Glucagon for hypoglycaemia in infants small for gestational age

Metabolic acidosis during continuous glucagon therapy for neonatal hypoglycemia

Objectives

Refractory neonatal hypoglycemia may be treated with glucagon infusions, which have been associated with thrombocytopenia and hyponatremia. After anecdotally noting metabolic acidosis during glucagon therapy in our hospital, an outcome not previously reported in the literature, we aimed to quantify occurrence of metabolic acidosis (base excess >-6) as well as thrombocytopenia and hyponatremia during treatment with glucagon.

Methods

We performed a single-centre retrospective case series. Descriptive statistics were used and subgroups compared with Chi-Square, Fisher's Exact Test, and Mann-Whitney U testing.

Results

Sixty-two infants (mean birth gestational age 37.2 weeks, 64.5% male) were treated with continuous glucagon infusions for median 10 days during the study period. 41.2% were preterm, 21.0% were small for gestational age, and 30.6% were infants of diabetic mothers. Metabolic acidosis was seen in 59.6% and was more common in infants who were not born to diabetic mothers (75% versus 24% in infants of diabetic mothers, P<0.001). Infants with versus without metabolic acidosis had lower birth weights (median 2,743 g versus 3,854 g, P<0.01) and were treated with higher doses of glucagon (0.02 versus 0.01 mg/kg/h, P<0.01) for a longer duration (12.4 versus 5.9 days, P<0.01). Thrombocytopenia was diagnosed in 51.9% of patients.

Conclusions

In addition to thrombocytopenia, metabolic acidosis of unclear etiology appears to be very common with glucagon infusions for neonatal hypoglycemia, especially in lower birth weight infants or those born to mothers without diabetes. Further research is needed to elucidate causation and potential mechanisms.

Glucagon for Neonatal Hypoglycaemia: Systematic Review and Meta-Analysis

INTRODUCTION

Glucagon is often used in neonatal hypoglycaemia, but its effects have not been systematically assessed. We undertook a systematic review to determine the efficacy and safety of glucagon treatment for neonatal hypoglycaemia.

METHODS

We searched MEDLINE, CINAHL, EMBASE, and CENTRAL from inception until May 2021. We included studies that reported one or more prespecified outcomes and compared glucagon with placebo or no glucagon. Studies were excluded if the majority (>70%) of participants were >1 month of age. Two authors independently extracted data. We used ROB-2/modified ROBINS-I to assess risk of bias, GRADE for certainty of evidence, and RevMan for meta-analysis.

RESULTS

100 studies were screened, 37 reviewed in full, and seven single-arm non-randomised intervention studies, involving 348 infants, were included (no trials). Data were insufficient to undertake meta-analysis of the critical outcomes (time to blood glucose normalization, recurrent hypoglycaemia, neurocognitive impairment). In 3 studies, ≥80% of neonates achieved normoglycaemia within 4 h of glucagon administration. However, recurrent hypoglycaemia was common (up to 55%). Glucagon increased blood glucose concentration at 1-2 h by 2.3 mmol/L (95% CI 2.1, 2.5) (low certainty evidence, 6 studies, N = 323). There were few data for other important clinical outcomes.

CONCLUSION

There is a paucity of evidence about the efficacy and safety of glucagon for treatment of neonatal hypoglycaemia. Low certainty evidence suggests that glucagon may increase blood glucose by ∼2.3 mmol/L but recurrent hypoglycaemia appears common. High-quality, randomized controlled trials are required to determine the role of glucagon in managing neonatal hypoglycaemia.

A comparison of the glycemic effects of glucagon using two dose ranges in neonates and infants with hypoglycemia

INTRODUCTION

Consensus regarding optimal glucagon dosing for management or diagnosis of neonatal/infant hypoglycemia has not been established.

OBJECTIVE

To investigate glycemic effects of glucagon dosed ≤0.2 mg/kg (Gn_low) vs. >0.2 mg/kg (Gn_high) in neonatal/infant hypoglycemia.

STUDY DESIGN

Retrospective, observational, cohort study.

RESULTS

Glucagon administration at any dose resulted in 75/77 (97.4%) samples meeting criteria for normoglycemia (plasma glucose >60 mg/dL), and plasma glucose increases of >30 mg/dL occurred in 74.2% vs. 63% (NS) of samples in the Gn_low and Gn_high groups, respectively. Despite equivalent glucagon dosing, there was a trend toward smaller (<2500 g) patients achieving post-glucagon plasma glucose increases of >30 mg/dL less often than their bigger (≥2500 g) counterparts (60% vs. 74.1%, NS).

