A randomized, triple-blind, placebo-controlled trial of prophylactic oral phenobarbital to reduce the need for phototherapy in G6PD-deficient neonates

Use of reflective materials during phototherapy for newborn infants with unconjugated hyperbilirubinaemia

BACKGROUND

Phototherapy is a well-established effective therapy for treating babies with significant neonatal jaundice. Studies have shown that increasing light intensity will increase its efficiency. A potentially inexpensive and easy way of increasing the intensity of light on the body of the infant may be to hang reflective materials from the sides of phototherapy units.

OBJECTIVES

To assess the effects of reflective materials in combination with phototherapy compared with phototherapy alone for unconjugated hyperbilirubinaemia in neonates.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 11), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index of Nursing and Allied Health Literature (CINAHL), on 1 November 2019. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials if the participants, who were term or preterm infants, received phototherapy with curtains made of reflective materials of any type in the treatment arm, and if those in the comparison arm received similar phototherapy without curtains or other intensified phototherapy, such as a double bank of lights.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Of 15 studies identified, we included 12 (1288 babies) in the review - 11 comparing phototherapy with reflective materials and phototherapy alone, and one comparing a single phototherapy light bank with reflective materials with double phototherapy. All reflective materials consisted of curtains on three or four sides of the cot and were made of white plastic (five studies), white linen (two studies), or aluminium (three studies); materials were not specified in two studies. Only 11 studies (10 comparing reflective materials versus none and one comparing reflective curtains and a single bank of lights with a double (above and below) phototherapy unit) provided sufficient data to be included in the meta-analysis. Two excluded studies used the reflective materials in a way that did not meet our inclusion criteria, and we excluded one study because it compared four different phototherapy interventions not including reflective materials. The risk of bias of included studies was generally low, but all studies had high risk of performance bias due to lack of blinding of the intervention. Three studies (281 participants) reported a decline in serum bilirubin (SB) (μmol/L) at four to eight hours (mean difference (MD) -14.61, 95% confidence interval (CI) -19.80 to -9.42; I² = 57%; moderate-certainty evidence). Nine studies (893 participants) reported a decline in SB over 24 hours and showed a faster decline in SB in the intervention group, but heterogeneity (I² = 97%) was too substantial to permit a meaningful estimate of the actual effect size (very low-certainty evidence). Subgroup analysis by type of reflective material used did not explain the heterogeneity. Exchange transfusion was reported by two studies; both reported none in either group. Four studies (466 participants) reported the mean duration of phototherapy, and in each of these studies, it was reduced in the intervention group but there was substantial heterogeneity (I² = 88%), precluding meaningful meta-analysis of data. The only two studies that reported the mean duration of hospital stay in hours showed a meaningful reduction (MD -41.08, 95% CI -45.92 to -36.25; I² = 0; moderate-certainty evidence). No studies reported costs of the intervention, parental or medical staff satisfaction, breastfeeding outcomes, or neurodevelopmental follow-up. The only study that compared use of curtains with double phototherapy reported similar results for both groups. Studies that monitored adverse events did not report increased adverse events related to the use of curtains, including acute life-threatening events, but other rarer side effects could not be excluded.

AUTHORS' CONCLUSIONS

Moderate-certainty evidence shows that the use of reflective curtains during phototherapy may result in greater decline in SB. Very low-certainty evidence suggests that the duration of phototherapy is reduced, and moderate-certainty evidence shows that the duration of hospital stay is also reduced. Available evidence does not show any increase in adverse events, but further studies are needed.

Reductive effect of ursodeoxycholic acid on bilirubin levels in neonates on phototherapy

Background

Phototherapy is paramount in the management of high total serum bilirubin (TSB). Whether its effectiveness can be improved with ursodeoxycholic acid (UDCA) has not been evaluated among newborns of African descent.

Methods

A double-blind-controlled study was used to evaluate the effect of UDCA on the management of high TSB in neonates. Recruited neonates were categorized into the experimental group (given UDCA plus phototherapy) and the control group (phototherapy and plain syrup), and their TSB and conjugated bilirubin levels were measured. The data were analyzed using SPSS version 20. Statistical significance was set at a p-value of <0.05.

Results

The mean (SD) percentage reductions in TSB after 24 hrs were 40.73% (18.1) and 10.21% (7.1) in the experimental and control groups, respectively, and the difference was statistically significant (p=0.001). The mean (SD) durations on therapy were 3.0 days (0.58) in the experimental group and 5.5 days (1.35) in the control group (p=0.001).

Conclusions

Phototherapy is still effective in the management of neonatal hyperbilirubinemia, but inclusion of UDCA accentuates the reductive effect of phototherapy on the TSB in neonates, reducing the duration of treatment and in-patient care.

