The utility of inpatient rebound bilirubin levels in infants readmitted after birth hospitalization for hyperbilirubinemia

Risk Factors and Predictors of Rebound Hyperbilirubinemia in a Term and Late-Preterm Infant with Hemolysis

OBJECTIVE

This study aimed to assess the incidence and predictors of rebound in term and late-preterm infants with hemolytic hyperbilirubinemia postphototherapy.

STUDY DESIGN

A 4-year retrospective data analysis of neonates with hemolytic indirect hyperbilirubinemia admitted to the neonatal intensive care unit (NICU) of Medina Maternity and Children's Hospital was conducted. Bilirubin rebound was defined as the return of total serum bilirubin (TSB) to phototherapy threshold within 72 hours of postphototherapy.

RESULTS

Of 386 identified neonates; 44 (11%) experienced rebound. Neonates in the rebound group demonstrated significantly higher levels of peak TSB, TSB at discontinuation of phototherapy, and lower value of relative TSB (difference between TSB at phototherapy termination and the American Academy of Pediatrics [AAP] threshold for phototherapy at concurrent age) compared with nonrebound group (p-value: <0.001, <0.001, and 0.007, respectively). Lower value of relative TSB at stoppage of phototherapy was the single independent predictor for rebound hyperbilirubinemia by mutivariate regression (p < 0.001). A cut-off value for relative TSB at stoppage of phototherapy of 190 µmol/L had 98% sensitivity and 32% specificity to predict rebound hyperbilirubinemia.

CONCLUSION

Relative TSB at phototherapy termination is the best predictor for postphototherapy rebound hyperbilirubinemia in neonates with hemolytic etiology.

KEY POINTS

· 11% of neonates showed postphototherapy rebound.. · The relative TSB at stoppage of phototherapy is the best predictor for rebound hyperbilirubinemia.. · The first cohort to assess rebound in neonates with hemolysis..

Validation of published rebound hyperbilirubinemia risk prediction scores during birth hospitalization after initial phototherapy: a retrospective chart review

BACKGROUND

Hyperbilirubinemia commonly affects newborns and may lead to neurotoxicity if untreated. Neonates can experience rebound hyperbilirubinemia (RHB), defined as elevated bilirubin levels requiring re-initiation of treatment. Although studies have formulated risk prediction scores, they lack external validation. In this study, we examine the discrimination and calibration performance of risk prediction scores for RHB, to provide external validation.

METHODS

We reviewed charts of neonates born ≥35 weeks of gestation between January 2015 and December 2019 receiving phototherapy at birth hospitalization. We plotted predicted probabilities against observed outcome proportions to assess model calibration and evaluated discrimination using area under the receiver operating characteristic (AUROC) curves. Odds ratios (ORs) were estimated to evaluate variables associated with RHB.

RESULTS

Of the 271 infants identified, 24% developed RHB. Two- and three-variable prediction scores had lower discrimination in our cohort with AUROC of 0.662 (95% CI 0.590-0.735) and 0.691 (95% CI, 0.619-0.763) compared to 0.876 (95% CI 0.854-0.899) and 0.881 (95% CI 0.859-0.903), respectively, in the published studies. Estimated ORs confirm associations between RHB and variables included in prediction scores.

CONCLUSIONS

Current prediction models for RHB have unclear clinical utility in our patient population. Additional studies are required to further validate these scores.

IMPACT

Describes performance characteristics of two- and three-variable risk prediction scores that lack external validation beyond the initial study cohort. Our findings suggest unclear clinical utility in our clinical population of neonates during birth hospitalization, with lower performance of these prediction scores than observed in the derivation cohort. Odds ratios estimated by logistic regression in our study cohort provide further evidence that variables in published risk prediction scores are associated with rebound hyperbilirubinemia. Further studies are required to externally validate these risk prediction scores and to assess their generalizability.

Decreasing Laboratory Testing for Neonatal Jaundice Through Revision of a Clinical Practice Pathway

OBJECTIVES

The purpose of this study was to minimize unnecessary laboratory services for hospitalized neonates with hyperbilirubinemia by revising a local clinical practice pathway (CPP).

METHODS

A retrospective cohort study was performed to compare the number of laboratory tests and blood draws in patients hospitalized with neonatal hyperbilirubinemia before and after implementation of a revised CPP. The study included infants with neonatal hyperbilirubinemia <14 days old admitted after their birth hospitalization between April 2017 and October 2019. Primary outcome measures included the total number of blood draws and the number of laboratory tests obtained per patient and length of stay. Secondary outcome measures included 7-day readmission rate, charges, and discharge bilirubin level.

RESULTS

The median number of blood draws per patient after implementation of the CPP decreased to 2 (interquartile range [IQR], 2-3) compared with 3 (IQR, 2-3) before implementation (Poisson model-based estimated mean difference, 1.1; 95% confidence interval, 1.0-1.3; P = .018). The median number of laboratory tests per patient after implementation decreased from 4 (IQR, 3-6) to 3 (IQR, 2-4; Poisson model-based estimated mean difference, 1.3; 95% confidence interval, 1.2-1.5; P < .0001). There was no significant change in length of stay, readmission rate, charges, or discharge bilirubin level.

