Transcutaneous bilirubin levels in newborns <35 weeks' gestation

The Accuracy of Transcutaneous Bilirubin as a Screening Test in Preterm Infants

OBJECTIVE

To determine the accuracy of transcutaneous bilirubin (TcB) to predict total serum bilirubin (TSB) in preterm infants across gestational age (GA) ranges and to calculate the cost-effectiveness of TcB as the primary screening test of choice for neonatal jaundice in neonatal intensive care unit (NICU) settings.

METHODS

Single-center retrospective study of infants aged ≤ seven days admitted to the NICU over a six-month period with a paired TSB and TcB, with or without phototherapy as part of their routine clinical care. Infants were divided into GA-specific groups as term, late preterm, moderate preterm, and very preterm. Measurement bias (bias=TSB-TcB) was calculated on the paired TSB and TcB values, and a Bland-Altman analysis was carried out. The impacts of additional infant-specific variables on the bias were assessed with univariate and multivariate linear regression techniques. The potential direct cost savings associated with the use of TcB as the primary screening test were calculated.

RESULTS

A total of 263 paired TSB and TcB samples from 95 patients were included (130 paired samples from term (n=60), 75 from late preterm (n=21), 27 from moderate preterm (n=7), and 31 from very preterm (n=7)). The mean paired measurement bias across all the GA groups was -0.9 ± 2.9 mg/dL. The sensitivity and specificity of TcB in GA < 35 weeks were 92% and 62%, respectively. A conservative estimate of a one-third reduction in TSB measurement by using TcB as the primary screening test will have a direct cost saving of $3,148 over a six-month period.

CONCLUSION

Our data suggest that TcB is a safe and potentially cost-effective screening test for jaundice across GA groups.

Transcutaneous bilirubin levels in extremely preterm infants less than 30 weeks gestation

OBJECTIVE

The primary objective of this study was to determine the relationship between transcutaneous bilirubin (TcB) levels and total serum bilirubin (TSB) levels in extremely preterm infants.

STUDY DESIGN

We conducted a prospective multicenter study of extremely preterm infants less than 30 weeks gestation in California. Difference between paired TcB and TSB values were compared based on gestational age, birth weight, maternal race/ethnicity, chronological age as well as during and after phototherapy.

RESULTS

TSB values ranged from 0 to 12.6 mg/dl and the TcB values ranged from 0 to 14.2 mg/dl. TSB was predicted with a high degree of accuracy at TSB = 2.37 + 0.54 (TcB) with r = 0.786. There was good correlation across gestational age, birth weight, race/ethnic, chronological age subgroups as well as during and after phototherapy.

CONCLUSION

Our study supports the use of TcB as a screening tool for monitoring jaundice in extremely preterm infants.

Screening methods for neonatal hyperbilirubinemia: benefits, limitations, requirements, and novel developments

Severe neonatal hyperbilirubinemia (SNH) is a serious condition that occurs worldwide. Timely recognition with bilirubin determination is key in the management of SNH. Visual assessment of jaundice is unreliable. Fortunately, transcutaneous bilirubin measurement for screening newborn infants is routinely available in many hospitals and outpatient settings. Despite a few limitations, the use of transcutaneous devices facilitates early recognition and appropriate management of neonatal jaundice. Unfortunately, however, advanced and often costly screening modalities are not accessible to everyone, while there is an urgent need for inexpensive yet accurate instruments to assess total serum bilirubin (TSB). In the near future, novel icterometers, and in particular optical bilirubin estimates obtained with a smartphone camera and processed with a smartphone application (app), seem promising methods for screening for SNH. If proven reliable, these methods may empower outpatient health workers as well as parents at home to detect jaundice using a simple portable device. Successful implementation of ubiquitous bilirubin screening may contribute substantially to the reduction of the worldwide burden of SNH. The benefits of non-invasive bilirubin screening notwithstanding, any bilirubin determination obtained through non-invasive screening must be confirmed by a diagnostic method before treatment. IMPACT: Key message: Screening methods for neonatal hyperbilirubinemia facilitate early recognition and timely treatment of severe neonatal hyperbilirubinemia (SNH). Any bilirubin screening result obtained must be confirmed by a diagnostic method. What does this article add to the existing literature? Data on optical bilirubin estimation are summarized. Niche research strategies for prevention of SNH are presented. Impact: Transcutaneous screening for neonatal hyperbilirubinemia contributes to the prevention of SNH. A smartphone application with optical bilirubin estimation seems a promising low-cost screening method, especially in low-resource settings or at home.

