Glucagon for Neonatal Hypoglycaemia: Systematic Review and Meta-Analysis

Neonatal hypoglycaemia

Low blood concentrations of glucose (hypoglycaemia) soon after birth are common because of the delayed metabolic transition from maternal to endogenous neonatal sources of glucose. Because glucose is the main energy source for the brain, severe hypoglycaemia can cause neuroglycopenia (inadequate supply of glucose to the brain) and, if severe, permanent brain injury. Routine screening of infants at risk and treatment when hypoglycaemia is detected are therefore widely recommended. Robust evidence to support most aspects of management is lacking, however, including the appropriate threshold for diagnosis and optimal monitoring. Treatment is usually initially more feeding, with buccal dextrose gel, followed by intravenous dextrose. In infants at risk, developmental outcomes after mild hypoglycaemia seem to be worse than in those who do not develop hypoglycaemia, but the reasons for these observations are uncertain. Here, the current understanding of the pathophysiology of neonatal hypoglycaemia and recent evidence regarding its diagnosis, management, and outcomes are reviewed. Recommendations are made for further research priorities.

Variability in Diagnosis and Management of Hypoglycemia in Neonatal Intensive Care Unit

OBJECTIVE

 Hypoglycemia, the most common metabolic derangement in the newborn period remains a contentious issue, not only due to various numerical definitions, but also due to limited therapeutical options which either lack evidence to support their efficacy or are increasingly recognized to lead to adverse reactions in this population. This study aimed to investigate neonatologists' current attitudes in diagnosing and managing transient and persistent hypoglycemia in newborns admitted to the Neonatal Intensive Care Unit (NICU).

METHODS

 A web-based electronic survey which included 34 questions and a clinical vignette was sent to U.S. neonatologists.

RESULTS

 There were 246 survey responses with most respondents using local protocols to manage this condition. The median glucose value used as the numerical definition of hypoglycemia in first 48 hours of life (HOL) for symptomatic and asymptomatic term infants and preterm infants was 45 mg/dL (2.5 mmol/L; 25-60 mg/dL; 1.4-3.3 mmol/L), while after 48 HOL the median value was 50 mg/dL (2.8 mmol/L; 30-70 mg/dL; 1.7-3.9 mmol/L). There were various approaches used to manage transient and persistent hypoglycemia that included dextrose gel, increasing caloric content of the feeds using milk fortifiers, using continuous feedings, formula or complex carbohydrates, and use of various medications such as diazoxide, glucocorticoids, and glucagon.

CONCLUSION

 There is still large variability in current practices related to hypoglycemia. Further research is needed not only to provide evidence to support the values used as a numerical definition for hypoglycemia, but also on the efficacy of current strategies used to manage this condition.

KEY POINTS

· Numerical definition of glucose remains variable.. · Strategies managing transient and persistent hypoglycemia are diverse.. · There is a need for further research to investigate efficacy of various treatment options..

Delivery room glucose to reduce the risk of admission hypoglycemia in preterm infants: a systematic literature review

AIMS

In order to mitigate early hypoglycemia in preterm infants, some clinicians have recently explored interventions such as delivery room commencement of dextrose infusions or delivery room administration of buccal dextrose gel. This review aimed to systematically investigate the literature regarding the provision of delivery room (prior to admission) parenteral glucose as a method to reduce the risk of initial hypoglycemia (measured at the time of NICU admission blood testing) in preterm infants.

MATERIALS AND METHODS

Using PRISMA guidelines a literature search (May 2022) was conducted using PubMed, Embase, Scopus, Cochrane Library, OpenGrey, and Prospero databases. The clinicaltrials.gov database was searched for possible completed/ongoing clinical trials. Studies that included moderate preterm (≤33⁺⁶ weeks) or younger birth gestations or very low birth weight (or smaller) infants, and that administered parenteral glucose in the delivery room were included. The literature was appraised via data extraction, narrative synthesis, and critical review of the study data.

RESULTS

A total of five studies (published 2014-2022) were eligible for inclusion (three before-after "quasi-experimental" studies, one retrospective cohort study, and one case-control study). Most included studies used intravenous dextrose as the intervention. Individual study effects (odds ratios) favored the intervention in all included studies. It was felt that the low number of studies, the variability in study design, and the nonadjustment for confounding co-interventions (co-exposures) precluded a meta-analysis. Quality assessment of the studies revealed a spectrum of bias from low to high risk, however, most studies had moderate to high risk of bias, and their direction of bias favored the intervention.

