Neonatal hyperbilirubinemia management: Clinical assessment of bilirubin production

Erythrokinetic mechanism(s) causing the "late anemia" of hemolytic disease of the fetus and newborn

A transfusion-requiring "late anemia" can complicate the management of neonates convalescing from hemolytic disease of the fetus and newborn (HDFN). This anemia can occur in any neonate after HDFN but is particularly prominent in those who received intrauterine transfusions and/or double-volume exchange transfusions. Various reports describe this condition as occurring based on ongoing hemolysis, either due to passive transfer of alloantibody through breast milk or persistence of antibody not removed by exchange transfusion. However, other reports describe this condition as the result of inadequate erythrocyte production. Both hypotheses might have merit, because perhaps; (1) some cases are primarily due to continued hemolysis, (2) others are primarily hypoproductive, and (3) yet others result from a mixture of these two mechanisms. We propose prospective collaborative studies that will resolve this issue by serially quantifying end-tidal carbon monoxide. Doing this will better inform the assessment and treatment of neonates recovering from HDFN.

End-tidal carbon monoxide concentrations measured within 48 hours of birth predict hemolytic hyperbilirubinemia

OBJECTIVES

To determine, among neonates at-risk for hyperbilirubinemia, whether measuring end-tidal carbon monoxide concentration (ETCOc) twice before 48 hours could identify those who would develop hyperbilirubinemia and differentiate hemolytic vs. non-hemolytic causes.

METHODS

Prospective study on neonates meeting criteria "at-risk for hyperbilirubinemia." Routine bilirubin measurements and 10-day follow-up were used to categorize neonates as; (1) normal (no hyperbilirubinemia, all bilirubins <95th percentile of Bhutani nomogram), (2) having hemolytic hyperbilirubinemia (bilirubin ≥95th percentile, DAT+, elevated retic, or G6PD+), or (3) having non-hemolytic hyperbilirubinemia.

RESULTS

386 neonates were enrolled. 321 (83%) did not develop hyperbilirubinemia and 65 (17%) did, of which 29 were judged hemolytic and 36 non-hemolytic. High ETCOc differentiated the hemolytic group (p < 0.001). First-day ETCOc correlated with bilirubin and with reticulocyte count (r = 0.896 and 0.878) and sensitivity and specificity for predicting hyperbilirubinemia were excellent (83% and 95%).

CONCLUSIONS

ETCO measurement in the first 48 hours after birth predicts hemolytic hyperbilirubinemia.

Neurodevelopmental outcome at 6 months of age of full-term neonates with hyperbilirubinemia necessitating exchange transfusion

BACKGROUND

Bilirubin neurotoxicity involves a spectrum of varying severity that could result in adverse long-term sequelae.

AIMS

To compare the neurodevelopmental outcome of full-term neonates who underwent exchange transfusion with those who did not.

STUDY DESIGN

A retrospective cohort study.

SUBJECTS

This study included a retrospective review of records of sixty neonates who were matched in admission ages and serum bilirubin levels and the comparison groups were those who received an exchange transfusion (n = 30) versus those where exchange transfusion was planned, but the bilirubin levels dropped sufficiently during the period where the exchange blood was being prepared (n = 30). History, clinical examination, and laboratory investigations were documented.

OUTCOME MEASURES

Neurodevelopmental outcome, at 6 months of age, using Bayley scales of infant development was assessed.

RESULTS

The exchange group had statistically significant lower cognitive scores (p-value 0.005). The higher the rate of bilirubin decline, the better the language and motor scores in the phototherapy group (p-values 0.020 and 0.024 respectively). Infants with longer duration to exchange transfusion had lower cognitive, language, and motor scores (p-values 0.01, 0.001, and 0.003 respectively).

CONCLUSIONS

Slower rates of bilirubin decline and longer duration before intervention increase the chances of adverse neurodevelopmental outcomes.