Transcutaneous Bilirubin Monitoring in Preterm Infants of 23 to 34 Weeks' Gestation

OBJECTIVE

 The study aimed to evaluate the validity of transcutaneous bilirubin (TcB) measurements at three sites in premature infants born at 23^0/7 to 34^6/7 weeks' gestational age (GA) compared with total serum bilirubin (TSB) measurements.

STUDY DESIGN

 A prospective study was conducted at Banner - University Medical Center Phoenix, where informed consent was obtained from the infant's parent or legally authorized representative. Cohort A was comprised of infants 23^0/7 to 28^6/7 weeks' GA and Cohort B contained subjects 29^0/7 to 34^6/7 weeks' GA. Baseline TSB measurements were collected at approximately 24 hours of life, as the standard of care and the TcB measurements were obtained from the sternum, interscapular, and buttock areas at approximately ± 30 minutes from collection of the TSB. Statistical analysis of measurements including sensitivity, specificity, positive, and negative predictive values, and the area under the receiver operator characteristic curve (AUROC) were performed.

RESULTS

 A total of 166 infants were included in the study population. Cohort A consisted of 41 subjects and Cohort B contained 125 subjects. The results showed that baseline TcB measurements from the interscapular area were the most sensitive and specific with TSB levels >5.0 mg/dL in Cohort A. Baseline TcB measurements from the sternum demonstrated greatest sensitivity and specificity when the TSB level was >8.0 mg/dL in Cohort B. In general, each of the three sites in both cohorts demonstrated excellent AUROCs and negative predictive values.

CONCLUSION

 The use of a TcB meter in preterm infants can be a reliable noninvasive screening tool for hyperbilirubinemia, and it may be beneficial in decreasing painful stimuli and iatrogenic blood loss when used as an adjunct to TSB monitoring.

KEY POINTS

· Interscapular TcB is sensitive/specific in 23 to 29 weeks' GA.. · Sternal TcB is sensitive/specific in 29 to 35 weeks' GA.. · TcB readings are reliable in preterm infants.. · TcB is reliable when serum bilirubin is >5.0 mg/dL..

Reliability of transcutaneous bilirubin determination based on skin color determined by a neonatal skin color scale of our own

Measurement of transcutaneous bilirubin (TcB) is widely used to estimate serum bilirubin (SB). However, its reliability depending on skin tone is still controversial. Ethnic classification does not correlate well with skin tone. We aimed to determine the reliability of transcutaneous bilirubin in a multiethnic population based on skin color according to our neonatal skin color scale. We conducted a prospective, observational study comparing SB and TcB among different skin colors. With the blood sample routinely obtained at 48-72 h for the screening of inborn errors of metabolism, we determined SB and TcB with a jaundice meter. We obtained data from 1359 newborns (color 1 337, color 2 750, color 3 249, color 4 23) and analyzed 1549 dyads SB/TcB. Correlation between TcB and serum bilirubin was very good (R² = 0.908-0.956), globally and by color group, with slight differences between darker and lighter skin colors. Bland-Altman plots showed different mean bias depending on skin color. Conclusions: Our study not only supports the reliability of TcB to assess SB regardless of skin color, but also supports the fact that TcB tends to overestimate SB in a higher degree in dark-skinned neonates. This may help reduce the number of blood samples for newborns. What is Known: • Jaundice meters are extensively used to diagnose neonatal hyperbilirubinemia, although controversies exist on their reliability depending on skin color. • Only a few studies have analyzed their accuracy in multiethnic populations, but none has used a validated neonatal skin color scale. What is New: • We verified correlation between serum and transcutaneous bilirubin in a multiethnic population depending on skin color after classifying our neonates into color groups with our own validated neonatal skin color scale.