CONCLUSIONS

Glucagon is highly effective in raising plasma glucose levels in neonatal/infant hypoglycemia. No differences in glycemic effects were noted between either dosing regimen. However, glycemic effects may be diminished in lower weight patients.

The screening and management of newborns at risk for low blood glucose

Hypoglycemia in the first hours to days after birth remains one of the most common conditions facing practitioners across Canada who care for newborns. Many cases represent normal physiologic transition to extrauterine life, but another group experiences hypoglycemia of longer duration. This statement addresses key issues for providers of neonatal care, including the definition of hypoglycemia, risk factors, screening protocols, blood glucose levels requiring intervention, and managing care for this condition. Screening, monitoring, and intervention protocols have been revised to better identify, manage, and treat infants who are at risk for persistent, recurrent, or severe hypoglycemia. The role of dextrose gels in raising glucose levels or preventing more persistent hypoglycemia, and precautions to reduce risk for recurrence after leaving hospital, are also addressed. This statement differentiates between approaches to care for hypoglycemia during the 'transitional' phase-the first 72 hours post-birth-and persistent hypoglycemia, which occurs or presents for the first time past that point.

Le dépistage et la prise en charge des nouveau-nés à risque d’hypoglycémie

L’hypoglycémie entre les premières heures et les premiers jours suivant la naissance demeure l’une des principales affections qu’observent les praticiens du Canada qui s’occupent de nouveau-nés. Bien des cas vivent une transition physiologique normale à la vie extra-utérine, mais un groupe présente une hypoglycémie pendant une plus longue période. Le présent document de principes expose les principaux enjeux auxquels sont exposés les dispensateurs de soins néonatals, y compris la définition d’hypoglycémie, les facteurs de risque, les protocoles de dépistage, les valeurs de glycémie nécessitant une intervention et la gestion des soins pour cette affection. Les auteurs passent en revue le dépistage, la surveillance et les protocoles d’intervention pour mieux distinguer, prendre en charge et traiter les nouveau-nés à risque d’hypoglycémie persistante, récurrente ou marquée. Ils abordent également le rôle des gels de dextrose pour accroître la glycémie ou prévenir une hypoglycémie plus persistante, de même que les précautions à prendre pour réduire les risques de récurrence après le congé de l’hôpital. Le présent document de principes distingue les approches des soins de l’hypoglycémie pendant la « phase de transition » (les 72 premières heures de vie) de celles de l’hypoglycémie persistante, qui se manifeste ou est constatée pour la première fois après cette période.

The Effect of Continuous Intravenous Glucagon on Glucose Requirements in Infants with Congenital Hyperinsulinism

BACKGROUND/AIMS

Continuous intravenous glucagon is frequently used in the management of severe congenital hyperinsulinism (HI), but its efficacy in these patients has not been systematically evaluated. The aim of this study was to describe the use of continuous intravenous glucagon and to evaluate its effect on the glucose infusion rate (GIR) requirement in infants with HI.

METHODS

Retrospective chart review of children with HI who received continuous intravenous glucagon for prevention of hypoglycemia at the Children's Hospital of Philadelphia between 2003 and 2013.

RESULTS

Forty (22 male) infants were included, and median (IQR) age at glucagon treatment was 29 (23, 54) days. Median glucagon dose was 205 (178, 235) mcg/kg/day and duration of treatment was 5 (3, 9) days. GIR reduced from 18.5 (12.9, 22.8) to 11 (6.6, 17.5) mg/kg/min 24 h after starting glucagon (p < 0.001), and hypoglycemia frequency reduced from 1.9 (1.3, 2.9) to 0.7 (0.3, 1.2) episodes per day. Vomiting (n = 11, 13%), rash (n = 2, 2%), and respiratory distress (n = 15, 19%) were seen during glucagon treatment.

CONCLUSION

An intravenous glucagon infusion reduces the required GIR to maintain euglycemia, decreasing the risks associated with the administration of high fluid volume or fluids with high-glucose concentrations.