Factors associated with neonatal jaundice among neonates admitted at referral hospitals in northeast Ethiopia: a facility-based unmatched case-control study

BACKGROUND

Neonatal jaundice is a significant contributor to illness and death in newborns, leading to frequent admissions to neonatal intensive care units. To better understand this issue, a study was conducted to identify the factors contributing to neonatal jaundice among newborns admitted to Dessie and Woldia comprehensive specialized hospitals in northeast Ethiopia.

METHODS

The study took place from April 1 to May 30, 2022, using unmatched case-control design. A total of 320 neonates paired with their mothers were involved, including 64 cases and 256 controls. Data were collected through a structured interviewer-administered questionnaire and a review of medical records. The collected data were analyzed using SPSS Version 23, and a multivariate logistic regression model was employed to understand the relationship between independent factors and the occurrence of neonatal jaundice. Statistical significance was determined at a threshold of P value less than 0.05.

RESULTS

The study findings revealed that maternal age over 35 years, residing in urban areas [adjusted odds ratio (AOR) = 2.4, 95% confidence interval (CI): 1.23, 4.82], male gender (AOR = 4.3, 95% CI: 1.90, 9.74), prematurity (AOR = 3.9, 95% CI: 1.88, 8.09), and ABO incompatibility (AOR = 2.6, 95% CI: 1.16, 5.96) were significant determinants of neonatal jaundice. Conversely, the study indicated that cesarean birth was associated with a 76% lower likelihood of infant jaundice compared to vaginal delivery (AOR = 0.24, 95% CI: 0.08, 0.72).

CONCLUSION

To prevent, diagnose, and treat neonatal jaundice effectively, efforts should primarily focus on managing ABO incompatibility and early detection of prematurity. Additionally, special attention should be given to neonates born through vaginal delivery, those with mothers over 35 years old, and those residing in urban areas, as they are at higher risk of developing newborn jaundice. Close monitoring of high-risk mother-infant pairs during the antenatal and postnatal periods, along with early intervention, is crucial for reducing the severity of neonatal jaundice in this study setting.

A "Gold Standard" Test for Diagnosing and Quantifying Hemolysis in Neonates and Infants

Identifying "gold standard" diagnostic tests can promote evidence-based neonatology practice. Hemolysis is a pathological shortening of the erythrocyte lifespan, differing from erythrocyte senescence in responsible mechanisms and clinical implications. Diagnosing hemolysis goes beyond a binary (yes vs. no) determination. It is characterized according to magnitude, and as acute vs. chronic, and genetically based vs. not. For neonates with significant hyperbilirubinemia or anemia, detecting hemolysis and quantifying its magnitude provides diagnostic clarity. The 2022 American Academy of Pediatrics (AAP) Clinical Practice Guideline on management of hyperbilirubinemia in the newborn states that hemolysis is a risk factor for developing significant hyperbilirubinemia and neurotoxicity. The guideline recommends identifying hemolysis from any cause, but specific guidance is not provided. A spectrum of laboratory tests has been endorsed as diagnostic methods for hemolysis. Herein we examine these laboratory tests and recommend one as the "gold standard" for diagnosing and quantifying hemolysis in neonates and infants.

Impact of Protein Binding Capacity and Daily Dosage of a Drug on Total Serum Bilirubin Levels in Susceptible Infants

Hyperbilirubinemia is a common pathological condition in neonates. Free bilirubin can penetrate the blood-brain barrier (BBB), which can lead to bilirubin neurotoxicity. In the context of predicting the risk of bilirubin neurotoxicity, although the specificity and sensitivity of free bilirubin levels are higher than those of total serum bilirubin (TSB), free bilirubin is not widely monitored in clinical practice. The threshold TSB levels at which phototherapy must be administered have been established previously. However, TSB levels are not well correlated with neurodevelopmental outcomes. Currently, TSB levels are commonly used to guide phototherapy for neonatal hyperbilirubinemia. Some clinical drugs can displace bilirubin from its albumin-binding sites, and consequently upregulate plasma bilirubin. Daily dosages play a vital role in regulating bilirubin levels. A drug with both a high protein binding capacity and high daily dosage significantly increases bilirubin levels in infants. Premature or very low birth weight (VLBW) infants are vulnerable to the upregulation of bilirubin levels as they exhibit the lowest reserve albumin levels and consequently the highest bilirubin toxicity index. Because bilirubin is involved in maintaining the balance between pro-oxidant and antioxidant agents, the downregulation of bilirubin levels is not always desirable. This review provides insights into the impact of protein binding capacity and daily dosage of drugs on the bilirubin levels in susceptible infants.

