Normal serum bilirubin levels in the newborn and the effect of breast-feeding

We measured the serum bilirubin concentrations in 2,416 consecutive infants admitted to our well-baby nursery. The maximum 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 maximum serum bilirubin levels less than or equal to 12.9 mg/dL. In 66 infants (44.9%), we identified an apparent cause for the jaundice, but in 81 (55%), no cause was found. Of infants for whom no cause for hyperbilirubinemia was found, 82.7% were breast-fed v 46.9% in the control group (P less than .0001). Breast-feeding was significantly associated with hyperbilirubinemia, even in the first three days of life. The 95th percentile for bottle-fed infants is a serum bilirubin level of 11.4 mg/dL v 14.5 mg/dL for the breast-fed population, and the 97th percentiles are 12.4 and 14.8 mg/dL, respectively. Of the formula-fed infants, 2.24% had serum bilirubin levels greater than 12.9 mg/dL v 8.97% of breast-fed infants (P less than .000001). When compared with previous large studies, the incidence of "readily visible" jaundice (serum bilirubin level greater than 8 mg/dL) appears to be increasing. The dramatic increase in breast-feeding in the United States in the last 25 years may explain this observation. There is a strong association between breast-feeding and jaundice in the healthy newborn infant. Investigations for the cause of hyperbilirubinemia in healthy breast-fed infants may not be indicated unless the serum bilirubin level exceeds approximately 15 mg/dL, whereas in the bottle-fed infant, such investigations may be indicated if the serum bilirubin exceeds approximately 12 mg/dL.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hyperbilirubinemia in preterm infants and neurodevelopmental outcome at 2 years of age: results of a national collaborative survey

As part of a prospective national survey of preterm and small for gestational age infants in the Netherlands, the relationship between maximal serum total bilirubin concentration in the neonatal period and neurodevelopmental outcome at the corrected age of 2 years was studied. Initially, 1,338 infants with a gestational age of less than 32 completed weeks and/or a birth weight of less than 1,500 g were enrolled in the study; 146 were subsequently excluded because of congenital malformations and 361 died during the study period. At the corrected age of 2 years, 831 children were available for follow-up. Children with minor and major handicaps had significantly greater maximal serum total bilirubin concentrations than children with a normal neurodevelopmental outcome (P = .02). A consistent increase in prevalence of handicaps was found for each 50-mumol/L (2.9 mg/dL) increase of maximal serum total bilirubin concentration. The handicaps consisted mainly of cerebral palsy. Logistic regression analysis involving seven suspected confounding factors (gestational age, birth weight, seizures, intracranial hemorrhage, respiratory distress syndrome, ventriculomegaly, and bronchopulmonary dysplasia) revealed that the odds ratio was 1.3. This indicates that, on a multiplicative scale, the risk of a handicap increased by 30% for each 50-mumol/L (2.9 mg/dL) increase of maximal serum total bilirubin concentration (P = .02). Further analysis treated bilirubin as a categorized exposure. A striking systematic increase was found, suggesting a causal relationship between maximal serum total bilirubin concentration and neurodevelopmental outcome.     

Home health nurse clinical assessment of neonatal jaundice: comparison of 3 methods

OBJECTIVE: To compare 3 methods of clinical assessment of jaundice in newborns by home health nurses. DESIGN: Prospective clinical trial. SETTING: Homes of newborns living within 10 miles of a 340-bed community hospital where they were delivered. PARTICIPANTS: Home health nurses and newborn patients (< or =2 weeks old). INTERVENTIONS: The nurses examined the newborns and documented whether they detected jaundice. In newborns thought to have jaundice, the nurses estimated bilirubin levels, documented the extent of caudal progression of the jaundice, and determined the Ingram (Cascade Health Care Products, Salem, Ore) icterometer readings from the newborns' noses. Total serum bilirubin tests were obtained from all newborns studied. OUTCOME MEASURES: Nurse assessment of the presence of jaundice and its caudal progression, nurse estimates of bilirubin levels, icterometer readings, and bilirubin levels. RESULTS: The nurses determined that 82 (50%) of the 164 newborns had jaundice. Their estimates of bilirubin levels were most highly correlated with serum bilirubin levels (Pearson correlation, 0.61). All 3 newborns with bilirubin levels greater than or equal to 291 micromol/L (> or =17 mg/dL) were recognized by the nurses as having jaundice. These newborns had icterometer readings greater than or equal to 3.5 and had estimated bilirubin levels of greater than or equal to 274 micromol/L (> or =16 mg/dL). CONCLUSIONS: The method of evaluation that each nurse was accustomed to using was the most accurate in determining the severity of newborn jaundice. These results suggest that postpartum home health nurses can effectively evaluate newborns for the presence and severity of jaundice.     

