Transcutaneous bilirubin measurement during phototherapy in term neonates

The use of a simple and affordable skin patch for measurement of transcutaneous bilirubin levels in neonates during phototherapy

Background

Transcutaneous bilirubin (TcB) measurements during and after phototherapy for hyperbilirubinemia must be performed on unexposed skin. There are commercially made skin patches for this purpose, but they are relatively unavailable in low-resource settings. We devised a simple cotton patch and tested its use for TcB during phototherapy.

Methods

Measurements were taken in healthy neonates born at a gestational age of ≥35 weeks who were undergoing phototherapy for hyperbilirubinemia in western India before, 12 h after the start, and 12 h after the end of phototherapy. Total serum bilirubin (TSB) was measured using the diazo method in a clinical laboratory. TcB measurements were performed using a Dräger Jaundice Meter JM-105 placed over the sternum on two skin areas that were protected during and after treatment by a commercial (Philips BilEclipse) or self-made patch comprised of cotton gauze and wool.

Results

In total, 47 neonates were included in our study. Before phototherapy, TSB and TcB values had a strong correlation (Pearson, r = 0.88), with a mean difference of -1.35 mg/dl. Correlations with TSB were good and equivalent for TcB values measured on skin covered by the commercial and self-made patches during (0.78 and 0.70, respectively) and after (0.57 and 0.58, respectively) phototherapy. TcB values measured on skin covered by the two patches correlated well both during and after phototherapy, with r = 0.82 and 0.90, respectively, and mean (95% confidence interval) differences of -1.21 and -0.32 mg/dl, respectively.

Conclusions

Reliable TcB measurements taken during and after phototherapy can be achieved on skin covered with a simple and affordable cotton skin patch.

Transcutaneous bilirubin reliability during and after phototherapy depending on skin color

Measurement of transcutaneous bilirubin (TcB) is a non-invasive, widely used technique to estimate serum bilirubin (SB). However, its reliability in multiethnic populations during and after phototherapy is still controversial even in covered skin. The aim of this study was to determine the reliability of TcB in covered (cTcB) and exposed (eTcB) skin during and after phototherapy in a multiethnic population of term and preterm neonates according to Neomar's neonatal skin color scale. Prospective, observational study comparing SB and TcB. We determined SB when clinically indicated and, at the same time, measured cTcB under a photo-opaque patch and eTcB next to it with a jaundice meter (Dräger JM-105TM). All dyads TcB-SB were compared, both globally and according to skin color. We obtained data from 200 newborns (color1: 44, color2: 111, color3: 41, color4: 4) and compared 296 dyads TcB/SB. Correlation between cTcB and SB is strong during (0.74-0.83) and after (0.79-0.88) phototherapy, both globally and by color group. The SB-cTcB bias depends on gestational age during phototherapy and on skin color following phototherapy. The correlation between eTcB and SB during phototherapy is not strong (0.54), but becomes so 12 h after discontinuing phototherapy (0.78).  Conclusions: Our study supports the reliability of cTcB to assess SB during and after phototherapy, with differences among skin tones after the treatment. The use of cTcB and Neomar's scale during and mainly after phototherapy may help reduce the number of blood samples required. What is Known: • Controversies exist on the reliability of jaundice meters during and after phototherapy in covered skin. 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 covered skin in a multiethnic population depending on skin color based on our own validated neonatal skin color scale during and after phototherapy.

Transcutaneous Bilirubin Accuracy Before, During, and After Phototherapy: A Meta-Analysis

CONTEXT

Transcutaneous bilirubinometry (TcB) is used as a valid screening to identify neonates requiring measurement of total serum bilirubin (TSB) before phototherapy. Its use during and after phototherapy is not advised yet because of unknown reliability.

OBJECTIVES

To determine the agreement of TcB and TSB measurements before, during, and after phototherapy.

DATA SOURCES

PubMed Medline, Cochrane Library, and references of eligible studies were searched.

STUDY SELECTION

Prospective and retrospective cohort and cross-sectional studies reporting Bland-Altman statistics of paired TcB and TSB measurements in term and preterm newborns.

DATA EXTRACTION

Meta-analysis was performed using the Mantel-Haenszel weighted approach. The agreement between TcB and TSB in μmol/L was described by pooled mean differences (MDs) and limits of agreement (LoA).