Decision Accuracy and Safety of Transcutaneous Bilirubin Screening at Intermountain Healthcare

OBJECTIVE

To quantify the risk that transcutaneous bilirubin (TcB) screening would fail to recommend phototherapy for a neonate who would have qualified for it if total serum bilirubin (TSB) screening were used.

STUDY DESIGN

We conducted a quality improvement project where simultaneous TcB and TSB were obtained on neonates ≥35 weeks of gestation during birth hospitalizations in our hospital system. Using our Utah bilirubin management algorithm, we quantified the risk that TcB screening would fail to identify the need for a confirmatory TSB when TSB screening alone would have revealed that phototherapy was indicated.

RESULTS

In 3 hospitals, we obtained 727 paired TcB/TSB measurements. Two instances utilized a blood gas radiometer for TSB, and 725 utilized the clinical laboratory-based TSB method. One of the 727 instances had a TcB indicating NO PHOTOTHERAPY, when the simultaneous TSB indicated PHOTOTHERAPY NEEDED. The TSB from that instance was 1 of the 2 from the blood gas radiometer. We estimate the risk of such an error occurring is 1.4 per 1000 TcB measurements (95% CI 0.03-7.6 per 1000). When only the laboratory TSB is used, we estimate the risk of such an error occurring to be 0 per 1000 TcB measurements (95% CI 0.0-5.1 per 1000).

CONCLUSIONS

Using TcB for screening at the birth hospital can identify those qualifying for phototherapy, using the Utah guidelines, with 1 of 727 neonates with a blood gas bilirubin and none of 725 with a laboratory-based analysis misidentified as not needing phototherapy when by TSB they did.

Transcutaneous versus Total Serum Bilirubin Measurements in Preterm Infants

INTRODUCTION

Transcutaneous bilirubin (TcB) measurement offers a noninvasive approach for bilirubin screening; however, its accuracy in preterm infants is unclear. This study determined the agreement between TcB and total serum bilirubin (TSB) among preterm infants.

METHODS

A multisite prospective cohort study was conducted at 3 NICUs in Ontario, Canada, September 2016 to June 2018. Among 296 preterm infants born at 240/7 to 356/7 weeks, 856 TcB levels were taken at the forehead, sternum, and before and after the initiation of phototherapy with TSB measurements. Bland-Altman plots and 95% limits of agreement (LOA) expressed agreement between TcB and TSB.

RESULTS

The overall mean TcB-TSB difference was -24.5 μmol/L (95% LOA -103.3 to 54.3), 1.6 μmol/L (95% LOA -73.4 to 76.5) before phototherapy, and -31.1 μmol/L (95% LOA -105.5 to 43.4) after the initiation of phototherapy. The overall mean TcB-TSB difference was -15.2 μmol/L (95% LOA -86.8 to 56.3) at the forehead and -24.4 μmol/L (95% LOA -112.9 to 64.0) at the sternum. The mean TcB-TSB difference was -31.4 μmol/L (95% LOA -95.3 to 32.4) among infants born 24-28 weeks, -25.5 μmol/L (95% LOA -102.7 to 51.8) at 29-32 weeks, and -15.9 μmol/L (95% LOA -107.4 to 75.6) at 33-35 weeks. Measures did not differ by maternal ethnicity.

CONCLUSION

Among preterm infants, TcB may offer a noninvasive, immediate approach to screening for hyperbilirubinemia with more careful use in preterm infants born at <33 weeks' gestation, as TcB approaches treatment thresholds. Its underestimation of TSB after the initiation of phototherapy warrants the use of TSB for clinical decision-making after the initiation of phototherapy.

The accuracy of transcutaneous bilirubin to identify hyperbilirubinemia in jaundiced neonates

OBJECTIVE

To compare transcutaneous bilirubin (TcB) to total serum bilirubin (TSB) in jaundiced neonates by using a JM-103 bilirubinometer.

