Neonatal jaundice and diet

Molecular Physiology and Pathophysiology of Bilirubin Handling by the Blood, Liver, Intestine, and Brain in the Newborn

Bilirubin is the end product of heme catabolism formed during a process that involves oxidation-reduction reactions and conserves iron body stores. Unconjugated hyperbilirubinemia is common in newborn infants, but rare later in life. The basic physiology of bilirubin metabolism, such as production, transport, and excretion, has been well described. However, in the neonate, numerous variables related to nutrition, ethnicity, and genetic variants at several metabolic steps may be superimposed on the normal physiological hyperbilirubinemia that occurs in the first week of life and results in bilirubin levels that may be toxic to the brain. Bilirubin exists in several isomeric forms that differ in their polarities and is considered a physiologically important antioxidant. Here we review the chemistry of the bilirubin molecule and its metabolism in the body with a particular focus on the processes that impact the newborn infant, and how differences relative to older children and adults contribute to the risk of developing both acute and long-term neurological sequelae in the newborn infant. The final section deals with the interplay between the brain and bilirubin and its entry, clearance, and accumulation. We conclude with a discussion of the current state of knowledge regarding the mechanism(s) of bilirubin neurotoxicity.

Earlier Nutrient Fortification of Breastmilk Fed LBW Infants Improves Jaundice Related Outcomes

This study aimed to evaluate jaundice outcomes of low-birthweight premature infants commenced on earlier versus later nutrient supplementation (80 mL/kg/day vs. 160 mL/kg/day; total fluid intake, F80 vs. F160). Demographics, feeding regimens, and clinical outcomes data were collected. Infant and maternal characteristics were similar. Earlier nutrient supplementation was associated with multiple improved jaundice outcomes: total (TSBR), unconjugated and conjugated (CSBR) serum bilirubin values (196 ± 46 vs. 228 ± 52, 184 ± 44 vs. 212 ± 50, 12 ± 4 vs. 16 ± 5, respectively, all p < 0.001); phototherapy (39% vs. 64%, p < 0.0001). % CSBR/TSBR ratio was similar between groups. For those on phototherapy, duration and median irradiance were similar. F80 infants experienced reduced: feeding intolerance (26.0% vs. 45.2%, p = 0.007); length of stay (16.0 ± 0.64 vs. 18.8 ± 0.74 days, p = 0.03), maximum weight loss as % birth weight (5% vs. 6%, p = 0.03); decrease in weight Z-score at 10 days (-0.70 ± 0.03 vs. -0.79 ± 0.03, p = 0.01). F80 infants regained birthweight earlier (10.0 ± 0.3 days vs. 11.5 ± 0.3 days, p < 0.0001) and had no differences in adverse clinical outcomes. We speculate that earlier nutrient supplementation improved jaundice outcomes due to enhanced excretion/elimination of bilirubin.

Fluid supplementation for neonatal unconjugated hyperbilirubinaemia

BACKGROUND

Neonatal hyperbilirubinaemia is a common problem which carries a risk of neurotoxicity. Certain infants who have hyperbilirubinaemia develop bilirubin encephalopathy and kernicterus which may lead to long-term disability. Phototherapy is currently the mainstay of treatment for neonatal hyperbilirubinaemia. Among the adjunctive measures to compliment the effects of phototherapy, fluid supplementation has been proposed to reduce serum bilirubin levels. The mechanism of action proposed includes direct dilutional effects of intravenous (IV) fluids, or enhancement of peristalsis to reduce enterohepatic circulation by oral fluid supplementation.

OBJECTIVES

To assess the risks and benefits of fluid supplementation compared to standard fluid management in term and preterm newborn infants with unconjugated hyperbilirubinaemia who require phototherapy.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 5), MEDLINE via PubMed (1966 to 7 June 2017), Embase (1980 to 7 June 2017), and CINAHL (1982 to 7 June 2017). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included randomised controlled trials that compared fluid supplementation against no fluid supplementation, or one form of fluid supplementation against another.

DATA COLLECTION AND ANALYSIS

We extracted data using the standard methods of the Cochrane Neonatal Review Group using the Covidence platform. Two review authors independently assessed the eligibility and risk of bias of the retrieved records. We expressed our results using mean difference (MD), risk difference (RD), and risk ratio (RR) with 95% confidence intervals (CIs).

