Introduction
Hypoglycaemia is the most common metabolic disorder of the neonate, and occurs in 5-15% of all neonates. Untreated hypoglycaemia has a high mortality rate, and prolonged or severe neonatal hypoglycaemia can result in brain injury and adverse neurological outcomes; which may impact the
neonate well into childhood.
During intrauterine life, the neonate receives a continuous supply of glucose from the placenta via the umbilical cord. After birth, the umbilical cord is cut and the glucose supply ceases. This, coupled with a transient increase in insulin production cause a drop in blood
sugar levels. Immediately after birth, the neonate must adapt and stimulate its own glucose supply with the assistance of enteral feeds (or intravenous fluids if the newborn is unable to feed).
Even with immediate commencement of breastfeeding/formula feeding/intravenous glucose, there is an expected period of less than 72 hours post-birth in which the glucose levels fluctuate in the neonate. The balance of glucose supply and glucose utilisation in the neonate is
impacted by various risk factors and/or underlying conditions.
When there is an imbalance between glucose supply and glucose utilisation, the neonate may experience hypoglycaemia – which is defined as a blood glucose measurement of below
2.6mmol/L
Aim
This guideline will provide information about the risk factors, clinical signs, investigations, and treatmentof neonatal hypoglycaemia.
Definition of terms
Blood glucose
level (BGL): Blood glucose measurement from a bedside glucometer, which is less accurate at low readings.
Capillary blood
gas (CBG): blood test less invasive than arterial blood gas collected from infant heel,
see here for collection instructions
Hypoglycaemia: A TBG or BGL below 2.6mmol/L
True blood glucose (TBG): Blood glucose measurement from laboratory or blood gas analyser, the most accurate reading of a blood glucose
Risk Factors
Most neonates with hypoglycaemia are initially asymptomatic, and therefore, early detection of hypoglycaemia is based on surveillance of neonates who have risk factors for hypoglycaemia.
Risk factors should be assessed on admission, and a blood glucose level (BGL) ordered if the neonate has 1 or more risk factors.
Table one: Risk factors include, but are not limited to
Maternal Factors |
- Maternal diabetes
- Maternal medication use – i.e. Beta Blockers
|
Weight outside normal
parameters |
- Small For Gestational Age (SGA) less than 10% Percentile
- Large for Gestational Age (LGA) greater than 90% Percentile
- Intrauterine Growth Restriction (IUGR)
|
Premature birth |
- Less than 37 Weeks Gestational Age (GA)
|
Inborn errors of metabolism |
- Glucose-6-phosphate dehydrogenase deficiency, G6PD
- Fatty acid oxidation disorders
- Glycogen Storage Disease
|
Congenital disorders |
- Beckwith- Wiedemann syndrome
- Congenital hyperinsulinism
- Congenital hormone deficiencies
- Congenital adrenal hyperplasia
|
Perinatal stress |
- Respiratory distress, hypoxia, asphyxia
- Hypothermia
- Sepsis
|
Nil by mouth |
- Lack of IV Fluids
- Disruption of IV Fluids due to PIVC issues
|
Intake issues |
- Fasting
- Poor suck
- Vomiting
|
Assessment Clinical Signs
Neonatal hypoglycaemia is frequently asymptomatic and only detected when BGL testing is performed due to risk factors identified. Clinical signs of neonatal hypoglycaemia may also be shared or similar to the clinical signs of other conditions such as
sepsis of asphyxia.
Therefore, if a neonate is presenting with clinical signs, it is important to get a true blood glucose (TBG) via a capillary blood gas (CBG) as soon as possible for diagnosis and treatment.
Clinical signs of
hypoglycaemia:
Central nervous
system excitation:
- Jitteriness
- High-Pitched Cry
- Seizures
Central nervous
system depression:
Lethargy
Apnoea
Poor Feeding
Investigations
All neonatal admissions presenting with risk factors for hypoglycaemia should have a CBG or a TBG on admission or if there is any clinical signs of hypoglycaemia. Depending on the result, a plan can be discussed with the medical team.