Neonatal hyperbilirubinemia associated with glucose-6-phosphate dehydrogenase deficiency in Sephardic-Jewish neonates: incidence, severity, and the effect of phototherapy.

Glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is frequently associated with neonatal hyperbilirubinemia, and sometimes kernicterus, often in the absence of any identifiable trigger or hematological evidence of hemolysis. The aim of this study was to compare the incidence and severity of, and the effect of phototherapy on, jaundice in G 6-PD-deficient vs G-6-PD-normal neonates in the Sephardic-Jewish community. Healthy term newborns, born to mothers of families stemming from geographic areas known to be "at risk" for G-6-PD deficiency, were screened for the condition and surveyed for hyperbilirubinemia. Seventy-five G-6-PD-deficient neonates formed the study group, while 266 neonates with normal levels of the enzyme formed the control group. Neonates with any other identifiable cause for jaundice were excluded. Phototherapy was commenced when the serum bilirubin levels reached 16 mg/dL (274 mumol/L) or more, and it was discontinued at 12 mg/dL (205 mumol/L) or less. Hyperbilirubinemia developed in 27 (36%) of the deficient neonates (serum total bilirubin greater than 13.9 mg/dL [238 mumol/L]), compared with 50 (18.8%) of control neonates (P = .002), while 20 (26.7%) of the study group required phototherapy, compared with 31 (11.7%) of control neonates (P = .002). Two neonates in the study group required exchange transfusion (serum bilirubin greater than 20 mg/dL [342 mumol/L]), vs 0 in the control group (not significant).(ABSTRACT TRUNCATED AT 250 WORDS)     

Auditory nerve-brainstem evoked responses in hyperbilirubinemic neonates

On the basis of the known predilection of the auditory brainstem pathway for bilirubin toxicity, we have examined auditory brainstem responses of neonates during the period of hyperbilirubinemia. The auditory brainstem responses of 24 infants with serum bilirubin values between 15 to 25 mg/dL were compared with the responses of 19 infants without hyperbilirubinemia, who had similar gestational and postnatal ages. Wave IV-V complex was absent in at least one recording of 10/24 jaundiced infants, whereas wave complex IV-V was consistently present in all of the 19 infants without hyperbilirubinemia (P less than .001). Jaundiced infants also had prolonged brainstem transmission time (P less than .01) which reflected increased latency at both lower and upper brainstem levels. The above changes were rapidly reversed in the majority of instances. Neonatal jaundice was associated with significant transient aberrations of auditory brainstem responses, suggestive of a transient brainstem encephalopathy. This evidence of bilirubin entry to the brain at conventionally acceptable serum concentrations raises questions about current concepts of the mechanism of transfer of bilirubin across the blood-brain barrier.     

Extreme hyperbilirubinemia in newborn infants

This study was undertaken to determine the frequency and investigate the etiology of extreme hyperbilirubinemia (total serum bilirubin [TSB]>or=25 mg/dL [428 micromol/L]) in newborns admitted to a neonatal intensive care unit in southern Turkey. The charts of 93 term and near-term infants admitted with TSB levels of 25 mg/dL (428 micromol/L) or greater in the first 30 days after birth were retrospectively reviewed. During the 4.5-year study period, 774 infants were admitted to our unit with neonatal jaundice. Ninety-three (12%) of these infants had TSB levels of 25 mg/dL (428 micromol/L) or greater. The mean TSB level in the 93 cases was 30.1+/-5.7 mg/dL (514.7+/-97.5 micromol/L), and the peak levels ranged from 25.0 to 57.4 mg/dL (428-981.5 micromol/L). Thirty-three (35.5%) of the 93 babies had TSB levels of 30 mg/dL (513 micromol/L) or greater. Eighty-nine of 93 infants were being exclusively breast-fed. Nineteen babies were isoimmunized, 7 were bacteremic, 2 of the 39 babies tested for glucose-6-phosphate dehydrogenase had this enzyme deficiency, and 1 of the 71 infants tested for thyroid function had hypothyroidism. No cause for extreme hyperbilirubinemia was found in 61 (65.6%) cases.     