MAIN RESULTS

Out of 1449 articles screened, seven studies were included. Three articles were awaiting classification, among them, two completed trials identified from the trial registry appeared to be unpublished so far.There were two major comparisons: IV fluid supplementation versus no fluid supplementation (six studies) and IV fluid supplementation versus oral fluid supplementation (one study). A total of 494 term, healthy newborn infants with unconjugated hyperbilirubinaemia were evaluated. All studies were at high risk of bias for blinding of care personnel, five studies had unclear risk of bias for blinding of outcome assessors, and most studies had unclear risk of bias in allocation concealment. There was low- to moderate-quality evidence for all major outcomes.In the comparison between IV fluid supplementation and no supplementation, no infant in either group developed bilirubin encephalopathy in the one study that reported this outcome. Serum bilirubin was lower at four hours postintervention for infants who received IV fluid supplementation (MD -34.00 μmol/L (-1.99 mg/dL), 95% CI -52.29 (3.06) to -15.71 (0.92); participants = 67, study = 1) (low quality of evidence, downgraded one level for indirectness and one level for suspected publication bias). Beyond eight hours postintervention, serum bilirubin was similar between the two groups. Duration of phototherapy was significantly shorter for fluid-supplemented infants, but the estimate was affected by heterogeneity which was not clearly explained (MD -10.70 hours, 95% CI -15.55 to -5.85; participants = 218; studies = 3; I² = 67%). Fluid-supplemented infants were less likely to require exchange transfusion (RR 0.39, 95% CI 0.21 to 0.71; RD -0.01, 95% CI -0.04 to 0.02; participants = 462; studies = 6; I² = 72%) (low quality of evidence, downgraded one level due to inconsistency, and another level due to suspected publication bias), and the estimate was similarly affected by unexplained heterogeneity. The frequencies of breastfeeding were similar between the fluid-supplemented and non-supplemented infants in days one to three based on one study (estimate on day three: MD 0.90 feeds, 95% CI -0.40 to 2.20; participants = 60) (moderate quality of evidence, downgraded one level for imprecision).One study contributed to all outcome data in the comparison of IV versus oral fluid supplementation. In this comparison, no infant in either group developed abnormal neurological signs. Serum bilirubin, as well as the rate of change of serum bilirubin, were similar between the two groups at four hours after phototherapy (serum bilirubin: MD 11.00 μmol/L (0.64 mg/dL), 95% CI -21.58 (-1.26) to 43.58 (2.55); rate of change of serum bilirubin: MD 0.80 μmol/L/hour (0.05 mg/dL/hour), 95% CI -2.55 (-0.15) to 4.15 (0.24); participants = 54 in both outcomes) (moderate quality of evidence for both outcomes, downgraded one level for indirectness). The number of infants who required exchange transfusion was similar between the two groups (RR 1.60, 95% CI 0.60 to 4.27; RD 0.11, 95% CI -0.12 to 0.34; participants = 54). No infant in either group developed adverse effects including vomiting or abdominal distension.

AUTHORS' CONCLUSIONS

There is no evidence that IV fluid supplementation affects important clinical outcomes such as bilirubin encephalopathy, kernicterus, or cerebral palsy in healthy, term newborn infants with unconjugated hyperbilirubinaemia requiring phototherapy. In this review, no infant developed these bilirubin-associated clinical complications. Low- to moderate-quality evidence shows that there are differences in total serum bilirubin levels between fluid-supplemented and control groups at some time points but not at others, the clinical significance of which is uncertain. There is no evidence of a difference between the effectiveness of IV and oral fluid supplementations in reducing serum bilirubin. Similarly, no infant developed adverse events or complications from fluid supplementation such as vomiting or abdominal distension. This suggests a need for future research to focus on different population groups with possibly higher baseline risks of bilirubin-related neurological complications, such as preterm or low birthweight infants, infants with haemolytic hyperbilirubinaemia, as well as infants with dehydration for comparison of different fluid supplementation regimen.