Developmental, Genetic, Dietary, and Xenobiotic Influences on Neonatal Hyperbilirubinemia

Hyperbilirubinemia, caused by the accumulation of unconjugated bilirubin, is one of the most common clinical diagnoses in both premature and term newborns. Owing to the fact that bilirubin is metabolized solely through glucuronidation by UDP-glucuronosyltransferase (UGT) 1A1, it is now known that immaturity of UGT1A1, in combination with the overproduction of bilirubin during the developmental stage, acts as a bottleneck to bilirubin elimination and predisposes the infant to high total serum bilirubin levels. Although neonatal jaundice is mostly benign, excessively high levels of serum bilirubin in a small percentage of newborns can cause bilirubin-induced neurologic dysfunction, potentially leading to permanent brain damage, a condition known as kernicterus Although a large portion of hyperbilirubinemia cases in newborns are associated with hemolytic diseases, we emphasize here the impaired ability of UGT1A1 to eliminate bilirubin that contributes to hyperbilirubinemia-induced neurotoxicity in the developmental stage. As a series of hereditary UGT1A1 mutations have been identified that are associated with UGT1A1 deficiency, new evidence has verified that delayed expression of UGT1A1 during the early stages of neonatal development is a tightly controlled event involving coordinated intrahepatic and extrahepatic regulation. This review recapitulates the progress that has been made in recent years in understanding the causes and physiopathology of severe hyperbilirubinemia, investigating molecular mechanisms underlying bilirubin-induced encephalopathy, and searching for potential therapies for treating pathologic hyperbilirubinemia. Several animal models have been developed to make it possible to examine bilirubin-induced neurotoxicity from multiple directions. Moreover, environmental factors that may alleviate or worsen the condition of hyperbilirubinemia are discussed.

Phenobarbitone in Rh hemolytic disease of the newborn: a randomized double-blinded placebo-controlled trial

OBJECTIVE

To evaluate the efficacy of prophylactic oral phenobarbitone (PB) in neonates with Rh hemolytic disease of the newborn.

STUDY DESIGN

In this double-blind randomized trial conducted in a tertiary care unit, we randomly allocated neonates with Rh hemolytic disease of the newborn born at or after 32 weeks' gestation to PB (10 mg/kg/day on day 1 followed by 5 mg/kg/day on days 2-5) (n = 23) or oral glucose (n = 21). The primary outcome was the duration of phototherapy.

RESULTS

Baseline variables were comparable. There was no difference in the median duration of phototherapy [54 (range: 0-180) vs. 35 h (0-127); p = 0.39] and in the incidences of failure of phototherapy or significant rebounds of serum bilirubin. However, the proportion of infants with cholestasis was significantly lower in the PB group (0 vs. 19%; p = 0.04).

CONCLUSIONS

PB does not reduce duration of phototherapy or its episodes. Its potential to reduce cholestasis needs validation in larger studies.

Pregnane-x-receptor controls hepatic glucuronidation during pregnancy and neonatal development in humanized UGT1 mice

In humanized UDP glucuronosyltransferase-1 (hUGT1) mice that express the entire UGT1 locus, the maternal hepatic UGT1A genes are dramatically induced 12-14 days after conception. Steroid induction of the UGT1A1 gene indicates that xenobiotic sensors, such as the pregnane X receptor (PXR) and constitutive androstane receptor (CAR), may underlie the induction process. In contrast, neonatal hUGT1 mice display severe hyperbilirubinemia, with limited expression of the UGT1A genes. This study identifies PXR as both a positive and negative regulator of the UGT1A1 gene. Pregnancy hormones, in particular the glucocorticoids, target PXR as a positive regulator of human glucuronidation. Employing reverse genetics, where PXR has been genetically deleted, hUGT1/Pxr(-/-) mice show limited induction of the liver UGT1A genes during pregnancy, whereas the exact opposite occurs in newborn mice. Neonatal hUGT1 mice show delayed expression of hepatic UGT1A1 and are severely hyperbilirubinemic. However, in hUGT1/Pxr(-/-) mice, hyperbilirubinemia is greatly reduced due to induction of hepatic UGT1A1. Thus, PXR serves to repress UGT1A1 gene expression during development. Transcriptional silencing of the UGT1A1 gene was relieved in neonatal hUGT1 hepatocytes through interruption of PXR by small interfering RNA.

CONCLUSION

PXR is a key regulator of pregnancy induced glucuronidation capacity in addition to modulating the severity of neonatal jaundice.

The side effects of phototherapy for neonatal jaundice: what do we know? What should we do?

Neonatal phototherapy (NNPT), a noninvasive, easily available therapy, has been widely used for the treatment of neonatal jaundice for more than half a century. Its efficiency in decreasing plasma bilirubin concentration is well documented, and NNPT leads to greatly reduced exchange transfusion rates for neonates with hyperbilirubinemia. It is generally accepted that the side effects of NNPT are not serious and seem to be well controlled. This review will focus on these possible side effects as well as the approaches to minimize them.

Blood exchange transfusion for infants with severe neonatal hyperbilirubinemia

Blood exchange transfusion has become a rare event in most developed countries. As a result, many pediatricians may not have performed or even seen one. However, it remains a frequent emergency rescue procedure for severe neonatal hyperbilirubinemia in many underdeveloped regions of the world. Conventionally, exchange transfusion has been performed via a central umbilical venous catheter by pull-push cycle method and recently peripheral artery/peripheral vein has emerged as an alternative, isovolumetric route. Continuous arterio-venous exchange is possibly more effective though its automation has not been successful. Concerns for procedural and operator related adverse events have been raised in the context of declining indications. A required continued expertise for this life-saving intervention, in the face of rare but critical hyperbilirubinemia and/or unrecognized hemolytic diseases, deserves adaptation of newer technologies to make neonatal exchange transfusion a safer and more effective procedure. Technological innovations and simulation technologies are urgently needed.