RESULTS

Fifty-four studies were included. The pooled MD before phototherapy is 2.5 μmol/L (LoA -38.3 to 43.3). The pooled MD during phototherapy is -0.3 μmol/L (LoA -34.8 to 34.2) on covered skin and -28.6 μmol/L (LoA -105.7 to 48.5) on uncovered skin. The pooled MD after phototherapy is -34.3 μmol/L (LoA -86.7 to 18.1) on covered skin and -21.1 μmol/L (LoA -88.6 to 46.4) on uncovered skin. Subgroup analysis revealed the best agreement at the forehead. We did not find any difference in agreement between term and preterm neonates.

LIMITATIONS

Language restriction.

CONCLUSIONS

TcB measurements before and during phototherapy on covered skin show good agreement compared with TSB in term and preterm newborns. More studies are needed to evaluate the accuracy after phototherapy.

The Impact of Phototherapy on the Accuracy of Transcutaneous Bilirubin Measurements in Neonates: Optimal Measurement Site and Timing

Transcutaneous bilirubinometer devices are widely applied to assess neonatal hyperbilirubinemia. However, the optimal skin site and timing of transcutaneous bilirubin (TCB) measurements for the strongest correlation with total serum bilirubin (TSB) levels after phototherapy are still unclear. We conducted a retrospective observational study evaluating the correlation of TCB and TSB levels in neonates postphototherapy. The TCB measurements on the forehead and mid-sternum at 0 and 30 min postphototherapy were assessed by using a JM-103 bilirubinometer. Paired TCB and TSB measurements were assessed by Pearson correlation and Bland–Altman plots. We analyzed 40 neonates with 96 TSB and 384 TCB measurements. The TSB level correlated moderately with the forehead TCB level at 30 min postphototherapy (r = 0.65) and less strongly with the midsternum TCB level at 0 min postphototherapy (r = 0.52). The forehead at 30 min after cessation of phototherapy was the best time point and location of TCB measurement for the assessment of neonatal jaundice status. The reliability of TCB measurements varied across skin sites and durations after phototherapy. The effectiveness of TCB measurement to assess neonatal hyperbilirubinemia is much better on covered skin areas (foreheads) 30 min postphototherapy. The appropriate application of transcutaneous bilirubinometers could aid in clinical practice and avoid unnecessary management.

Accuracy of Transcutaneous Bilirubin Versus Serum Bilirubin Measurement in Preterm Infants Receiving Phototherapy: A Systematic Review

BACKGROUND

Jaundice is a common condition among preterm infants in the neonatal intensive care unit (NICU). Total serum bilirubin (TSB) offers a gold standard tool for measurement, but blood sampling can be costly, time-consuming, and not without risks of infection and pain. Transcutaneous bilimeter (TcB) allows for noninvasive assessment of bilirubin. However, due to questions of accuracy the use of the TcB in preterm infants receiving phototherapy has not been widely adapted in the NICU.

PURPOSE

To systematically review studies that measure TcB versus TSB bilirubin in preterm infants who are receiving phototherapy.

METHODS

A systematic electronic search of databases (CINAHL, EMBASE, Cochrane, Medline, PubMed) was completed for English language publications. No date limitation was placed on the search. Inclusion criteria were based on preterm infants that were in the NICU receiving or had recently received phototherapy.

RESULTS

Nine studies of different quantitative study designs were reviewed. A good to strong correlation between TcB and TSB in preterm infants receiving phototherapy was demonstrated. There was a stronger correlation found in studies that examined TcB in unexposed skin areas during phototherapy.

IMPLICATIONS FOR PRACTICE

TcB may allow for a reduction in blood sampling, which would reduce painful procedures, reduce the risk of infection and anemia resulting from repeated blood sampling. It also acts as a more time and cost-efficient measurement tool.

IMPLICATIONS FOR RESEARCH

Larger scaled quantitative studies on the accuracy of TcB in preterm infants receiving phototherapy are needed to provide more evidence-based data and guide clinical practice on this topic.

Accuracy of transcutaneous bilirubin on covered skin in preterm and term newborns receiving phototherapy using a JM-105 bilirubinometer

OBJECTIVE

Determine the suitability of transcutaneous bilirubin (TCB) as a tool to assess the effectiveness of phototherapy on patched skin.