ABM Clinical Protocol #10: Breastfeeding the Late Preterm (34-36 6/7 Weeks of Gestation) and Early Term Infants (37-38 6/7 Weeks of Gestation), Second Revision 2016

A central goal of the Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient.

Establishing successful breastfeeding in the newborn period

The first days after delivery of a newborn infant are critical for breastfeeding establishment. Successful initiation and continuation-especially of exclusive breastfeeding-have become public health priorities, but it is fraught with many individual- and systems-level barriers. In this article, we review how hospital newborn services can be constructed or restructured to support the breastfeeding mother-infant dyad so that they can achieve high levels of breastfeeding success. Important positive and negative factors from the prenatal period, and the preparation for hospital discharge are also discussed.

Transcutaneous bilirubin in exclusively breastfed healthy term newborns up to 12 days of life

OBJECTIVE

To determine the curve of transcutaneous bilirubin in breastfed term neonates up to 12 days of life.

METHODS

In a prospective cohort study, we performed a 12-day evaluation of 223 healthy, exclusively breastfed, appropriate-for-gestational-age neonates who roomed-in for at least 48 hours. Each newborn had forehead transcutaneous bilirubin and body weight measured at the end of 1, 2, 3, 4, 5, 6, 8, 10, and 12 days. Regression analysis was used with bilirubin as a third-degree polynomial function of time. The 25th, 50th, 75th, 90th, and 95th percentile curves were constructed by using the residual mean square for each day.

RESULTS

Patients were 46% white, 34% mixed race, and 20% black, the mean birth weight was 3260 g (range: 2560-4090 g), the mean gestational age was 39.4 weeks (range: 37.0-41.9 weeks), 51% were male, 74% were born by vaginal delivery, and 66% had been breastfed since delivery. The mean highest weight loss was 4.7% (range: 1%-12%) at the second or third day, and in most infants the weight returned to the birth weight at the fifth day. With 2007 total bilirubin measurements, bilirubin concentrations reached the 50th percentile level (5.6 mg/dL) at the third and fourth days and returned to the 24-hour level (4.8 mg/dL) at the sixth day. The 95th percentile bilirubin level was 8.2 mg/dL at 24 hours of life, reached 12.2 mg/dL on the fourth day, and declined to 8.5 mg/dL on the 12th day.

CONCLUSIONS

The transcutaneous bilirubin curve represents the natural history of bilirubinemia in exclusively breastfed healthy term newborns in the first 12 days of life.

Prevention of neurodevelopmental sequelae of jaundice in the newborn

Although its cause, jaundice in the newborn, is extremely common, the disabling neurological disorder kernicterus is very rare. Kernicterus may be prevented by selecting those infants who are at risk of extreme jaundice or who may be particularly vulnerable to bilirubin neurotoxicity. Because the tools for achieving that goal are inadequate, a secondary strategy is needed. This involves a plan for emergency treatment of severely jaundiced infants, in particular those who present with neurological symptoms. In this paper I review the strategies for preventing extreme jaundice, and for reversing neurotoxicity in those infants for whom the principal strategies fail. Briefly, the tools for prevention include measurement of bilirubin while the infant is staying in the maternity unit, plotting the value on an hour-specific chart, assessing other risk factors for jaundice, and educating the parents. Emergency treatment should include immediate, high-irradiance phototherapy, consideration of intravenous immune globulin, and preparation for an exchange transfusion.

ABM clinical protocol #10: breastfeeding the late preterm infant (34(0/7) to 36(6/7) weeks gestation) (first revision June 2011)

A central goal of The Academy of Breastfeeding Medicine is the development of clinical protocols for managing common medical problems that may impact breastfeeding success. These protocols serve only as guidelines for the care of breastfeeding mothers and infants and do not delineate an exclusive course of treatment or serve as standards of medical care. Variations in treatment may be appropriate according to the needs of an individual patient. These guidelines are not intended to be all-inclusive, but to provide a basic framework for physician education regarding breastfeeding.

Why we are still doing so many exchange blood transfusion for neonatal jaundice in Nigeria

BACKGROUND

Since exchange blood transfusion (EBT) is associated with serious complications, phototherapy has been made more powerful to reduce the need for EBT in the developed world. This study was undertaken to determine the indications for EBT in neonatal jaundice (NNJ) at our unit and what proportion of EBTs was possibly avoidable.