A Novel Drug with Potential to Treat Hyperbilirubinemia and Prevent Liver Damage Induced by Hyperbilirubinemia: Carbon Dots Derived from Platycodon grandiflorum

Platycodon grandiflorum (PG) is a traditional Chinese medicine with a long history, but its active compounds have not been reported. In this study, novel carbon dots (CDs), PG-based CDs (PGC-CDs), were discovered and prepared from PG via calcinations and characterized by transmission electron microscopy; high-resolution transmission electron microscopy; X-ray diffraction, fluorescence, ultraviolet-visible, and Fourier-transform infrared spectrometers; X-ray photoelectron spectroscopy; and high-performance liquid chromatography. In addition, the safety and antioxidant activity of PGC-CDs was evaluated by RAW264.7 cells and LO2 cells. The therapeutic effects of PGC-CDs on hyperbilirubinemia and liver protection were evaluated in a bilirubin-induced hyperbilirubinemia mice model. The experiment confirmed that the diameter range of PGC-CDs was from 1.2 to 3.6 nm. PGC-CDs had no toxicity to RAW264.7 cells and LO2 cells at a concentration of 3.91 to 1000 µg/mL and could reduce the oxidative damage of cells caused by H2O2. PGC-CDs could inhibit the increase levels of bilirubin and inflammation factors and increase the levels of antioxidants and survival rate, demonstrating that PGC-CDs possessed anti-inflammatory and anti-oxidation activity. PGC-CDs may reduce the content of bilirubin, so as to reduce a series of pathological lesions caused by bilirubin, which has potential in treating hyperbilirubinemia and preventing liver damage induced by hyperbilirubinemia.

Higher ETCOc predicts longer phototherapy treatment in neonatal hyperbilirubinemia

Objective

This study aimed to evaluate the predictive performance of end-tidal carbon monoxide corrected to ambient carbon monoxide (ETCOc) values phototherapy in neonates with significant hyperbilirubinemia.

Methods

A prospective study was conducted on neonates with significant hyperbilirubinemia who received phototherapy between 3 and 7 days of life. The breath ETCOc and serum total bilirubin of the recruited infants were measured on admission.

Results

The mean ETCOc at admission in 103 neonates with significant hyperbilirubinemia was 1.70 ppm. The neonates were categorized into two groups: phototherapy duration ≤72 h (n = 87) and >72 h (n = 16) groups. Infants who received phototherapy for >72 h had significantly higher ETCOc (2.45 vs. 1.60, P = 0.001). The cutoff value of ETCOc on admission for predicting longer phototherapy duration was 2.4 ppm, with a sensitivity of 62.5% and specificity of 88.5%, yielding a 50% positive predictive value and a 92.7% negative predictive value.

Conclusion

ETCOc on admission can help predict the duration of phototherapy in neonates with hyperbilirubinemia, facilitate clinicians to judge disease severity, and make clinical communication easier and more efficient.

An End-Tidal Carbon Monoxide Nomogram for Term and Late-Preterm Chinese Newborns

OBJECTIVE

To establish a reference nomogram for end-tidal CO corrected for ambient CO (ETCOc) levels in term and late-preterm Chinese newborns and then assess its efficacy to identify hemolytic hyperbilirubinemia.

STUDY DESIGN

We conducted a prospective study by measuring concurrent ETCOc and total serum bilirubin (TSB) or transcutaneous bilirubin (TcB) levels collected postnatally at 12, 24, 48, 72, 96, and 120 hours of age. ETCOc at the 25th, 50th, 75th, and 95th percentiles at each epoch were used to construct the reference nomogram. We then explored the ability of predischarge ETCOc and TSB/TcB metrics to predict the development of hyperbilirubinemia requiring phototherapy in early postnatal period and jaundice readmission in late postnatal period.