METHODS

We conducted a retrospective study in jaundiced infants ≥35 weeks' gestation. Infants' and maternal information, TcB measurements, and TSB levels were collected. The correlation and consistency between TcB and TSB were analyzed by Pearson's correlation analysis and the Bland-Altman plot. Multivariate regression analysis was used to identify characteristics associated with the difference between TcB and TSB, underestimation by TcB and overestimation by TcB.

RESULTS

A total of 787 paired samples were collected. There was a strong correlation between TcB and TSB with a Pearson correlation coefficient of 0.708 (p < .001). In preterm infants, outpatients and infants with high TSB levels, the TcB measurements were less precise. The TcB-TSB difference was significantly associated with gender, maternal hypertension disease, ABO hemolytic disease, and outpatient setting (p < .05). Only the outpatient setting had statistical significance in the underestimation of TSB ≥2 mg/dL.

CONCLUSIONS

Generally, TcB by a JM-103 bilirubinometer had a good correlation and consistency with the TSB values. However, small for gestational age, postnatal age of hour, ABO hemolytic disease, and outpatient setting may lead to inconsistencies between the TcB and TSB.

Predictability of transcutaneous bilirubinometry in late preterm and term infants at risk for pathological hyperbilirubinemia

BACKGROUND

The aim was to assess the predictability of transcutaneous bilirubinometry in late preterm and term neonates at risk for pathological hyperbilirubinemia, and to identify the neonatal population in which transcutaneous bilirubin most accurately predicts serum bilirubin level (SB, mg/dl).

METHODS

The correlations between transcutaneous bilirubin (TCB, mg/dl) and SB in different neonatal population subsets; and between ΔTSB (TCB-SB) and relevant neonatal variables and clinical groups were analyzed.

RESULTS

TCB correlated with SB (r = 0.82, p < 0.05) in the cohort (n = 350) and in population subsets (r = 0.81-0.9, p < 0.001). Black infants with gestational age (GA) >35 weeks and chronological age (CA) >3 days recorded strongest correlation (r = 0.9, p < 0.001) followed by Blacks, and non-Black infants with CA >3 days and GA >35 weeks. ΔTSB was positive in Blacks, and in infants with CA <3 days, or with no phototherapy. ΔTSB was negative in non-Blacks, in infants with positive direct Coombs test (DC+) or those receiving phototherapy. Black race [beta (SE) = 1.3(0.33), p < 0.001] had positive, while CA [beta (SE) =-1.74 (0.36), p < 0.001], DC + status [beta (SE) =-0.72 (0.25), p = 0.004] and receipt of phototherapy [beta (SE) =-0.84 (0.21), p < 0.001] each had negative correlation with ΔTSB. ΔTSB for Blacks was >Whites, Hispanics and Asians.

CONCLUSION

SB is best predicted by TCB in Black infants with CA over 3 days and GA over 35 weeks. Variability in SB estimation by TCB is race, CA and immune mediated hemolysis specific.

Rate of rise of total serum bilirubin in very low birth weight preterm infants

BACKGROUND

To assess the postnatal rate of rise (ROR) of total serum bilirubin (TSB) in very low birth weight (VLBW) preterm infants, to determine risk factors associated with a rapid rise (>90th percentile), and to compare ROR and hour-specific TSB at postnatal 12-48 h with data of term infants retrieved from the literature.

METHODS

Retrospective analysis of 2430 routine TSB concentrations obtained between birth and initiation of phototherapy in 483 VLBW infants.

RESULTS

TSB increased by a median (interquartile range) ROR of 0.15 (0.11-0.19) mg/dL/h. The 50th percentile of TSB was below the 40th percentile of (near-)term counterparts at 12-48 h. TSB ROR correlated with the age at initiation (R_S = -0.687; p < 0.001) and the duration (R_S = 0.444; p < 0.001) of phototherapy. ROR >90th percentile (>0.25 mg/dL/h) was associated with lower gestational ages [27.2 (25.4-29.3) vs. 28.4 (26.4-30.4) weeks], lower birth weights [978 (665-1120) vs. 1045 (814-1300) g], and lower 5-min Apgar scores [7 (7-8) vs. 8 (7-9)].