METHODS

All the babies who had EBT for hyperbilirubinemia over a three-year period were included. Age, sex, weight, place of delivery, blood group of baby and mother, other investigations, management, and the outcome of the babies were recorded.

RESULTS

Of the 1686 babies admitted to the neonatal unit, 90 (5.3%) had EBT. Fourteen (15.6%) were inborn while 76 (84.4%) were out-born babies. Fifty-six (62.2%) babies were admitted primarily for NNJ while 34 (37.8%) developed NNJ during admission. Thirty-six (40.0%) of the babies had phototherapy for more than 24 hours prior to EBT either because they were of very low birthweight or NNJ was detected very early and therapy was so commenced. Sixty-eight (75.6%) babies had single EBT while the remaining 22 (24.4%) had two sessions of EBT. Factors associated with severe NNJ in babies requiring EBT included low birthweight (<2500 g, 44.4%), ABO incompatibility (30.0%), glucose-6-phosphate dehydrogenase deficiency (34.4%) and septicemia (26.1%). Twenty-seven (30.0%) of the neonates developed features of kernicterus: 26 before admission while 1 during admission; all except one were delivered outside the hospital.

CONCLUSIONS

The EBT rate in our center was high. With more effective phototherapy, EBT could be avoided in most of the babies who initially had phototherapy for more than 24 hours before EBT and repeated EBT sessions. Health education of the population at risk, especially pregnant women, and early referral at the primary health care level will reduce the burden of severe NNJ.

Early recognition of neonatal hyperbilirubinemia and its emergent management

Hyperbilirubinemia and kernicterus are re-emerging as prominent clinical concerns and have been hypothesized to be secondary to increased breast-feeding rates, early hospital discharges and overall lack of concern for the potential impact of severe hyperbilirubinemia on healthy term newborns. Although the clinical symptoms can be non-specific and vague, they could be early, insidious and heralding signs of acute bilirubin encephalopathy (ABE) or acute stage kernicterus. Because it is highly prevalent, evaluation of a jaundiced neonate requires detailed questions about specific signs, review of birth and postnatal histories, evaluation of predischarge data, and possibly an emergency clinical evaluation of the neurological status of the infant. Medical urgency to evaluate, investigate and monitor such a newborn ensues from the possibility of rapid progression that might lead to permanent sequelae of bilirubin-induced neurologic dysfunction (BIND). Early recognition of the urgency and rapid transition to treatment seem to be the major barriers leading to delay in therapy. However, because there is a well-established and relatively safe treatment for neonatal jaundice, there should be zero tolerance for kernicterus, and BIND prevention has become a national priority in the USA. This paper reviews the clinical signs and epidemiology of ABE and BIND and presents a system-based strategy for preventing their occurrence, focusing particularly on the transition from recognition of clinical jaundice to actual treatment. A novel emergency-room-based protocol is presented as an example of how to expedite and facilitate rapid progression to treatment.

A controlled, randomized, double-blind trial of prophylaxis against jaundice among breastfed newborns

OBJECTIVES

Neonatal jaundice is a greater problem for infants fed breast milk, compared with formula. This study tested the hypotheses that feeding breastfed newborns beta-glucuronidase inhibitors during the first week after birth would increase fecal bilirubin excretion and would reduce jaundice without affecting breastfeeding deleteriously.

METHODS

Sixty-four breastfed newborns were randomized to 4 groups, ie, control or receiving 6 doses per day (5 mL per dose) of L-aspartic acid, enzymatically hydrolyzed casein (EHC), or whey/casein (W/C) for the first week. L-aspartic acid and EHC inhibit beta-glucuronidase. Transcutaneous bilirubin levels (primary outcome) were measured daily (Jaundice Meter [Minolta/Air Shields, Hatboro, PA] and Bilicheck [Respironics, Pittsburgh, PA]). All stools were collected, and fecal bile pigments, including bilirubin diglucuronide, bilirubin monoglucuronides, and bilirubin, were analyzed with high-performance liquid chromatography. Follow-up assessments included day 7 body weight, day 6/7 prebreastfeeding/postbreastfeeding weights, maternal ratings, and ages at formula introduction and breastfeeding cessation.