Epidemiology of neonatal jaundice in the Jerusalem population

Of 10,122 singleton babies born from January 1, 1984 to March 31, 1988, we compared 1,154 term infants with high serum bilirubin levels (greater than 12.9 mg/dl) to 1,154 infants with low serum bilirubin levels (less than or equal to 12.9 mg/dl) randomly selected from the remaining 8,968 subjects. We found that a high bilirubin level was significantly associated with male sex; maternal diabetes (chronic and gestational); pregnancy-induced hypertension; previous sibling with neonatal jaundice; delivery by cesarean section, vacuum, or forceps; epidural anesthesia; mother with blood type O; first delivery; cephalohematoma; short gestation; lower birth weight; and lower birth order (p less than 0.01); and older maternal age, low percentile for birth weight, and the percentage of weight loss during hospitalization (p less than 0.05). Variables with significantly different frequencies in control and study groups were used in a multivariate analysis, thus further refining the data by the use of logistic regression. Teenage mothers (less than or equal to 19 years old) had the lowest risk, whereas older mothers (greater than 35 years old) had the highest risk of all age groups for having an infant with neonatal jaundice. First delivery and previous sibling with neonatal jaundice were also risk factors. Male sex, short gestation, and delivery by vacuum extraction were other notable risk factors. Our results suggest that, even among industrialized Western societies, risk factors may interact differently to produce higher neonatal serum bilirubin levels. The importance of a risk factor may also be dependent upon its relative prevalence in a parturient population.     

Outcomes of extremely premature infants related to their peak serum bilirubin concentrations and exposure to phototherapy

OBJECTIVES: To analyze, in extremely low birth weight infants, associations between peak bilirubin concentration and evidence of brain damage, and between peak bilirubin concentration and blindness attributable to retinopathy of prematurity. METHODS: Retrospective study of 128 infants of /=9.4 mg/dL (odds ratio [OR] confidence interval [CI] 4.48 [1.15-17.43])), low gestational age (OR [CI] per week 1.95 [1.05-3.63]), and longer duration of phototherapy (OR [CI] per 10 hours 1.17 [1.02-1.33]). The association of neurodevelopmental impairment with grades 3 and 4 intraventricular hemorrhage was statistically significant (OR 5.39 [1.83-15.84]), but with high-peak serum bilirubin concentration >/=11.7 mg/dL (>/=200 micromol/L), was not significant (OR 2.89 [0. 87-9.53]). CONCLUSIONS: In these infants, prolonged phototherapy and low-peak serum bilirubin concentrations were associated with severe visual loss attributable to retinopathy of prematurity. The findings should be interpreted with caution until the evidence is reinforced in other patient populations.     

Capillary and venous bilirubin values. Are they really different?

We measured total serum bilirubin values in paired capillary and venous samples from 79 untreated jaundiced newborn infants (group 1) and in 29 infants who were receiving phototherapy (group 2). While bilirubin values from the two sites correlated significantly for both groups, capillary samples underestimated venous bilirubin values when the latter exceeded 170 mumol/L (10 mg/dL) (mean and 95% confidence limits: group 1, -15.1 mumol/L [-0.9 mg/dL] and -24.7 to -5.5 mumol/L [-1 to -0.3 mg/dL]; group 2, -10.3 mumol/L [-0.6 mg/dL] and -17.1 to -3.4 mumol/L [-1 to -0.2 mg/dL]). Furthermore, capillary samples underestimated venous bilirubin levels by more than 17 mumol/L (1 mg/dL) in eight of 16 group 1 patients and five of 18 group 2 patients when venous bilirubin values exceeded 170 mumol/L (10 mg/dL). Lower capillary values at higher bilirubin levels might be due to the influence of environmental light. As clinical treatment decisions may be made on the basis of differences in serum bilirubin level of about 17 mumol/L (1 mg/dL) and as capillary samples may underestimate venous bilirubin levels by a similar amount, it may be prudent to measure venous rather than capillary bilirubin levels when the total serum bilirubin level exceeds 170 mumol/L (10 mg/dL).     

