Hypoglycaemia : preterm infants

All staff involved the screening and management for hypoglycaemia should be familiar with the signs and symptoms of hypoglycaemia.

A late preterm infant who is at risk of hypoglycaemia should be screened with regular monitoring of the capillary glucose concentrations. 

Near patient testing devices tend to be less accurate in the lower range, especially < 2.0mmol/l [1] and therefore all low values (≤2.6mmol/L) require confirmation using blood gas analysis as this is considered the gold standard for measuring blood glucose.

Hand held glucometers should meet ISO standards (ISO15197:2013). If a handheld glucometer is used, low levels must be confirmed using an accurate method as cot-side monitors may be inaccurate in the lower ranges and require checking using a True Blood Glucose (TBG) to guide therapy. A TBG can be obtained by sending a formal laboratory sample but significant delays can occur in obtaining a result, alternatively a TBG can also be obtained from a blood gas analyser, where available, as these are equally reliable [2]. All units must ensure they have readily accessible methods for accurate measurement of a TBG . Each unit must be aware of the characteristics of any near patient testing device used in their hospital. 

1. Identify all late preterm babies at birth and commence a hypoglycaemia/NEWS monitoring chart in labour ward. All babies should be risk assessed for criteria for hypoglycaemia monitoring and/or NEWS monitoring prior to leaving a labour ward environment
   
   
2. Aim to prevent hypoglycaemia
   • Keep the baby warm - dry the baby well at birth, cover the baby whilst receiving skin to skin contact, put a hat on and avoid bathing until the temperature is stable and a warm environment is assured. This is likely to be after 24 hours of age. When dressing the baby, ensure that clothing is warmed first. Utilise skin-to-skin to warm the baby whenever needed.
   • Skin to skin and the first feed – it is vital that this baby has the opportunity to have uninterrupted skin contact immediately after the birth (including instrumental and caesarean birth). The baby should have the full “magical hour” episode.
     Do not assist the baby to feed too early before it is ready to attach correctly and feed effectively.  Ideally the first feed should commence within the first 60 minutes. Assist the mother to recognise feeding cues (rapid eye movements under the eye lids, mouth and tongue movements, body movements and sounds, sucking on a fist).
     If the baby has not feed by 90 minutes after the birth or is reluctant to feed, follow reluctant feeder guidance,  then start hand expressing and give the colostrum to the baby.
     For women who wish to formula feed give 10-15ml/kg 3 hourly.
   • Blood glucose monitoring and clinical surveillance – The first blood glucose should be taken prior to the second feed usually at around 2-4 hours old [3] [4]. Check the baby’s temperature, tone and respiratory rate at least 3 hourly to coincide with blood glucose measurements. Ensure that the baby is alert and normally responsive for their age and gestation. If the baby is unwell or has clinical signs of hypoglycaemia check the blood glucose immediately and alert the Paediatrician urgently.
   • Encourage effective feeding – Following the second feed, continue to offer lots of feeding opportunities, at least 3hly until blood glucose measurements have been > 2.5mmol on three consecutive occasions. Reinforce feeding cues; teach hand expressing and biological nurturing techniques to the mother early on as these will be essential for the late preterm baby who needs to feed often. Continue feeding support until mother and midwife are satisfied that effective feeding is established.
3. Screen capillary blood samples for hypoglycaemia immediately prior to each feed (3 hourly) using a cot-side testing device. Aim to maintain a pre-feed blood glucose of ≥2.5 mmol/l.  If blood glucose values <2.5 mmol/l are obtained follow the management pathways.
   
   
4. Discontinue monitoring when blood glucose concentrations have been > 2.5mmol/l on three consecutive occasions at least 3 hours apart. Observe feeding in hospital for at least a further 24 hours ensuring it is effective while remaining vigilant for the signs of hypoglycaemia. If signs of hypoglycaemia develop or there are concerns about feeding discuss with medical staff and consider taking a further blood glucose.
   
