development of hyperbilirubinemia during the first 7 days of life.

METHODS

From nine multinational clinical sites, 1370 neonates completed this cohort study from February 20, 1998 through February 22, 1999. Measurements of both ETCOc and STB were performed at 30+/-6 hours of life; STB also was measured at 96+/-12 hours and subsequently following a flow diagram based on a table of hours of age-specific STB. An infant was defined as hyperbilirubinemic if the hours of age-specific STB was greater than or equal to the 95th percentile as defined by the table at any time during the study.

RESULTS

A total of 120 (8.8%) of the enrolled infants became hyperbilirubinemic. Mean STB in breast-fed infants was 8.92+/-4.37 mg/dl at 96 hours versus 7.63+/-3.58 mg/dl in those fed formula only. The mean ETCOc at 30+/-6 hours for the total population was 1.48+/-0.49 ppm, whereas those of nonhyperbilirubinemic and hyperbilirubinemic infants were 1.45+/-0.47 and 1.81+/-0.59 ppm, respectively. Seventy-six percent (92 of 120) of hyperbilirubinemic infants had ETCOc greater than the population mean. An ETCOc greater than the population mean at 30+/-6 hours yielded a 13.0% positive predictive value (PPV) and a 95.8% negative predictive value (NPV) for STB > or =95th percentile. When infants with STB > or =95th percentile at <36 hours of age were excluded, the STB at 30+/-6 hours yielded a 16.7% PPV and a 98.1% NPV for STB >75th percentile. The combination of these two measurements at 30+/-6 hours (either ETCOc more than the population mean or STB >75th percentile) had a 6.4% PPV with a 99.0% NPV.

CONCLUSIONS

This prospective cohort study supports previous observations that measuring STB before discharge may provide some assistance in predicting an infant's risk for developing hyperbilirubinemia. The addition of an ETCOc measurement provides insight into the processes that contribute to the condition but does not materially improve the predictive ability of an hours of age-specific STB in this study population. The combination of STB and ETCOc as early as 30+/-6 hours may identify infants with increased bilirubin production (eg, hemolysis) or decreased elimination (conjugation defects) as well as infants who require early follow-up after discharge for jaundice or other clinical problems such as late anemia. Depending on the incidence of hyperbilirubinemia within an institution, the criteria for decision making should vary according to its unique population.

Prediction of hyperbilirubinemia in near-term and term infants

OBJECTIVE

The purpose of this study was to determine whether end-tidal carbon monoxide (CO) corrected for ambient CO (ETCOc), as a single measurement or in combination with serum total bilirubin (STB) measurements, can predict the development of hyperbilirubinemia during the first 7 days of life.

METHODS

From 9 multinational clinical sites, 1370 neonates completed this cohort study from February 20, 1998, through February 22, 1999. Measurements of both ETCOc and STB were performed at 30 +/- 6 hours of life; STB also was measured at 96 +/- 12 hours and subsequently following a flow diagram based on a table of hours of age-specific STB. An infant was defined as hyperbilirubinemic if the hours of age-specific STB was greater than or equal to the 95th percentile as defined by the table at any time during the study.

RESULTS

A total of 120 (8.8%) of the enrolled infants became hyperbilirubinemic. Mean STB in breastfed infants was 8.92 +/- 4.37 mg/dL at 96 hours versus 7.63 +/- 3.58 mg/dL in those fed formula only. The mean ETCOc at 30 +/- 6 hours for the total population was 1.48 +/- 0.49 ppm, whereas those of nonhyperbilirubinemic and hyperbilirubinemic infants were 1.45 +/- 0.47 ppm and 1.81 +/- 0.59 ppm, respectively. Seventy-six percent (92 of 120) of hyperbilirubinemic infants had ETCOc greater than the population mean. An ETCOc greater than the population mean at 30 +/- 6 hours yielded a 13.0% positive predictive value (PPV) and a 95.8% negative predictive value (NPV) for STB >/=95th percentile. When infants with STB >95th percentile at <36 hours of age were excluded, the STB at 30 +/- 6 hours yielded a 16.7% PPV and a 98.1% NPV for STB >75th percentile. The combination of these 2 measurements at 30 +/- 6 hours (either ETCOc more than the population mean or STB >75th percentile) had a 6.4% PPV with a 99.0% NPV. Conclusions. This prospective cohort study supports previous observations that measuring STB before discharge may provide some assistance in predicting an infant's risk for developing hyperbilirubinemia. The addition of an ETCOc measurement provides insight into the processes that contribute to the condition but does not materially improve the predictive ability of an hours of age-specific STB in this study population. The combination of STB and ETCOc as early as 30 +/- 6 hours may identify infants with increased bilirubin production (eg, hemolysis) or decreased elimination (conjugation defects) as well as infants who require early follow-up after discharge for jaundice or other clinical problems such as late anemia. Depending on the incidence of hyperbilirubinemia within an institution, the criteria for decision making should vary according to its unique population.