CONCLUSION

ROR of TSB is an indicator for early and prolonged phototherapy. While hour-specific TSB and ROR at 12-48 h are lower than those reported for (near-)term infants, TSB appears to rise more rapidly in infants with low gestational age, low birth weight, and low 5-min Apgar score.

The accuracy of transcutaneous bilirubinometry in preterm infants

OBJECTIVE

To evaluate the correlation between total serum and transcutaneous bilirubin and to determine the reliability of transcutaneous bilirubinometry for screening and monitoring of neonatal jaundice among preterms.

STUDY DESIGN

Ninety nine infants with gestational ages ≤34 weeks were prospectively enrolled. Babies were classified into three groups as; 24-28, 29-31, and 32-34 weeks. Total serum bilirubin and simultaneous transcutaneous bilirubin were measured before the onset of phototheraphy, during and at 24 h after discontinuing phototherapy.

RESULTS

Total serum bilirubin significantly correlated with transcutaneous bilirubin in the whole cohort (r = 0.867, p < 0.001) and in each group before, during and after phototheraphy. Hypotension was the only variable which effects the difference between two methods at postnatal first day of life (p = 0.039).

CONCLUSION

Transcutaneous bilirubin levels were highly correlated with total serum bilirubin levels even in 24-28 GW babies. Transcutaneous bilirubin may be useful for screening and monitoring of jaundice in very preterm newborns.

Should transcutaneous bilirubin be measured in preterm infants receiving phototherapy? The relationship between transcutaneous and total serum bilirubin in preterm infants with and without phototherapy

Our objective was to analyze the relationship between transcutaneous bilirubin (TcB) measured on an unexposed area of skin and total serum bilirubin (TSB) in preterm infants before, during, and after phototherapy (PT). For this purpose paired TSB and TcB levels were measured daily during the first ten days after birth in preterm infants of less than 32 weeks’ gestation. TcB was measured with a Dräger Jaundice Meter JM-103 on the covered hipbone. Agreement between TSB and TcB levels was assessed before, during, and after PT. True negative and corresponding false negative percentages were calculated using different TcB cut-off levels. Data are presented as mean (±SD). We obtained 856 paired TcB and TSB levels in 109 preterm infants (66 boys, gestational age 29.4 ± 1.6 weeks and birth weight 1282 g ± 316 g). We found that the difference between TSB and TcB before PT was significantly lower, 44 (±36) μmol/L, than the difference during and after PT, 61 (±29) μmol/L and 63 (±25) μmol/L, respectively; P < 0.01. Blood sampling could be reduced by 42%, with 2% false negatives, when 50 μmol/L was added to the TcB level at 70% of the PT threshold. Our conclusion is that phototherapy enhances underestimation of TSB by TcB in preterms, even if measured on unexposed skin. The use of specific TcB cut-off levels substantially reduces the need for TSB measurements.

Transcutaneous bilirubinometer use and practices surrounding jaundice in 150 California newborn intensive care units

OBJECTIVES

Transcutaneous bilirubin measurements (TcBs) provide a noninvasive method for screening infants for hyperbilirubinemia and have been used extensively in term and late preterm newborns in well baby nurseries, offices, and outpatient clinics. Several studies have also demonstrated the utility of TcBs as a screening tool for infants > 28 weeks' gestation and their ability to reduce the need for blood sampling. The objectives of this study are to identify how often TcBs are used among California Newborn Intensive Care Units (NICUs) in preterm, late preterm and term infants, and other aspects of jaundice management.

METHODS

We conducted a survey on TcB use and practices relating to jaundice management in 150 California NICUs between April and October 2016.

RESULTS

TcB screening is routinely used in 28% (42/150) of NICUs. Only 7% (11/150) of NICUs use TcB in preterm infants < 28 weeks. Practice varied similarly across NICU levels of care. Among the subset of NICUs that responded to questions related to phototherapy and screening practices, prophylactic phototherapy was used in 38% (23/59) and 90% (55/61) screened for glucose-6-phosphate dehydrogenase deficiency based on race, ethnicity, and/or family history.