A TBG should be taken as a capillary blood gas (CBG) for an instant result, when clinical signs are noted, so the potential hypoglycaemia can be treated as quickly as possible.
A capillary bedside
glucometer reading is unreliable at low readings; hence it is important to confirm
that the TBG is less than 2.6 mmol/L which can be done by CBG.
Glucose Infusion Rate (GIR/GUR)
The Glucose Infusion Rate (GIR) is a measurement of how much glucose (as mg/kg/min) a neonate is receiving. When a neonate has hypoglycemia, their GIR should be calculated to make sure they are receiving an adequate dose of glucose.
Initially these ranges can be used as a guide, but they can be increased if hypoglycemia persists.
Term Neonates: 4-6mg/kg/min
Premature Neonates: 6-8mg/kg/min
The
Glucose Delivery Calculator (NICU Tools) allows you to calculate the GIR of the neonate – including IV and enteral intake.
Table two: Parenteral nutrition glucose concentrations
Standard TPN solutions used in Butterfly Ward: |
N1 |
100g/L Glucose = 10% Glucose |
N2 |
125g/L Glucose = 12.5% Glucose |
N3 |
200g/L Glucose = 20% Glucose |
If a neonate requires greater than 10mg/kg/min of glucose to keep TBG greater than 2.6mmol/L, hyperinsulinism should be suspected and the priority blood tests (below) should be taken.
Additional tests to establish causes
Further blood tests are required if it is suspected that the hypoglycaemia has an underlying cause.
BGL done via a glucometer is ordered as a POCT (point of care test) and can be done by nursing staff. The result is then entered either via the Manage Labs tab or in the Hub.
Medical Staff must order all other tests, including CBG, prior to collection. In EMR the IP Hypoglycaemia Order Set includes picture of vials and which tests to order.
The following blood tests should be done while the neonate is hypoglycaemic. Appropriate tubes and amounts indicated in brackets. Serum Gel (Brown); Fluoride Oxalate (Yellow); Lithium Heparin (Orange). These samples should be venous or arterial, capillary specimens are not suitable.
Urine – first voided urine after hypoglycaemic episode, requesting glucose, ketones, reducing substances and amino and organic acids
Support non-pharmacological interventions to minimise pain and discomfort (wrapping, comfort care, and sucrose if appropriate) should be provided during blood tests.
Table three: Testing
Priority Blood Tests (Medical staff MUST
order these tests prior to
collection) |
True Glucose
(Yellow/Brown, 0.3mL) |
Insulin
(Brown, 0.5mL, Ice) |
Growth Hormone
(Brown 0.7mL, tested with Cortisol) |
Cortisol
(Brown, 0.7mL tested with GH) |
Ketone
(Blood Glucometer, Urine Dipstick) |
Lactate
(on CBG) (is this Yellow 0.3mL) |
Additional blood tests |
C-Peptide
(Brown, 1mL, Ice) |
Ammonia*
(Orange, 0.5mL, Ice) |
Free Fatty Acids
(Yellow, 1mL) |
Amino Acids
(Orange, 1mL, Ice) |
Carnitine
(Orange, 1mL) |
Liver Function Tests (LFT)
(Brown, 0.5mL) |
See also Specimen
Collection handbook
Treatment
When a neonate is hypoglycaemic – prompt treatment is the goal. The aim of the treatment is to quickly bring the neonates BGL greater than 2.6mmol/L.
A successful treatment plan should include identifying and treating causes, underlying aetiology for the hypoglycaemia.
While treating the neonate’s hypoglycaemia (as per the below flowchart) it is also important to keep them “warm”, “pink”, “sweet” and “calm”.
- Warm – Hypothermia increases a neonate’s metabolism, using
glucose stores, driving hypoglycaemia. It also causes hypoxia, which results in
further hypoglycaemia.