Less aggressive treatment of neonatal jaundice and reports of kernicterus: lessons about practice guidelines

The publication of guidelines calling for less aggressive treatment of jaundice in newborns has been followed by a reappearance of case reports of kernicterus. These case reports illustrate important issues for writers and consumers of practice guidelines. One issue is the particular salience of identified patients with bad outcomes, and their potentially disproportionate influence on decision-makers. A second issue is whether, when good evidence of treatment benefit is lacking, policymakers should recommend what has traditionally been done, recommend less treatment, or not make recommendations at all. Finally, the cases raise the question of whether treatment guidelines should be more conservative than their authors actually believe is necessary, to take into account the likelihood that they will not be closely followed. We believe that case reports can serve as an important early warning system, but policymakers should be aware of their potentially disproportionate influence. In the long run, patients and clinicians will be best served by guidelines that summarize and acknowledge the limitations of existing evidence, that allow a wide range of treatment options when evidence is weak, and that recommend what the guideline authors actually believe should be done. In the short run a period of readjustment may be required, however, as clinicians become accustomed to guidelines written to be followed, rather than bent.

Changing partners: the dance of infant formula changes

The purpose of the study was to establish the frequency of, reasons for, and outcome of formula changes in infants. In this survey, we interviewed a convenience sample of 100 parents in our pediatric outpatient clinic and 75 parents in private pediatric office practices regarding their baby's initial formula, changes in formula, age at change, reason for change, initiator of the change, and outcome. The infants were 30-210 days old. Sixteen of the 175 infants (9%) were started on nonstandard formulas at birth. Fifty-eight of the remaining 159 infants (36%) were changed from regular to nonstandard formulas. After using nonstandard formulas, only seven infants (4%) were ever challenged subsequently with regular formula and all did well. Colic and regurgitation were the main reasons for switching formulas. In 47% the decision to change the formula was made by the mother and in 44% by the pediatrician. Following the formula change, mothers reported improvement or complete resolution of symptoms in 80% of infants. Although published estimates of formula intolerance range from 2% to 7.5%, one in three infants experiences a formula change, suggesting that nonstandard formulas are used excessively by both mothers and physicians. Nevertheless, in the vast majority of cases, parents report that the changes result in improvement or resolution of symptoms. Thus, while this practice appears to be a simple and effective intervention, it produces a significant population of soy and other nonstandard formula-fed babies who should be drinking regular formulas. Such changes encourage a belief by parents that their infants are allergic or otherwise abnormal and could have a negative impact on subsequent child development.

Bilirubin levels and severe retinopathy of prematurity in infants with estimated gestational ages of 23 to 26 weeks

Oxidative injury may contribute to the development of retinopathy of prematurity (ROP), and bilirubin may be a physiologically important antioxidant. Therefore we evaluated the relationship of ROP to bilirubin levels in 157 infants born at 23 to 26 weeks estimated gestational age. We found no definite association between bilirubin levels and severe ROP.

Capillary refill time in the hands and feet of normal newborn infants

We measured capillary refill time (CRT) in a convenience sample of 137 healthy newborns between 1 and 120 hours of age and 36-42 weeks gestation in the well-baby nursery of a large community hospital. CRT was measured by applying moderate pressure to the dorsum of the right hand and right foot for 5 seconds. Pressure was released and the time for complete refilling of the blanched area noted. Each infant was studied only once. We also measured ambient temperature and the skin temperature of the dorsum of the hand and foot and tested interobserver agreement. Mean CRT was 4.23 +/- 1.47 s (SD) range 1.63-8.78 s) in the hand and 4.64 +/- 1.41 s (range 2.15-9.94 s) in the foot (p = 0.0001) and did not change significantly in the first 72 hours. CRT decreased with increasing temperature. Environmental temperature, axillary temperature, and temperature of the hand and foot were all significantly and indirectly related to CRT, the strongest relationship existing between CRT and the skin temperature of the hand (r = -0.59, 95% CI -0.69, -0.47 p < 0.00001) and foot (r = -0.33, 95% CI -0.46, -0.16 p < 0.0001). With triplicate measurements, there was a statistically significant, but clinically moderate, order effect, CRT decreasing with each successive measurement (p < 0.0001). Interobserver agreement was fair, the correlation coefficient (r) ranged from 0.47 to 0.71. We conclude that CRT as measured in the hand or foot of a newborn infant in the first 5 days of life is a relatively subjective measurement with an endpoint that is not easy to define and a wide range of values in normal infants. It is influenced significantly by environmental, axillary, and skin temperatures. Since there is no accepted standard for measuring decreased perfusion in the newborn, it is impossible to document the clinical utility of CRT in this population. Further studies are necessary before CRT can be accepted as a useful measure of peripheral perfusion and circulatory status in the newborn infant.