CONCLUSION(S)

Despite studies validating the accuracy of TcB in preterm infants > 28 weeks, only 28% of California NICUs routinely use TcB devices. TcB screening in infants < 28 weeks gestation is not widely used and no recommendation can be made in this regard until there is more experience with its application using a standardized protocol in these infants and on a large scale.

Comparison of Transcutaneous and Serum Bilirubin Measurements in Neonates 30 to 34 Weeks' Gestation Before, During, and After Phototherapy

BACKGROUND

The use of noninvasive, transcutaneous bilirubin monitoring (TcB) as a jaundice screen in full-term infants is well established; however, there is a paucity of research evaluating the use of TcB in premature infants.

PURPOSE

To compare agreement and consistency of transcutaneous and serum bilirubin measurements in a multiracial premature infant population ranging from 30 to 34(Equation is included in full-text article.)weeks' gestation before, during, and after phototherapy.

METHODS

Forty-five neonates, 30 to 34(Equation is included in full-text article.)weeks' gestation, were enrolled in this prospective, correlational study over a 12-month period. One set of paired transcutaneous and serum bilirubin measurements, per neonate, was obtained before phototherapy, during therapy, and after phototherapy. Exclusion criteria included neonates with positive direct coombs test or evidence of hemolytic disease, major congenital anomalies, hydrops fetalis, and those not expected to survive.

RESULTS

There was a strong, positive correlation between TcB and total serum monitoring (TSB) measurements obtained pretherapy (r = 0.797, P < .001). A moderate correlation was noted between TcB and TSB measurements obtained during therapy (r = 0.588, P < .001). A strong correlation was noted between TcB and TSB measurements obtained posttherapy (r = 0.869, P < .001). There were no significant differences between paired samples across time (F = 0.891, P = .41, partial η = 0.01). The TSB measurements were consistently lower than TcB pretherapy, during, and posttherapy.

IMPLICATIONS FOR PRACTICE

The TcB measurements provide a reliable estimation, generally within 2 to 3 mg/dL of TSB levels, in premature infants 30 to 34(Equation is included in full-text article.)weeks' gestation.

IMPLICATIONS FOR RESEARCH

Investigation of consumption of time and nursing personnel required to perform TcB testing, compared with TSB testing, is indicated. Cost analyses comparing TcB-driven screening protocols and interval TSB measurements, among premature infants, are indicated. As newer generations of TcB devices are approved for use, additional studies using mixed-race populations of premature infants will be necessary to continue to evaluate the reliability and validity of this screening tool within the everyday neonatal intensive care unit.

Transcutaneous Bilirubinometry in Jaundiced Neonates: A Randomized Controlled Trial

BACKGROUND

For evaluation of jaundiced neonates, serum bilirubin (SB) or transcutaneous bilirubinometry (TcB) is used. Few data are available on the quantitative reduction of blood sampling by using TcB.

METHODS

We conducted a randomized controlled trial in hospitalized jaundiced neonates ≥32 weeks' gestational age. In the intervention group, TcB was used and in the control group the decision to obtain a blood sample for SB was based on visual and clinical assessment. Outcome measure was the number of blood samples before phototherapy. When TcB was <50 µmol/L below the threshold for phototherapy, SB was obtained. The decision to start treatment was always based on an SB value.

RESULTS

A total of 430 were randomized and included in the intention-to-treat analysis: 213 in the TcB group and 217 in the control group. In the TcB group, 104 (48.4%) had at least 1 blood sample taken for SB, versus 172 (79.3%) in the control group (difference 30.5%, 95% confidence interval 21.5-38.7, P < .001). The number of blood draws was significantly reduced by 38.5% (0.9 ± 1.1 vs 1.3 ± 1.0, difference -0.5, 95% confidence interval -0.7 to -0.3, P < .001). Peak of bilirubin value, indications for phototherapy, or exchange transfusion and hospitalization length were not different between groups.

CONCLUSIONS

The use of TcB in jaundiced neonates is feasible and safe, resulting in a reduction of more than one-third in blood draws.