STUDY DESIGN

A prospective observational study was conducted. We covered a fragment of skin (sternum) with a photo-opaque patch. Several simultaneous TCB and TSB measurements were performed with the JM-105 bilirubinometer. Bland and Altman test evaluated the agreement between bilirubin levels.

RESULT

A total of 217 patients were studied, 48.8% were preterm. The mean difference between TSB and TCB before the start of treatment was 1.07 mg/dL. During phototherapy, differences on covered skin were 0.52, 0.27, and 0.39 mg/dL at 24, 48, and 72 h of therapy respectively. The best correlation was observed at 48 h in preterm infants.

CONCLUSION

The measurement of TCB on patched skin (PTCB) is useful for monitoring the response to phototherapy in term and preterm infants. We use a patch with a removable flap that eases successive measures without disturbing the patients.

Comparison of transcutaneous and serum bilirubin before, under, and after phototherapy in term and late-preterm infants

This study aimed to determine the correlation of transcutaneous bilirubin (TcB) with total serum bilirubin (TSB) in infants receiving phototherapy and the accuracy of TcB for deciding the time to discontinue phototherapy. Paired TcB and TSB levels were assessed in 52 term and 56 late-preterm infants receiving phototherapy. TcB was measured in the unexposed skin of the middle forehead using a noninvasive bilirubin analyzer, BiliChek. TSB was measured every morning, and TcB was measured 2 hours after TSB measurements. Bland-Altman plots, linear regression, multivariate pair wise correlation, and receiver operating characteristic curve (ROC) analyses were performed. Bland-Altman plots before, under, and 24 hours after phototherapy in term and late-preterm infants revealed that TcB and TSB have higher consistency. TcB and TSB showed positive linear correlation before, under, and after phototherapy in both infant groups. In the multivariate pair wise correlations, differences between TcB and TSB were negatively correlated with phototherapy duration in term (correlation coefficient = -0.233, P value = .001) and late-preterm (correlation coefficient = -0.198, P value = .002) infants. Cutoff levels of TcB for discontinuing phototherapy based on the ROC analysis were 13.8 (sensitivity of 90%, specificity of 84%, area under the curve [AUC] 0.94) and 11.8 mg/dL (sensitivity of 84%, specificity of 88%, AUC 0.92) in term and late-preterm infants, respectively. TcB and TSB before, under, and after phototherapy in both term and late-preterm infants showed good correlation and higher consistency with jaundice. To reduce repetitive blood sampling for TSB, TcB measurement may be a reliable method for term and late-preterm infants undergoing phototherapy.

Transcutaneous Bilirubin Measurements Can Be Used to Measure Bilirubin Levels during Phototherapy

Objective

To determine whether transcutaneous bilirubin measurements (TcB) before and during phototherapy taken from covered skin during phototherapy correlate with total serum bilirubin (TSB) levels.

Study Design

In this prospective observational study, healthy term newborns who required TSB measurements were included. TcB measurements were taken from the forehead before starting and during phototherapy using the BiliChek device. Before starting phototherapy, part of the forehead was covered. Blood for TSB measurement was collected within 5 minutes of TcB measurements. Correlations and mean differences between TcB and TSB before and during phototherapy were calculated.

Result

Paired TSB and TcB measurements before and during phototherapy in 151 newborns were performed. The mean gestational age was 38.8 weeks and birth weight was 3.1 kg; 53% were male. Before starting phototherapy, TSB and TcB were 183.8 ± 41.6 and 190.5 ± 43 μmol/l, respectively. During phototherapy, TSB and TcB were 191.8 ± 39.4 and 187.8 ± 45.3 μmol/l, respectively. Linear regression analysis showed a significant correlation between TcB and TSB before starting phototherapy and during phototherapy (r: 0.85; p < 0.001 and r: 80.0; p < 0.001), respectively. Before starting phototherapy, the mean difference between TSB and TcB was 6.2 ± 23.2 μmol/l, with a 95% CI of -39.3 to 51.7 μmol. During phototherapy, the mean difference was -2.8 ± 23.5 μmol/l, with a 95% CI of -48.9 to 43.3 μmol/l.

Conclusion

TcB measurements from covered skin in jaundiced term infants during phototherapy correlate with TSB and can be used to monitor bilirubin levels during phototherapy.