RESULTS

Our nomogram, based on 990 measurements from 455 infants who were not nonhemolytic, displayed a steady line within 3 postnatal days, followed by a subsequent decline. From a cohort of infants with a serial ETCOc measurements (n = 130) and those readmitted (n = 21), we found that ETCOc and TSB/TcB ≥75th percentile can identify most hemolytic hyperbilirubinemia between 12 and 72 hours after birth with an area under the curve (AUC) of 0.741. An ETCOc ≥1.7 ppm alone between 96 and 120 hours after birth can identify most hemolytic hyperbilirubinemia with an AUC of 0.816. In addition, 90.5% of readmitted infants had an ETCOc ≥75th percentile.

CONCLUSIONS

An ETCOc reference nomogram during the first 5 postnatal days in nonhemolytic term and late-preterm newborns can be used to identify hemolytic hyperbilirubinemia requiring phototherapy in the early postnatal period and readmission in the late postnatal period.

Increased Total Serum Bilirubin Level Post-Ibuprofen Use Is Inversely Correlated with Neonates' Body Weight

Backgrounds: Drugs with the ability to displace bilirubin from albumin-binding sites subsequently leading to an increased bilirubin level may cause hyperbilirubinemia in neonates. Ibuprofen is commonly used to treat patent ductus arteriosus (PDA) in neonates, yet the use of ibuprofen has drawn mixed conclusions. We performed a retrospective study to determine how ibuprofen use influences the total serum bilirubin (TSB) level in neonates of differing birth weight (BW). Materials and methods: Neonates (including premature infants) born at Chang Gung Memorial Hospital, Taiwan during January 2004 to July 2020 were entered into this study. We recorded the phototherapy duration, including the initial day and end day, and determined the average influence of one-day phototherapy on TSB level. The highest monitored TSB level post-ibuprofen use minus the one measured prior to ibuprofen use was considered the TSB change following ibuprofen administration in this study, and the above-mentioned influence of daily phototherapy on the TSB level was used to correlate the results. Neonates with any of the following conditions were excluded: those who received ceftriaxone, those with intraventricular hemorrhage, and those infected with TORCH. Results: The average daily influence of phototherapy on the TSB level of neonates was −0.20 (−0.57~0.05) mg/dL, −0.28 (−0.84~0.13) mg/dL, −0.75 (−1.77~0.10) mg/dL, and −1.60 (−2.70~−0.50) mg/dL in neonates with BWs of <1 kg, 1−1.49 kg, 1.5−2.49 kg, and ≥2.5 kg, respectively, indicating that neonates with a BW ≥ 1.5 kg experienced a greater reduction in TSB level following phototherapy as compared with those with a BW < 1.5 kg. The average TSB increase following ibuprofen use in neonates was 3.38 ± 2.77 mg/dL, 2.04 ± 2.53 mg/dL, and 1.34 ± 2.24 mg/dL in neonates with BWs of <1 kg, 1−1.49 kg, and ≥1.5 kg, respectively, i.e., an elevated TSB change with a decreased neonate BW was noted post-ibuprofen use (p = 0.026, one-way analysis of variance (ANOVA)). Conclusions: As ibuprofen use is correlated with an apparent increase in TSB level in neonates with a lower BW, especially in those with a BW < 1 kg, iv acetaminophen can be an appropriate alternative to ibuprofen for ELBW neonates for the treatment of PDA if they are experiencing severe unconjugated hyperbilirubinemia.

Therapeutic efficacy and safety of Yinzhihuang granules with phototherapy in neonatal pathologic jaundice: An updated systematic review and meta-analysis

BACKGROUND

Yinzhihuang granule, consisting of extracts of Artemisia capillaris Thunb., Gardenia jasminoides Ellis, Lonicera japonica Thunb., and Scutellaria baicalensis Georgi is a well-known traditional Chinese patent medicine for patients with liver injury in China. However, the effects and safety of its use for pathologic jaundice in newborns require further systematic evaluation.