Hypoglycemia in the preterm neonate: etiopathogenesis, diagnosis, management and long-term outcomes

Glucose, like oxygen, is of fundamental importance for any living being and it is the major energy source for the fetus and the neonate during gestation. The placenta ensures a steady supply of glucose to the fetus, while birth marks a sudden change in substrate delivery and a major change in metabolism. Hypoglycemia is one of the most common pathologies encountered in the neonatal intensive care unit and affects a wide range of neonates. Preterm, small for gestational age (GA) and intra-uterine growth restricted neonates are especially vulnerable due to their lack of metabolic reserves and associated co-morbidities. Nearly 30-60% of these high-risk infants are hypoglycemic and require immediate intervention. Preterm neonates are uniquely predisposed to developing hypoglycemia and its associated complications due to their limited glycogen and fat stores, inability to generate new glucose using gluconeogenesis pathways, have higher metabolic demands due to a relatively larger brain size, and are unable to mount a counter-regulatory response to hypoglycemia. In this review we will discuss the epidemiology; pathophysiology; clinical presentation; management and neurodevelopmental outcomes in affected infants and summarize evidence to develop a rational and scientific approach to this common problem.

Glucose production in response to glucagon is comparable in preterm AGA and SGA infants

BACKGROUND AND AIMS

Low plasma glucose concentrations are more often detected in small-for-gestational-age (SGA) than in appropriate-for-gestational-age (AGA) infants. This is ascribed to impaired glucose production due to presumed lower liver glycogen stores in SGA infants. The change in glucose production induced by glucagon is considered to be an indicator of liver glycogen content. We compared the effect of glucagon on glucose kinetics in preterm AGA and SGA infants.

METHODS

In 5 AGA and 5 SGA preterm infants (postnatal age: 3-6 days) glucose production and gluconeogenesis were measured using stable isotopes immediately before and for 1 h after a bolus of glucagon.

RESULTS

After glucagon the plasma glucose concentration and glucose production increased significantly over time (P<0.05 and P<0.0001, respectively). The changes were comparable between AGA and SGA infants. Glycogenolysis contributed 75-80% to the increase in glucose production.

CONCLUSION

The increase in glucose production after glucagon was similar in preterm AGA and SGA infants, and mainly due to an increase in glycogenolysis. Based on the assumption that glycogenolysis is an indicator of liver glycogen content, our data do not support the hypothesis that liver glycogen content is lower in preterm SGA compared to AGA infants after the first postnatal day.

The investigation and management of neonatal hypoglycaemia

Assessment of neonatal glycaemic status requires accurate and reliable measurement of blood glucose concentrations. Most point-of-care technologies are, however, unsuitable for use in neonates. Although the definition of hypoglycaemia remains elusive, current knowledge allows adoption of pragmatic threshold blood glucose concentrations when clinical intervention should be considered. The vast majority of instances of neonatal hypoglycaemia are due to problems with the normal processes of metabolic adaptation after birth, and strategies to enhance the normal adaptive processes should help prevent such episodes. Further investigations and specific interventions should be considered when hypoglycaemia is of unusual severity or occurs in an otherwise low-risk infant.

An inadequate glycaemic response to glucagon is linked to insulin resistance in preterm infants?

AIMS

To define clinical, metabolic, and hormonal characteristics of preterm infants relative to glucagon responsiveness.

METHODS

Two phase study of 78 preterm infants (25-36 weeks gestation) on regular four hourly feeds anticipating discharge home at 36 weeks mean corrected gestation. In phase 1 infants were fasted until hypoglycaemic, or maximally for eight hours. Endocrine and metabolic profiles were obtained at completion. Phase 2 was performed the following day. A feed was omitted and replaced by a bolus dose of intravenous glucagon (100 micro g/kg). Main outcome measures were measurements of blood glucose and lactate concentrations, taken immediately pre-glucagon, and thereafter every 15 minutes for 60 minutes. A rise in glucose concentration of >1 mmol/l (55 infants) was defined as an adequate response to glucagon. An inadequate glycaemic response was <1 mmol/l (23 infants).

RESULTS

Several differences in fasting blood glucose and hormone concentrations were identified in infants with an inadequate glycaemic response to glucagon compared to those with an adequate response: relative fasting hyperglycaemia (mean 3.7 v 3.3 mmol/l, p = 0.008); fasting hyperinsulinaemia (mean 4.3 v 2.6 mU/l, p = 0.014); an increased insulin:glucagon ratio (0.19 v 0.11, p = 0.014), and a lower insulin sensitivity QUICKI index (0.19 v 0.22, p = 0.04). There was no distinctive phenotype to reliably predict response to glucagon.