RESULTS

The groups were comparable at entry. Overall, the L-aspartic acid, EHC, and W/C groups had significantly lower transcutaneous bilirubin levels than did the control group (75.8%, 69.6%, and 69.2%, respectively, of the control mean, 8.53 mg/dL, at the bilirubin peak on day 4). The L-aspartic acid, EHC, and W/C groups had significantly lower transcutaneous bilirubin levels on days 3 to 7. Fecal bile pigment excretion was greatest in the L-aspartic acid group, significantly greater than control values. There were no significant differences in dosages, follow-up measurements, and maternal ratings.

CONCLUSIONS

Use of minimal aliquots of L-aspartic acid and EHC for beta-glucuronidase inhibition results in increased fecal bilirubin excretion and less jaundice, without disruption of the breastfeeding experience. Decreased jaundice in the W/C group, which lacked a beta-glucuronidase inhibitor, suggests a different mechanism.

Recent advances in the pharmacotherapy for hyperbilirubinaemia in the neonate

Jaundice is a common cause for diagnostic works-up and therapeutic intervention in neonates. This is motivated by the risk for severe neurological sequelae (kernicterus). The mainstays of treatment for the past decades have been exchange transfusion and phototherapy. Exchange transfusion is now becoming rare due to immune prophylaxis in Rhesus-negative women, and treatment of sensitised infants with intravenous immunoglobulin. Several different pharmacological approaches have been studied as far as the treatment of neonatal jaundice. Of these, the focus of attention in recent years has been on the haem oxygenase inhibitors (metal meso- and protoporphyrins). These are effective inhibitors of bilirubin production and have been shown to significantly reduce peak serum bilirubin levels in several clinical trials, both when used prophylactically and therapeutically. However, questions remain regarding long-term safety, as well as the advisability of whole-scale inhibition of bilirubin production. Nevertheless, in selected infants with a high risk of severe jaundice, the use of haem oxygenase inhibitors may be acceptable. Pharmacotherapy in jaundiced infants is fraught with risks, as many drugs may increase the entry of bilirubin into the brain and presumably, the risk for neurotoxicity. Both the displacement of bilirubin from its albumin binding and interference with the function of phosphoglycoprotein in the blood-brain barrier are documented mechanisms in this respect.

The effect of zinc salts on serum bilirubin levels in hyperbilirubinemic rats

OBJECTIVES

Intestinal metabolism of bilirubin is implicated in the pathogenesis of neonatal jaundice and Crigler-Najjar syndrome. In the present study the authors investigated the effect of oral administration of zinc salts on serum bilirubin levels in hyperbilirubinemic rats.

METHODS

Bilirubin-binding activities of zinc sulfate and water-insoluble zinc methacrylate were determined in vitro. Congenitally hyperbilirubinemic Gunn rats and artificially hyperbilirubinemic Wistar rats were used in in vivo studies. Animals were fed a normal diet for 1 week and then a treatment diet of either zinc sulfate or zinc methacrylate for additional 2 weeks. Serum and fecal bile pigments were determined at the end of each phase. Biliary bilirubin secretion rates were determined in hyperbilirubinemic Wistar rats fed zinc methacrylate.

RESULTS

Substantial bilirubin-binding activities of zinc salts were demonstrated in in vitro experiments. Treatment with oral zinc salts significantly decreased serum bilirubin levels in Gunn rats (166 +/- 53 versus 123 +/- 38 and 206 +/- 34 versus 131 +/- 31 micromol/L, P < 0.05 for zinc methacrylate and zinc sulfate, respectively). A similar effect of zinc methacrylate was also observed in hyperbilirubinemic Wistar rats (102 +/- 10 versus 14 +/- 4 micromol/L, P < 0.0001). In accord, biliary bilirubin secretion decreased significantly in these animals (45 +/- 11 versus 28 +/- 4 nmol/h 100g body weight, P < 0.02). In contrast to zinc sulfate, treatment with zinc methacrylate did not lead to the elevation of serum zinc levels.

CONCLUSIONS

Oral administration of zinc salts efficiently decreased serum bilirubin levels in hyperbilirubinemic rats, presumably as a result of inhibition of enterohepatic circulation of bilirubin. This approach might be useful in the treatment of severe unconjugated hyperbilirubinemias.