CONCLUSIONS

This extensive search and systematic appraisal of the literature indicates that there exists few studies (these are low grade and at moderate to high risk of bias) for the interventions of either intravenous or buccal dextrose given in the delivery room. It is not clear if these interventions impact on rates of early (NICU admission) hypoglycemia in these preterm infants. Obtaining intravenous access in the delivery room is not guaranteed and can be difficult in these small infants. Future research should consider various routes for commencing delivery room glucose in these preterm infants and should take the form of randomized controlled trials.

Delayed-Onset Transient Hyperinsulinism in Infants with Very Low and Extremely Low Birth Weights: A Cohort Study

We describe 16 infants born preterm with birth weights <1500 g and transient hyperinsulinism. The onset of hyperinsulinism was delayed and often coincident with clinical stabilization. We hypothesize that postnatal stress caused by prematurity and associated problems may contribute to development of delayed-onset transient hyperinsulinism.

Protecting against brain damage by improving treatment in neonates with hypoglycaemia: ProBrain-D-a study protocol of a prospective longitudinal study

INTRODUCTION

Although neonatal hypoglycaemia is the most common metabolic problem in neonates, there is no standard guideline for screening. Additionally, treatment of neonatal hypoglycaemia and glucose administration thresholds are discussed controversially. Severe hypoglycaemia can lead to brain damage, but data on the effects of mild hypoglycaemia on neurological development are limited. To our knowledge, this is the first prospective longitudinal cohort study to analyse if the implementation of a new diagnosis and treatment standard for neonatal hypoglycaemia may improve the outcome of neonates at risk for hypoglycaemia, especially concerning neurodevelopment. Furthermore, the acceptance and feasibility of the standard among different professional groups and parents are analysed.

METHODS AND ANALYSIS

After implementation of a structured standard operating procedure (SOP), detailing preventive measures, blood glucose screening and neonatal hypoglycaemia treatment in a tertiary care hospital, 678 neonates ≥35+0 weeks of gestation will be recruited in a monocentric prospective cohort study. For comparison, 139 children born before the implementation of this new SOP, who had risk factors for neonatal hypoglycaemia or qualified for blood glucose measurements are recruited (retrospective cohort). For the primary end point, comparative analyses between and within the prospective and retrospective cohorts will be performed regarding the neurological outcome at 2-2.5 years of age in Bayley Scales of Infant Development. Furthermore, comprehensive clinical data and data on nutrition and developmental milestones are assessed at different time points (6 weeks, 6, 12, 18 and 24 months) in the prospective cohort. Acceptance and feasibility of the new standard are assessed using questionnaires.

ETHICS AND DISSEMINATION

The study has been approved by the Ethics Committee of the Medical Faculty of the Heinrich-Heine-University Düsseldorf (20201162). The results of this study will be disseminated through peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

DRKS00024086.

Application of the screening test principles to screening for neonatal hypoglycemia

Severe and prolonged neonatal hypoglycemia can cause brain injury, while the long-term consequences of mild or transitional hypoglycemia are uncertain. As neonatal hypoglycemia is often asymptomatic it is routine practice to screen infants considered at risk, including infants of mothers with diabetes and those born preterm, small or large, with serial blood tests over the first 12-24 h after birth. However, to prevent brain injury, the gold standard would be to determine if an infant has neuroglycopenia, for which currently there is not a diagnostic test. Therefore, screening of infants at risk for neonatal hypoglycemia with blood glucose monitoring does not meet several screening test principles. Specifically, the long-term neurodevelopmental outcomes of transient neonatal hypoglycemia are not well understood and there is no direct evidence from randomized controlled trials that treatment of hypoglycemia improves long-term neurodevelopmental outcomes. There have been no studies that have compared the long-term neurodevelopmental outcomes of at-risk infants screened for neonatal hypoglycemia and those not screened. However, screening infants at risk of hypoglycemia and treating those with hypoglycaemic episodes to maintain the blood glucose concentrations ≥2.6 mmol/L appears to preserve cognitive function compared to those without episodes. This narrative review explores the evidence for screening for neonatal hypoglycemia, the effectiveness of blood glucose screening as a screening test and recommend future research areas to improve screening for neonatal hypoglycemia. Screening babies at-risk of neonatal hypoglycemia continues to be necessary, but as over a quarter of all infants may be screened for neonatal hypoglycemia, further research is urgently needed to determine the optimal method of screening and which infants would benefit from screening and treatment.