CONCLUSION

Some preterm infants show an inadequate glycaemic response to glucagon and have features suggestive of insulin resistance. The potential long term implications of such insulin resistance may have appreciable public health consequences.

Continuous infusion of glucagon induces severe hyponatremia and thrombocytopenia in a premature neonate

We report on a 35-week gestation infant who developed severe hyponatremia and thrombocytopenia after continuous infusion of glucagon for the treatment of intractable hypoglycemia. Given these serious side effects,glucagon infusion should be avoided in the treatment of premature infants.hypoglycemia, glucose, small for gestational age. Hypoglycemia is commonly seen in premature infants, and the provision of a standard glucose intake is often not sufficient to maintain euglycemia. For these infants, an increase in glucose infusion to provide 4 to 8 mg/kg/min is initially recommended.1 Should this approach fail, pharmacologic agents such as corticosteroids or diazoxide are indicated.1 When the serum glucose in premature or small for gestational age infants cannot be adequately maintained, a glucagon infusion is now suggested as the best treatment approach.2,3 We report the use of glucagon infusion for the treatment of severe hypoglycemia in a premature infant. A severe hyponatremia associated with transient convulsions and thrombocytopenia was observed in the neonate after treatment. Discontinuation of the glucagon infusion resulted in prompt resolution of these abnormalities.

[Transitory hyperinsulinism with hypoglycemia in asphyxia neonatorum]

BACKGROUND

Hypoglycemia is a well-known complication in neonates small for gestational age and in those with diabetic mothers. Birth asphyxiated infants can develop severe hypoglycemia due to reduced glycogen stores.

CASE REPORTS

The first patient was born at 41 weeks, weighing 3,780 g by emergency cesarean section because of fetal distress. He developed a pneumothorax and hypoglycemia. He was given glucose infusion (at day 4: 20 mg/kg/d). Hyperinsulinism was confirmed: blood levels at 18.3 mU/L on day 1 and 11.7 mU/L on day 2. The infusion rate was gradually decreased. The second patient was born at 39 weeks, weighing 2,780 g by emergency cesarean section because of fetal distress. She needed glucose infusion (24 g/kg/d) because of hypoglycemia with hyperinsulinism (12.8 mU/L on day 2 and 11.7 mU/L on day 3). After 5 days, the infusion of glucose was replaced by oral feeding only.

CONCLUSION

Transient hypoglycemia in asphyxiated newborn infants with hyperinsulinism must be considered even when hypoglycemia may be difficult to prove.

Hypoglycaemia of the newborn: a review

It is almost a century since hypoglycaemia (a reduction in the glucose concentration of circulating blood) was first described in children, and over 50 years since the condition was first recognized in infants. Nevertheless, controversy still surrounds the definition, significance, and management of neonatal hypoglycaemia. Technological developments such as bedside glucose monitoring have, paradoxically, exacerbated rather than eased the situation. This article reviews the literature on hypoglycaemia of the newborn, and covers the following: historical aspects; glucose homeostasis and metabolic adaptation at birth; the effect of low blood glucose levels on the central nervous system; the definition of hypoglycaemia; screening; prevention; treatment; research needs; and concludes with recommendations for prevention and management.

Neonatal blood glucose concentrations: metabolic effects of intravenous glucagon and intragastric medium chain triglyceride

Neonatal hypoglycaemia is a common clinical problem and the traditional treatment for the condition is intravenous glucose administration. The glycaemic effects of two additional treatments were investigated, in a randomised trial, in 23 neonates who were receiving intravenous glucose as treatment for hypoglycaemia. Eleven infants received an intravenous bolus dose of glucagon (200 micrograms/kg) and 12 infants received intragastric medium chain triglyceride (MCT) (5 ml/kg). Blood concentrations of glucose and intermediary metabolites were measured before and one hour after treatment, and, using stable isotope infusion, glucose production rates were calculated. After glucagon, there was a mean rise in blood glucose concentration of 1.6 mmol/l and in the glucose production rate of 2.6 mg/kg/min. After MCT, there was a small mean rise in blood glucose concentration of 0.4 mmol/l, but the effect of MCT on glucose production rate was variable. Intravenous bolus glucagon administration exerted a glycaemic effect which was associated with an increase in glucose production rate. The use of glucagon, as an alternative treatment to intravenous glucose, should be investigated further.