Jaundice in full-term and near-term babies who leave the hospital within 36 hours. The pediatrician's nemesis

There has been an increase in hyperbilirubinemia in the newborn population and, perhaps, an increase in bilirubin encephalopathy. The early discharge of newborns from hospital has made it necessary for us to reorient our thinking about bilirubin levels in the first 24 to 48 hours of life and alter our approach to follow-up. The pediatrician must evaluate and follow infants who have risk factors for the development of severe hyperbilirubinemia, paying particular attention to the breast-feeding, near-term infant.

Length of stay, jaundice, and hospital readmission

OBJECTIVE

To evaluate the effect of postnatal age at the time of discharge on the risk of readmission to hospital with specific reference to readmission for hyperbilirubinemia.

DESIGN

Case-control study based on chart review.

SETTING

Large suburban community hospital in southeastern Michigan, delivering more than 5000 infants annually.

PATIENTS

Newborn infants, born between December 1, 1988, and November 30, 1994, who were readmitted to hospital within 14 days of discharge, were compared with a randomly selected control group who were not readmitted.

RESULTS

Of 29,934 infants discharged, 247 (0.8%) were readmitted by the age of 14 days. One hundred twenty-seven (51%) were admitted because of hyperbilirubinemia and 74 (30%) with the diagnosis of "rule out sepsis." The factors associated with an increased risk of readmission to the hospital were: infant of diabetic mother [odds ratios (OR), 3.45; 95% confidence limits (CL), 1.39 to 8.60]; gestation < or = 36 weeks (OR, 4.56; CL, 1.45 to 14.33), and 37 1/7 to 38 weeks (OR, 2.95; CL, 1.63 to 5.35) versus > or = 40 weeks; presence of jaundice in the nursery (OR, 1.73; CL, 1.14 to 2.63); breastfeeding (OR, 1.78; CL, 1.13 to 2.81); male sex (OR, 1.58; CL, 1.07 to 2.34); length of stay < 48 hours (OR, 1.91; CL, 1.15 to 3.16) and 48 to < 72 hours (OR, 2.09; CL, 1.25 to 3.50) versus > or = 72 hours. Factors associated with readmission for jaundice were gestation < or = 36 weeks (OR, 13.2; CL, 2.70 to 64.6), 36 1/7 to 37 weeks (OR, 7.7; CL, 2.69 to 22.0), 37 1/7 to 38 weeks (OR, 7.2; CL, 3.05 to 16.97) versus > or = 40 weeks; jaundice during nursery stay (OR, 7.80; CL, 3.38 to 18.0); length of stay < 48 hours (OR, 2.40; CL, 1.09 to 5.30) and 48 to < 72 hours (OR, 3.15; CL, 1.40 to 7.09) versus > or = 72 hours; male sex (OR, 2.89; CL, 1.46 to 5.74); and breastfeeding (OR, 4.21; CL, 1.80 to 9.87). Infants whose length of stay was < 48 hours were at no greater risk for readmission for jaundice or other causes than those whose length of stay was > or = 48 hours to < 72 hours.

CONCLUSIONS

Discharge at any time < 72 hours significantly increases the risk for readmission to hospital and the risk for readmission with hyperbilirubinemia when compared with discharge after 72 hours. The American Academy of Pediatrics recommends that infants discharged < 48 hours should be seen by a health care professional within 2 to 3 days of discharge. Our observations, as well as those of others, suggest that this recommendation should also be extended to those discharged at < 72 hours after birth. One approach to decreasing the risk of morbidity and readmission, particularly from hyperbilirubinemia, would be to help mothers to nurse their infants more effectively from the moment of birth.

Early discharge from the newborn nursery-effect on scheduling of follow-up visits by pediatricians

OBJECTIVE

To evaluate the impact of shorter hospital stays on the follow-up scheduling of newborn infants by private pediatricians.

DESIGN

Five surveys over a period of 18 months with educational intervention.

SETTING

Large community hospital well baby nursery.

PARTICIPANTS

Twenty private pediatricians who cared for at least 20 newborn infants in the well baby nurseries during 1995.

INTERVENTION

Oral and written communications to pediatricians emphasizing the importance of evaluating infants within 2 to 3 days of discharge if the hospital stay was less than 48 hours.

MAIN OUTCOME MEASURE

Interval between discharge from the nursery and the scheduled follow-up visit to the pediatrician.

RESULTS

In the first two surveys (September 1994 and March 1995) there was no significant difference in follow-up scheduling by pediatricians for those infants discharged <48 hours vs >/=48 hours. Differences were significant in July and November 1995, and in the final survey in March 1996. Nevertheless, in March 1996, 38% of short-stay infants were scheduled to be seen 4 or more days after discharge, and 33% 14 days after discharge.

CONCLUSION

Although follow-up practices have changed in response to shorter newborn hospital stays, a significant proportion of pediatricians are not following the American Academy of Pediatrics guidelines for the follow-up of short-stay infants. Whether or not failure to follow these guidelines will lead to an increase in morbidity is unknown.

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.