An evidence-based review of important issues concerning neonatal hyperbilirubinemia

This article is adapted from a published evidence report concerning neonatal hyperbilirubinemia with an added section on the risk of blood exchange transfusion (BET). Based on a summary of multiple case reports that spanned more than 30 years, we conclude that kernicterus, although infrequent, has at least 10% mortality and at least 70% long-term morbidity. It is evident that the preponderance of kernicterus cases occurred in infants with a bilirubin level higher than 20 mg/dL. Given the diversity of conclusions on the relationship between peak bilirubin levels and behavioral and neurodevelopmental outcomes, it is apparent that the use of a single total serum bilirubin level to predict long-term outcomes is inadequate and will lead to conflicting results. Evidence for efficacy of treatments for neonatal hyperbilirubinemia was limited. Overall, the 4 qualifying studies showed that phototherapy had an absolute risk-reduction rate of 10% to 17% for prevention of serum bilirubin levels higher than 20 mg/dL in healthy infants with jaundice. There is no evidence to suggest that phototherapy for neonatal hyperbilirubinemia has any long-term adverse neurodevelopmental effects. Transcutaneous measurements of bilirubin have a linear correlation to total serum bilirubin and may be useful as screening devices to detect clinically significant jaundice and decrease the need for serum bilirubin determinations. Based on our review of the risks associated with BETs from 15 studies consisting mainly of infants born before 1970, we conclude that the mortality within 6 hours of BET ranged from 3 per 1000 to 4 per 1000 exchanged infants who were term and without serious hemolytic diseases. Regardless of the definitions and rates of BET-associated morbidity and the various pre-exchange clinical states of the exchanged infants, in many cases the morbidity was minor (eg, postexchange anemia). Based on the results from the most recent study to report BET morbidity, the overall risk of permanent sequelae in 25 sick infants who survived BET was from 5% to 10%.     

Neonatal jaundice in full-term infants. Role of breast-feeding and other causes

Serum bilirubin determinations were performed on 264 term infants who were consecutively delivered via the vaginal route. Forty-one infants (15.5%) had serum bilirubin concentrations greater than 12 mg/dL. No cause for this was found, initially, in 23 (56%) of these infants. On the third hospital day, the mean (+/- SD) serum bilirubin level was 6.9 +/- 3.6 mg/dL in breast-fed infants and 6.5 +/- 3.2 mg/dL in bottle-fed infants. Of the 23 infants without obvious cause for hyperbilirubinemia, eight (four bottle-fed and four breast-fed infants) had serum bilirubin concentrations greater than 12 mg/dL on the third hospital day, whereas in 15 (14 breast-fed infants and one bottle-fed infant), the elevated serum bilirubin level occurred on day 4 or 5. Breast-feeding does not seem to affect the total serum bilirubin level in the first three days of life but may be associated with an increased incidence of hyperbilirubinemia subsequently. In a normal full-term population, routine investigations do not disclose a cause for hyperbilirubinemia in about half of the patients.     