PURPOSE

To systematically evaluate the efficacy and safety of Yinzhihuang granules for the treatment of neonatal pathologic jaundice and to provide clinical evidence.

METHODS

Chinese databases (China Network Knowledge Infrastructure, Wan Fang Database, and VIP Database) and English databases (PubMed, EmBase, and the Cochrane Library) were thoroughly investigated through screening randomized controlled trials on Yinzhihuang granules for neonatal pathologic jaundice from the establishment of all databases to November 18, 2021. A meta-analysis was performed for selected data using STATA software. TSA software was used for trial sequential analyses of the total effective rate and adverse reactions.

RESULTS

A total of 19 trials and 2,221 newborns with pathologic jaundice were included in this study. Outcome measures of clinical efficacy in the experimental group were higher than in controls, including total bilirubin (WMD = -30.34, 95% CI = -35.44 to -25.23, p < 0.001), direct bilirubin (WMD = -15.03, 95% CI = -23.54 to -6.52, p < 0.001), indirect bilirubin (WMD = -11.22, 95% CI = -17.50 to -4.95, p < 0.001), recovery time (WMD = -2.96, 95% CI = -3.92 to -2.00, p < 0.001), hospitalization time (WMD = -3.83, 95% CI = -4.89 to -2.76, p < 0.001), and liver function indices. There were statistically significant differences between the two groups. Likewise, the incidence of adverse reactions, including diarrhea, erythra, and fever decreased remarkably in the trial group (RR = 0.44, 95% CI =  0.33 to 0.59, p < 0.001). Publication bias did not exist. We verified the efficacy and safety of Yinzhihuang granules with phototherapy for pathologic jaundice in newborns according using TSA analysis.

CONCLUSION

Yinzhihuang granules with phototherapy for neonatal pathologic jaundice are more effective than phototherapy alone. The incidence of ADRs does not increase with the application of Yinzhihuang granules. Due to the heterogeneity across the included studies, additional multicenter clinical trials with follow-ups are needed to confirm our findings.

Reference intervals for end-tidal carbon monoxide of preterm neonates

OBJECTIVES

We constructed reference intervals for end-tidal carbon monoxide (ETCOc) levels of neonates 28 ^0/7 to 34 ^6/7 weeks gestation in order to assess hemolytic rate.

STUDY DESIGN

This is a prospective four-NICU study in Bangkok, Thailand, and Utah, USA.

RESULTS

Of 226 attempted measurements, 92% were successful. Values from day 1 through 28 were charted and upper (>95th percentile) reference interval limits calculated. During the entire 28 days, the ETCOc upper reference intervals from babies in Bangkok were higher than those in Utah (p < 0.01). No differences were found due to sex, or earliest vs. latest gestation at birth (both p > 0.1). Similar to term neonates, preterm neonates in Bangkok and Utah had higher ETCOc values during the first 48 h after birth than thereafter (p < 0.01).

CONCLUSIONS

Using this methodology, and the reference interval chart, the hemolytic rate of preterm infants ≥28 weeks can be assessed.

Highly Efficient Adsorption of Bilirubin by Ti3 C2 Tx MXene

We discovered that the 2D Ti₃ C₂ T_x MXene sheet displays an ultra-high removal capability for bilirubin (BR). In particular, MXene shows 47.6 times higher removal efficiency over traditional activated carbon absorbents. The effect of MXene on the removal rate of BR in BR solution containing different concentrations of bovine serum albumin (BSA) was studied. The adsorption capacity of BSA for BR at high concentration of 5 g L^-1 was about 85% of the best adsorption capacity. The MXene before and after adsorption was characterized by SEM, FT-IR and XPS. Furthermore, MXene beads were prepared, and the hemoperfusion simulation experiment was carried out. The results show that the adsorption capacity of MXene for bilirubin can reach 1192.9 mg g^-1 . This study suggests that MXene may be promising in the treatment of hyperbilirubinemia.