- Pink – Hypoglycaemia results in hypoxia because it reduces
surfactant production and vasoconstriction, driving up work of breathing, leading
to respiratory distress – which then forms a feedback loop and results in
further hypoglycaemia
- Sweet – Maintaining a normal BGL or treating a low/high BGL
- Calm – minimising energy use
and stress, both of which significantly impact the above systems
Refer to the
Management of the neonate and/or
Preterm infant management guideline for optimising basic care of the neonate
Increasing IV Glucose Concentrations (for adjusting
the glucose infusion rate GIR)
Fluids with glucose concentration above 12.5% should be administered through a central venous
line (either an umbilical catheter or peripherally inserted central catheter) to reduce risk of extravasation/thrombophlebitis.
As per the RCH’s Paediatric Injectable Guidelines:
Intravenous fluid additive calculations to prepare 500 mL.
The use of a
Glucose 50% concentration infusion is via neonatal consultant approval only and administered only within PICU/NICU.
Glucagon Treatment
In hypoglycaemia, a single bolus injection of glucagon can sometimes increase the blood glucose level enough to make further treatment unnecessary.
A glucagon continuous infusion is the next step once maximum glucose concentration has been reached and the neonate remains hypoglycaemic.
- A Glucagon IM stat injection of glucagon 30-100mcg/kg (0.03-0.1mg/kg), should be given when the hypoglycaemic neonate is symptomatic but does not have IV access.
- If hypoglycaemia persists despite IV fluids, a second dose of 200mcg/kg dose may be given (6-12 hours after first).
- Some infants of diabetic mothers may require up to 300mcg/kg to a maximum dose of 1mg (total dose, not per kg).
- A Glucagon IV
Continuous Infusion should be commenced only when the neonate remains hypoglycaemic despite having increased the GIR (maximum) with a glucose concentration of 20% at appropriate TFI.
- Start Glucagon Infusion with 5mcg/kg/hour and adjust according to response up to 20mcg/kg/hr
Administering
Buccal Glucose 40% Gel
Glucose 40% Gel can be administered into the buccal space and enters the systemic circulation via the lingual and jugular veins. Administration of buccal glucose should be immediately followed by enteral feeds, has been shown to increase BGL and reduce the need for IV
fluids. Studies have shown this is most effective in babies less than 72 hours of age experiencing suspected transient hypoglycaemia.
At RCH this
treatment is appropriate for babies who have asymptomatic hypoglycaemia and
have no IV access and should be followed up with an enteral feed. Buccal
glucose should be ordered by a doctor before administration.
Medication: Oral gel, 15g glucose in 37.5g (Glucose 40%)
Dose is 200mg/kg (0.5mL/kg) massaged directly into a neonate's buccal space, followed by a feed (breastfeed, EBM or formula) orally or NGT.
Buccal
Administration Procedure
- With an oral syringe, measure out 200mg/kg (0.5mL/kg) of 40% glucose gel.
- With a gloved hand, using gauze or a large swab – dry both sides of buccal mucosa (inside lips, above gum line and along cheeks).
- Using gloved fingers or a large swab massage the gel into the mucosa, splitting the dose between each side. Do not squirt directly into mouth or at back of throat
- Commence enteral feed – either breastfeed, EBM or formula.
Education and Family Support
Education for family members regarding hypoglycaemia is an important aspect of the neonate’s holistic care.
Education may include:
- Risk factors and causes of neonatal hypoglycaemia
- Clinical manifestations of neonatal hypoglycaemia
- Investigations of neonatal hypoglycaemia
- Basic nursing management to prevent and manage of neonatal hypoglycaemia
- Medical management of neonatal hypoglycaemia
Family-centered care must always be upheld during clinical concerns of the neonate. Communication of a hypoglycaemic event, investigations taken and subsequent results should be discussed with the family when appropriate. Communication with the family can be documented within EMR progress notes.
Companion documents
Evidence table
Click here to view the evidence table.
Please remember to
read the disclaimer.
The revision of this nursing guideline was coordinated by Rose Wilson, RN, Butterfly Ward, and approved by the Nursing Clinical Effectiveness Committee. Updated February 2023.