Jaundice noted in the first 24 hours after birth in a managed care organization

OBJECTIVE: To investigate the significance of jaundice noted in the first 24 hours after birth in a community setting. DESIGN: Supplementary analyses of a nested case-control study. SETTING: Northern California Kaiser Permanente Medical Care Program. PATIENTS: Six hundred thirty-one randomly selected newborns (controls) and 140 cases with total serum bilirubin levels of 25 mg/dL (428 micro mol/L) or higher from a cohort of 105 384 newborns of at least 2000 g birth weight and at least 36 weeks' gestational age, born between January 1, 1995, and December 31, 1998. MAIN OUTCOME MEASURES: Notations of jaundice in the medical record, timing and results of bilirubin testing, use of phototherapy, and development of bilirubin levels of 25 mg/dL or higher. RESULTS: Among the controls, the cumulative probability of a notation of jaundice (corrected for early hospital discharge using survival analysis) was 2.8% within 18 hours and 6.7% within 24 hours. In these newborns, cumulative proportions that had bilirubin levels measured were 38% within 12 hours and 43% within 24 hours of when jaundice was first noted. About 40% of bilirubin levels measured within 24 hours were above the estimated 95th percentile for age. Compared with newborns not noted to be jaundiced on the first day, newborns noted to be jaundiced within 24 hours were more likely to receive phototherapy (18.9% vs 1.7%; relative risk, 10.1; 95% confidence interval, 4.2-24.4) and to develop a bilirubin level of 25 mg/dL or higher (odds ratio, 2.9; 95% confidence interval, 1.6-5.2), but the absolute risk increase for total serum bilirubin levels of 25 mg/dL or higher was 0.2%. CONCLUSION: Jaundice noted in the medical record in the first 24 hours after birth was uncommon and often clinically significant in this setting, but other factors also need to be considered in determining its importance.     

Skin bilirubin measurement during phototherapy in preterm and term newborn infants

Background

The few existing studies evaluating the reliability of transcutaneous bilirubin monitoring during phototherapy gave controversial results.

Aims

To evaluate the accuracy of transcutaneous bilirubin measurement in a large population of newborn infants, during phototherapy.

Study design and methods

Total serum bilirubin and transcutaneous bilirubin on patched and unpatched skin areas were simultaneously measured in newborn infants undergoing phototherapy. Transcutaneous measurements were performed with a multiwavelength transcutaneous bilirubinometer (Respironics BiliCheck™). The Passing-Bablok regression and the Bland-Altman plot were used to estimate the relationship between serum and transcutaneous bilirubin.

Results

We studied 364 newborn infants with a mean (SD) gestational age of 34.6 (3) weeks and a mean birth weight of 2371 (805) grams. Total serum bilirubin, patched transcutaneous bilirubin and unpatched transcutaneous bilirubin were similar before phototherapy. After 52 (33) hours of phototherapy, the difference between serum bilirubin and patched transcutaneous bilirubin was 0.2 (3.1) mg/dL (not significant) while the difference between serum bilirubin and unpatched transcutaneous bilirubin was 3.2 (3.0) mg/dL (p < 0.001). Statistical analysis showed a good agreement between serum bilirubin and patched transcutaneous bilirubin, while unpatched transcutaneous bilirubin underestimates serum levels. The difference between patched and unpatched values was significantly lower in preterm than in term infants (2.8 mg/dL vs. 3.6 mg/dL; p < 0.001).

Conclusion

BiliCheck can be safely used for the evaluation of bilirubin levels in newborn infants under phototherapy. Its reliability on patched skin of the forehead is high enough to consistently reduce blood draws and to ascertain when to discontinue phototherapy. Because of the individual variance, any clinical decision has to be taken on the basis of the transcutaneous bilirubin trend more than on a single value.     

Serum bile acids and their conjugates in breast-fed infants with prolonged jaundice

Serum bile acids and their conjugates were analysed in 20 breast-fed infants with prolonged jaundice. The mean total bile acid levels in serum were increased in the breast-fed infants with jaundice, as compared with those in either breastor bottle-fed infants without jaundice. However, there were no significant differences between the groups. All the breast-fed infants examined, regardless of association with jaundice, had a bile acid pattern dominated by taurine conjugates (the ratio of glycine- to taurine-conjugated bile acid, G/T ratio, less than 1.00). In contrast, the bottle-fed infants without jaundice had a pattern dominated by glycine conjugates (G/T ratio, more than 1.00). Among the breast-fed infants with jaundice, the mean G/T ratio in those who had serum bilirubin levels over 10 mg/100 ml was significantly lower than that in those who had serum bilirubin levels of less than 10 mg/100 ml. The altered bile acid metabolism might be associated with the pathology of breast milk jaundice.Abbreviation LP-X lipoprotein-X     