Breast-feeding, neonatal jaundice and kernicterus

Despite the many advantages of breast-feeding, there is ample documentation of the strong association between breast-feeding and an increase in the risk of neonatal hyperbilirubinaemia. Breast-fed infants have higher bilirubin levels than formula-fed infants. Suggested mechanisms for these findings include poor fluid and caloric intake, inhibition of hepatic excretion of bilirubin, and intestinal absorption of bilirubin (enterohepatic circulation). On rare occasions, breast-fed infants without evidence of haemolysis have developed extreme hyperbilirubinaemia and kernicterus. Because almost all of the cases of kernicterus reported in the last 15 years have occurred in fully or partially breast-fed newborns, it is important that these infants be followed closely. Appropriate support and advice must be provided to the lactating mother so that successful breast-feeding can be established and the risk of severe hyperbilirubinaemia reduced.

A novel inhibitor of beta-glucuronidase: L-aspartic acid

Infants who consume casein hydrolysate formula have been shown to have lower neonatal jaundice levels than infants who consume routine formula or breast milk. Because casein hydrolysate has been shown to contain a beta-glucuronidase inhibitor, one possible mechanism to explain this finding is blockage of the enterohepatic circulation of bilirubin by a component of the formula. The aim of this research was to identify the source of the beta-glucuronidase inhibition in hydrolyzed casein. A beta-glucuronidase inhibition assay and measurements of physical and kinetic parameters were used to analyze the components of hydrolyzed casein and infant formulas. Kinetic studies used purified beta-glucuronidase. The L-aspartic acid in hydrolyzed casein accounts for the majority of the beta-glucuronidase inhibition present. Kinetic studies indicate a competitive inhibition mechanism. L-aspartic acid is a newly identified competitive inhibitor of beta-glucuronidase.

Rehospitalisation for neonatal jaundice: risk factors and outcomes

This case-control study sought to determine whether rehospitalisation for jaundice in newborns is associated with the length of hospital stay after birth and to identify risk factors for and outcomes of rehospitalisation for jaundice. It was carried out among women who delivered a normal, term infant vaginally at any of 10 medical centres from 1992 to 1994. Cases were infants rehospitalised with jaundice within 14 days of birth. Controls were randomly selected from normal, term infants delivered vaginally but not rehospitalised within 90 days of birth. Maternal medical records for pregnancy, labour and delivery care, records for all the birth hospitalisations, and rehospitalisations for the cases were abstracted. The length of birth hospitalisation did not differ between case and control infants, whether length was measured as a categorical variable or as a continuous measure (median = 22.8 h for cases and 23.3 h for controls, P = 0.931). Rehospitalisation for jaundice was associated with race/ethnicity, primiparity, preterm birth, breast feeding and suspicion of jaundice during the birth hospitalisation. None of the rehospitalised infants died, were diagnosed with kernicterus or required resuscitation. Attention to risks associated with jaundice rehospitalisation might reduce this undesirable, but not commonly severe, outcome.

Neonatal jaundice, animal-induced injuries, and immunizations

The authors describe current investigation and most recent developments in three areas of pediatrics commonly faced by the office practitioner. The impetus of earlier newborn discharge places increased emphasis on pediatricians to accurately predict clinically significant jaundice. A better understanding of the pathophysiology of breastfeeding and breast milk jaundice, and the realization that Gilbert's syndrome may play a greater role in neonatal jaundice, only help confirm that the story of neonatal jaundice is still unfolding. Animal (particularly canine) bite injuries continue to be the most common animal-induced injuries, and a thorough review of appropriate antibiotic treatment and rabies prophylaxis guidelines are essential for the pediatric practitioner. During the past year, several major changes involving the use of rotavirus, pneumococcal, polio, meningococcal, and hepatitis A vaccines have taken place, which will have marked impact not only on pediatric office practice, but also on society as a whole.