CONCLUSIONS

Implementation of a revised CPP was associated with a significant decrease in the number of blood draws and laboratory tests per patient for infants admitted to the hospital for neonatal hyperbilirubinemia.

Treatment practices and implementation of guidelines for hyperbilirubinemia and rebound hyperbilirubinemia

BACKGROUND

Hyperbilirubinemia (HB), defined as elevated total serum bilirubin (TSB) levels, commonly affects neonates and requires prompt treatment to prevent neurological complications. Up to 10%of neonates experience rebound hyperbilirubinemia (RHB), requiring re-initiation of treatment. Unfortunately, treatment guidelines lack practical recommendations surrounding subthreshold phototherapy, treatment termination, and RHB investigations. We examined local management practices for HB and RHB treatment in a well newborn nursery. As a secondary aim, we investigated the association between treatment practices and RHB rates.

METHODS

Retrospective chart review identified neonates treated for hyperbilirubinemia between January 2015 and December 2019 during their birth hospitalization at a tertiary care centre. Standardized data collection sheets were used to record treatment parameters.

RESULTS

Over the 5-year period, there were 9683 births and 305 (3.15%) neonates received phototherapy. Of the treated cases, 20-25%were subthreshold to practice guideline values. Upon treatment termination 25-55%of cases had TSB levels within 3 mg/dL, which may increase the risk of RHB. In our cohort, 20.3%of treated cases experienced one episode of RHB and 3.9%experienced two episodes of RHB. Although clinicians evaluated neonates for RHB 0-12 hours following treatment termination prior to discharge, many cases were identified in outpatient settings and required re-admission for phototherapy.

CONCLUSION

When managing HB and RHB, treatment practices such as when to terminate treatment in relation to threshold values, and timing of RHB investigations, are largely inconsistent amongst clinicians. Future studies are required to better understand the landscape of hyperbilirubinemia treatment beyond initiation of phototherapy.

Neonatal Indirect Hyperbilirubinemia

Neonatal indirect hyperbilirubinemia (IHB) is caused by an imbalance in bilirubin production and elimination. Approximately 60% of term and 80% of preterm infants develop jaundice in the first week of age. This review seeks to provide the reader with a thorough understanding of the physiology of bilirubin, etiology of IHB, and management of severe IHB. Phototherapy and exchange transfusion remain the mainstays of treatment for severe IHB. Noninvasive screening tools, innovative treatments, and a better understanding of how prematurity and genetics contribute to severe IHB have improved our understanding of IHB and may help eliminate the hazards associated with severe IHB, including kernicterus spectrum disorder.

Predictive Models for Neonatal Follow-Up Serum Bilirubin: Model Development and Validation

Background

Hyperbilirubinemia affects many newborn infants and, if not treated appropriately, can lead to irreversible brain injury.

Objective

This study aims to develop predictive models of follow-up total serum bilirubin measurement and to compare their accuracy with that of clinician predictions.

Methods

Subjects were patients born between June 2015 and June 2019 at 4 hospitals in Massachusetts. The prediction target was a follow-up total serum bilirubin measurement obtained <72 hours after a previous measurement. Birth before versus after February 2019 was used to generate a training set (27,428 target measurements) and a held-out test set (3320 measurements), respectively. Multiple supervised learning models were trained. To further assess model performance, predictions on the held-out test set were also compared with corresponding predictions from clinicians.

Results

The best predictive accuracy on the held-out test set was obtained with the multilayer perceptron (ie, neural network, mean absolute error [MAE] 1.05 mg/dL) and Xgboost (MAE 1.04 mg/dL) models. A limited number of predictors were sufficient for constructing models with the best performance and avoiding overfitting: current bilirubin measurement, last rate of rise, proportion of time under phototherapy, time to next measurement, gestational age at birth, current age, and fractional weight change from birth. Clinicians made a total of 210 prospective predictions. The neural network model accuracy on this subset of predictions had an MAE of 1.06 mg/dL compared with clinician predictions with an MAE of 1.38 mg/dL (P<.0001). In babies born at 35 weeks of gestation or later, this approach was also applied to predict the binary outcome of subsequently exceeding consensus guidelines for phototherapy initiation and achieved an area under the receiver operator characteristic curve of 0.94 (95% CI 0.91 to 0.97).

Conclusions

This study developed predictive models for neonatal follow-up total serum bilirubin measurements that outperform clinicians. This may be the first report of models that predict specific bilirubin values, are not limited to near-term patients without risk factors, and take into account the effect of phototherapy.

Risk factors for readmission for phototherapy due to jaundice in healthy newborns: a retrospective, observational study

BACKGROUND

The guidelines of the American Academy of Pediatrics (AAP) for monitoring neonatal jaundice recommend universal postnatal screening for hyperbilirubinemia within 48 h from discharge. We observed that neonate with low-risk jaundice were more likely to be readmitted to hospital for phototherapy compared to neonate with high-risk jaundice. The aim of this study was to identify additional factors that increase the risk for jaundice-related readmission.