Acute management of extreme neonatal jaundice–––the potential benefits of intensified phototherapy and interruption of enterohepatic bilirubin circulation

Abstract Increasing numbers of neonates are being admitted to hospital because of extreme jaundice. Phototherapy should be very effective in such infants, because the efficacy of phototherapy is proportional to the concentration of bilirubin in the skin. Here, I report on four infants who were admitted for indirect serum bilirubin levels of >500 µmol/1 (>>30mg/dl). In one of them, unrecognized Rhesus immunization was the main cause of hyperbilirubinemia, while in the other three increased enterohepatic circulation of bilirubin was thought to be an important contributory factor. In all four infants phototherapy (11–14 µW/cm²/nm) with whole body exposure plus ad lib feeding with milk were initiated immediately upon admission to the nursery. After 2h serum bilirubin values were reduced by 170–185 µmol/1 (10-11mg/dl) in the first three infants, while in the fourth infant a reduction of 195 µmol/1 (11.3mg/dl) was seen in the 5h interval between the first and second bilirubin measurement. This experience suggests that in some infants with extreme jaundice, intensified phototherapy plus feeding with milk may be very effective in reducing serum bilirubin levels. Even if an exchange transfusion is performed, using this strategy in the waiting period may be beneficial, as both the rapid reduction in serum bilirubin levels as well as the conversion of significant amounts of bilirubin into water-soluble isomers may reduce the risk of neurotoxicity.     

Auditory nerve and brainstem responses in newborn infants with hyperbilirubinemia

To assess early bilirubin toxicity, a study was made of auditory brainstem responses in relation to total bilirubin levels as well as unbound bilirubin levels in 56 hyperbilirubinemic infants (total bilirubin greater than or equal to 15.0 mg/dL) and 24 infants who did not have jaundice. The latencies of wave I at 85 dB HL (hearing level) in hyperbilirubinemic infants were significantly greater than those in the control group. The latencies of wave I and V in hyperbilirubinemic infants with unbound bilirubin levels greater than or equal to 1.0 microgram/dL (group C) were greater than those in the control group and in the hyperbilirubinemic infants with unbound bilirubin levels less than 0.5 microgram/dL (group A) and with unbound bilirubin levels less than 1.0 microgram/dL (group B). There were no significant differences of the wave I-V interpeak latency between the control infants and the hyperbilirubinemic infants. Thirty of the 80 infants showed prolonged peak latencies (greater than the mean +/- 2 SD for the control infants) of wave I and/or V in one or both ears. The incidences of the prolonged peak latencies in group B (42%) and group C (89%) were significantly greater than that in the control group (12%). The serial determinations of auditory brainstem responses in infants treated with exchange transfusions revealed that the prolonged peak latencies before exchange transfusion improved at 48 and 96 hours after the procedure for wave I, and at 24, 48, and 96 hours after the procedure for wave V. The interpeak latency of wave I-V did not change with exchange transfusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

The role of haemolysis in neonatal hyperbilirubinaemia as reflected in carboxyhaemoglobin levels.

Carboxyhaemoglobin levels were measured in 250 consecutive, normal, term newborns and in a group of 75 severely jaundiced infants in an effort to assess the role of haemolysis in non-specific neonatal hyperbilirubinaemia--"Physiologic jaundice"-as well as in severe jaundice of various etiologies. In normal newborns a significant correlation (r=0.3293, p less than 0.001) was found between third-day carboxyhaemoglobin and serum bilirubin levels. Significant correlations were also found between the cord and third day values for carboxyhaemoglobin (infants of non-smoking mothers) for reticulocyte count, and for serum bilirubin. Third day haemoglobin showed no correlation with any of the other parameters including cord haemoglobin. Of the infants with third day carboxyhaemoglobin up to 0.75%, 1.7% had third day serum bilirubin values above 16.0 mg/100 ml. The corresponding percentage for the infants with carboxyhaemoglobin above 0.75% was 6.1%. It is concluded that increased rates of haemolysis due to as yet unspecified caused play an important role in the non-specific hyperbilirubinaemia of normal term newborns. As expected, high levels of carboxyhaemoglobin were found in infants with severe jaundice due to Rhesus and ABO haemolytic disease and glucose-6-phosphate dehydrogenase deficiency but also in jaundiced prematures and in Greek infants with severe jaundice of unknown cause.     