Noninvasive measurement of total serum bilirubin in a multiracial predischarge newborn population to assess the risk of severe hyperbilirubinemia

BACKGROUND

Jaundice in near-term and term newborns is a frequent diagnosis that may prompt hospital readmission in the first postnatal week. Hyperbilirubinemia, when excessive, can lead to potentially irreversible bilirubin-induced neurotoxicity. Predischarge risk assessment (at 24-72 hours of age) for subsequent excessive hyperbilirubinemia is feasible by a laboratory-based assay of total serum bilirubin (TSB). Hypothesis. Noninvasive, transcutaneous, point-of-care measurement of transcutaneous bilirubin (TcB) predischarge by multiwavelength spectral analysis, using a portable BiliCheck device (SpectRx Inc, Norcross, GA), is clinically equivalent to measurement of TSB in a diverse, multiracial term and near-term newborn population and predictive of subsequent hyperbilirubinemia.

METHODOLOGY

We evaluated a hand-held device that uses multiwavelength spectral reflectance analysis to measure TcB (BiliCheck). The study population (490 term and near-term newborns) was racially diverse (59.1% white, 29.5% black, 3.46% Hispanic, 4.48% Asian, and 3.46% other) and was evaluated at 2 separate institutions using multiple (11) devices. The postnatal age ranged from 12 to 98 hours and the ranges of birth weights and gestational ages were 2000 to 5665 g and 35 to 42 weeks, respectively. All transcutaneous evaluations were performed contemporaneously and paired with a heelstick TSB measurement. All TSB assays were performed by high performance liquid chromatography, as well as by diazo dichlorophenyldiazonium tetrafluoroborate techniques.

RESULTS

TSB values ranged from .2 to 18.2 mg/dL (mean +/- standard deviation: 7.65 +/- 3.35 mg/dL). The overall correlation of TSB (by high performance liquid chromatography technique) to TcB (by BiliCheck devices) was linear and statistically significant (r =.91; r(2) =.83; TcB =.84; TSB = +.75; standard error of regression line = 1.38; P <.001; n = 490 infants; 1788 samples). Similar regression statistics were evident in subset populations categorized by race (white: r =.91 [n = 289 infants]; black: r =.91 [n = 145 infants]) as well as by gestation (term: r =. 91 [n = 1625 samples]; near-term: r =.89 [n = 163 samples]). Intradevice precision was determined to be.59 mg/dL (2-3 measurements per infant with 1 device; n = 210 infants; 510 samples in a separate subset). Interdevice evaluation of 11 devices determined the precision to be.68 mg/dL (2-4 devices used for measurements per patient). In 23 of 419 of the study population infants who were in the 24- to 72-hour age range, the predischarge TSB values designated them to be at high risk for subsequent excessive hyperbilirubinemia (above the 95th percentile track on the hour-specific bilirubin nomogram). For these infants, the paired BiliCheck TcB values were all above the 75th percentile track (negative predictive value = 100%; positive predictive value = 32. 86%; sensitivity = 100%; specificity = 88.1%; likelihood ratio = 8. 43).

CONCLUSIONS

Our data demonstrate the accuracy and reproducibility of the predischarge BiliCheck measurements in term and near-term newborn infants of diverse races and ethnicities. Infants with predischarge BiliCheck values above the 75th percentile of hour-specific TSB values on the bilirubin nomogram may be considered to be at high risk for subsequent excessive hyperbilirubinemia. Further studies are needed to assess the efficacy of this technique in preterm infants, those undergoing phototherapy, and those with TSB values of >/=15 mg/dL (>/=256 micromol/L).

Neonatal jaundice, animal-based injuries, and immunizations

The authors describe current investigation in three areas of pediatrics commonly faced by the office practitioner. Despite the fact that changes in medical practice and in patient demographics have resulted in the reemergence of severe hyperbilirubinemia and bilirubin encephalopathy, clinical assessment and evaluation of discharge bilirubin levels may help predict those infants at greatest risk. Progress in the use of inhibitors of bilirubin production may eventually decrease the need for phototherapy. Although dog-associated injuries continue to affect children disproportionately, additional attention to anticipatory guidance may prove beneficial. The practice of routine immunization has reshaped our view of pediatric illness. The development of pneumococcal, meningococcal, and rotaviral vaccines will alter significantly the prevalence of common pediatric infectious disease. However, with the advent of additional vaccines, attention to pain control will take on increasing urgency.