METHODS

This observational case-control study was performed on 100 consecutive neonates with jaundice who were readmitted to hospital for phototherapy treatment and were compared to 100 neonates with jaundice during hospitalization who were not readmitted after discharge. The data retrieved from the medical records of all participants included maternal characteristics, delivery type and noteworthy events, gestational age at delivery, birth weight and weight loss, neonate physical findings, Apgar scores, laboratory findings, length of hospital stay, and administration of phototherapy during hospitalization. The length of time since discharge and readmission for jaundice was also recorded.

RESULTS

The risk of readmission decreased by 48% [odds ratio (OR) =0.52; 95% confidence interval (CI) 0.341-0.801] with every day added to the original hospitalization stay, and by 71% (OR = 0.29; 95% CI 0.091-0.891) if phototherapy had been administered during postnatal hospitalization. In contrast, the risk increased by 28% (OR = 1.28; 95% CI 1.164-1.398) with every elevation by 1% in hematocrit, and by 2.78 time (95% CI 1.213-6.345; p = 0.0156) when the delta in infant weight was > 5% (the difference between birth weight and weight at discharge during the postnatal hospitalization).

CONCLUSIONS

The risk factors for readmission, such as substantial weight loss (> 5% difference between birth and discharge) and elevated hematocrit should be taken into account in the decision to discharge neonate with low-risk jaundice. The AAP guidelines for decreasing readmission rates of neonatal jaundice by postnatal screening for hyperbilirubinemia alone may be more appropriate for neonate with high-risk jaundice.

Newborns bilirubin concentration determined by different methods in relation to hematocrit and albumin level

Background

Monitoring of bilirubin is essential during early neonatal life. Bilirubin in high concentration is toxic to the brain and might cause irreversible neurological damage. Several different methods for bilirubin determination are available nowadays, but inconsistent results may be obtained. The study aimed to compare dry chemistry methods with vanadate oxidation method for bilirubin determination in relation to hematocrit and albumin level in neonates and infants.

Methods

The study included 98 consecutive serum samples from newborns and infants (47 boys and 51 girls, mean age 19 ± 15 days) treated in the University Children's Hospital in Krakow. Total bilirubin (TBil) and neonatal bilirubin (NBil) concentration were measured by dry chemistry analyser (Vitros 4600, Ortho Clinical Diagnostics Inc.). Total bilirubin (TBil_V) was also measured using vanadate oxidation method (Cormay, Poland). Albumin concentration and blood morphology have been routinely determined in all children.

Results

No significant differences between the mean value of NBil (69.00 ± 67.76 μmol/L), TBil (81.26 ± 70.13 μmol/L) and TBilV (75.90 ± 60.62 μmol/L) were noticed. High coefficient correlation between NBil and TBil as well as between NBil and TBil_V were noticed (Pearson's analysis, r = 0.99, r = 0.97, respectively; p < 0.0001 in both cases). There was a positive correlation between the difference (TBil_V - NBil) and hematocrit (p < 0.009, r = 0.2664).

Conclusions

In newborns and infants the same method for bilirubin determination should be used when the concentration of bilirubin is monitored. When using vanadate oxidation method for bilirubin determination, hematocrit value should be taken into account when results are interpreted.

Incidence and risk factors of post-phototherapy neonatal rebound hyperbilirubinemia

BACKGROUND

To determine the incidence and risk factors of post-phototherapy rebound hyperbilirubinemia because data about bilirubin rebound in neonates are lacking and few studies have concerned this condition.

METHODS

A prospective observational study was conducted on 500 neonates with indirect hyperbilirubinemia who were treated according to standard guidelines. Total serum bilirubin (TSB) was measured at 24-36 h after phototherapy; significant bilirubin rebound (SBR) is considered as increasing TSB that needs reinstitution of phototherapy.

RESULTS

A total of 124 (24.9%) neonates developed SBR with TSB increased by 3.4 (2.4-11.2) mg/dL after stopping phototherapy. Multiple logistic regression model revealed the following significant risk factors for rebound: low birth weight (B = 1.3, P <  0.001, OR 3.5), suspected sepsis (B = 2.5, P <  0.001, OR 12.6), exposure to intensive phototherapy (B =  0.83, P =  0.03, OR 2.3), hemolysis (B =  1.2, P <  0.001, OR 3.1), high discharge bilirubin level (B =  0.3, P =  0.001, OR 1.3), and short duration of conventional phototherapy (B =  - 1.2, P <  0.001, OR 0.3).

CONCLUSIONS

SBR should be considered in neonates with hemolysis, low birth weight, suspected sepsis, short duration of conventional phototherapy, exposure to intensive phototherapy, and relatively high discharge TSB. These risk factors should be taken into account when planning post-phototherapy follow-up.