Neonatal liver disease

Establishing a rapid and accurate diagnosis of the cause of neonatal liver disease is an urgent matter. The initial detection of this condition relies on the sensitivity of the primary care provider or pediatrician to the signs and symptoms of jaundice and abnormal stool and urine color. It is critical to evaluate jaundice in any infant older than 2 weeks with measurement of fractionated bilirubin, and further assessment is necessary if the direct value is above 1.0 mg/dL in the setting of a total bilirubin of less than 5.0 mg/dL or a direct bilirubin of more than 20% of total if the total is more than 5.0 mg/dL. A diagnostic algorithm for the evaluation of infants who meet these criteria can guide physicians in selecting appropriate and timely diagnostic testing and referral to pediatric gastroenterology for these patients, whose outcome will rely on rapid diagnosis.     

Excessively high bilirubin and exchange transfusion in very low birth weight infants

Aim: To evaluate the performance of exchange transfusion in very low birth weight (VLBW) infants with excessively high serum bilirubin levels. Methods: A population‐based observational study using data collected by the Israel National VLBW Infant Database. The study sample comprised 13 499 infants. Two definitions of excessively high‐peak bilirubin levels that might be considered as threshold levels for performance of exchange transfusion were used. First, a bilirubin level of ≥15 mg/dL for all infants (PSB‐15), and second, incremental bilirubin levels ranging from 12 to 17 mg/dL according to gestational age (PSB‐GA). Results: Four hundreds sixty‐eight (3.5%) and 1035 infants (7.7%) infants in the PSB‐15 and in the PSB‐GA groups respectively had peak serum bilirubin levels above thresholds for exchange transfusion. Exchange transfusions were performed in 66 (14.1%) of these infants in the PSB‐15 group and 91 (8.8%) in the PSB‐GA group. Using logistic regression analysis, peak serum bilirubin was found as an independent factor for performing exchange transfusion. Conclusion: Exchange transfusion was performed in only 9–14% of VLBW infants with excessively high bilirubin levels. We speculate that this may be a result of an absence of definitive guidelines or the possible belief that the risks of exchange transfusion outweigh the potential risk of bilirubin‐induced neurological injuries.     

THE ROLE OF HAEMOLYSIS IN NEONATAL HYPERBILIRUBINAEMIA AS REFLECTED IN CARBOXYHAEMOGLOBIN LEVELS

Abstract. Carboxyhaemoglobin levels were measured in 250 consecutive, normal, term newborns and in a group of 75 severely jaundiced infants in an effort to assess the role of haemolysis in non-specific neonatal hyperbilirubinaemia—"Physiologic jaundice"—as well as in severe jaundice of various etiologies. In normal newborns a significant correlation ( r =0.3293, p <0.001) was found between third-day carboxyhaemoglobin and serum bilirubin levels. Significant correlations were also found between the cord and third day values for carboxyhaemoglobin (infants of non-smoking mothers) for reticulocyte count, and for serum bilirubin. Third day haemoglobin showed no correlation with any of the other parameters including cord haemoglobin. Of the infants with third day carboxyhaemoglobin up to 0.75%, 1.7% had third day serum bilirubin values above 16.0 mg/100 ml. The corresponding percentage for the infants with carboxyhaemoglobin above 0.75% was 6.1%. It is concluded that increased rates of haemolysis due to as yet unspecified causes play an important role in the non-specific hyperbilirubinaemia of normal term newborns. As expected, high levels of carboxyhaemoglobin were found in infants with severe jaundice due to Rhesus and ABO haemolytic disease and glucose-6-phosphate dehydrogenase deficiency but also in jaundiced prematures and in Greek infants with severe jaundice of unknown cause.