   
5. After discontinuing regular glucose monitoring, continue feeding input
   • If the baby is alert and keen to waken and feed, then promote responsive feeding.
   • If the baby is still a bit sleepy, continue to waken and proactively offer feeds.
6. Do not transfer babies with risk factors for impaired metabolic adaptation and hypoglycaemia to community care  for at least 24 hours until you are satisfied that the baby is maintaining blood glucose levels and feeding well.

Normal Pathway – Blood Glucose >2.5mmol/l

• If 3 consecutive values, at 3hly intervals, fall in this zone, monitoring may cease.
  
  

Green Zone – Blood Glucose 2.0 – 2.5 mmol/l - Increased vigilance and feeding support

• Offer an additional feed if willing and continue frequent feeds at least 3hly thereafter.
• Observe a breastfeed and ensure good attachment and effective feeding. Encourage skin contact and biological nurturing. Proactively encourage hand expressing.
• If two consecutive measurements fall within the Green Zone - -→ Treat as Amber Pathway

Amber Zone – Blood Glucose 1.0 - 1.9 mmol/l - Supplement and Paediatric review

• Inform Paediatrician
• Feed volumes must be increased.  Initially by an extra 10ml/kg/feed above current intake. 
  For breast fed babies this will require top-ups. Top ups should be EBM* if sufficient available, otherwise formula should be used. Donor Breast Milk is an option and ensure families are aware this is available and can be used in this scenario.
• Measure Glucose 1hr post feed.  If >2.5mmol/l, continue supplements and resume prefeed testing
• If subsequent prefeed glucose values have improved to lie in the green zone but still remain <2.6 mmol/l, increase top up volumes by one further increment of 5-10 ml/kg/feed
• If baby will not take, or does not tolerate, supplements then admit to SCBU/TC  for NG feeds
• Two consecutive measurements in the Amber Zone --→ Treat as Red Pathway
  
  

Red Zone – Blood Glucose <1.0 mmol/l - Admit to SCBU

• Notify Paediatrician immediately for all babies who are symptomatic or whose blood Glucose is <1.0mmol/l
• Admit to SCBU and check TBG on the blood gas machine. Take one of the following actions immediately:
  
  

1- Babies who are asymptomatic and have not had an adequate feed prior to admission

• Administer an immediate feed of at least 10 ml/kg (EBM by preference or formula).
  If the baby will not feed orally, administer the feed by NG tube.  Re-check blood glucose after 1hr.
• If > 2.6 mmol/l resume frequent, 3 hly, feeding of at least 10ml/kg/feed and monitor Glc before each feed
• If 2.0-2.6 mmol/l start hourly feeds of 5ml/kg/feed (120ml/kg/day) check glucose before each feed (hourly).
• If < 2.0 mmol/l after initial feed or if still hypoglycaemic on 1hly feeds, treat with IV Glucose as   below 

2 - Babies who cannot tolerate enteral feeds or whose blood glucose remains <2.6mmol/l despite frequent NG feeds (as above)  OR who become symptomatic

• Site IV and, if symptomatic or Glc <1.0mmol/l, give 2.5ml/kg 10% Dextrose slow IV bolus
• Start 90ml/kg/day of 10% dextrose or TPN
• Enteral feeds may continue initially but if hypoglycaemia persists despite increasing volumes of IV Glucose then a temporary cessation of enteral feeds may be required.
• Monitor Blood Glucose hourly and titrate the glucose infusion rate to achieve normoglycaemia
• If the baby has an ongoing requirement of ≥120 ml/kg/day of milk / 10% glucose to maintain normoglycaemia, refer to the guideline for refractory hypoglycaemia  

*It is usual to use the mother’s own breast milk for top-ups.  However mother’s own EBM may be unavailable or insufficient for the required volume of top-up.  Under these circumstances donor EBM or infant formula should be used.

Parent information leaflet (pdf): Protecting your baby from low blood sugar

Hypoglycaemia Monitoring Chart - Late Preterm Infants 34-36+6 Weeks Gestation (pdf)