Fasting Induced Hypoglycaemia in Anaesthetised Paediatric Patients (FIGS)

Fasting is a requirement to safely anesthetise patients referred for elective procedure, using the traditional 6/4/2 rule (6h for solid food or formula milk, 4h for breast milk and 2h for clear fluids), applied to all patients regardless of their age or weight. Reducing the aspiration risk however puts young children at higher risk of hypoglycemia due to the immaturity of their endocrine system and absence of metabolic reserves. The Association of Paediatric Anaesthetists of Great Britain and Ireland recommends that during day case surgery the majority of children may be given fluids without dextrose, provided blood glucose is monitored. Recent statements recommend continuing fluids until 1h before the procedure or even to give fluids when anesthetists sent for the patients. Hypoglycemia is rare in children above 2 years of age. Although the definition of hypoglycemia can differ, a threshold of 3.6mmol/l is often used given the potential neurological harm existing below this value. There is no consensus on the definition of hypoglycemia in children being fasted prior to general anesthesia, nor when nor how to treat it. Measurements are done for complex surgeries or patients deemed at risk according to the anesthetists. An audit was run in 2017 at the " Evelina London Children's Hospital ", Guy's and St Thomas' National Health Service Foundation Trust, identifying 8% of children below 2 years of age as hypoglycemic. Recent review of our Incident Reporting Systems identified 3 cases, in otherwise fit and healthy children, referred for colonoscopy with initial hypoglycemia followed by rebound hypoglycemia after management. There is an urgent need to establish a clear definition of hypoglycemia and investigate risk factors in paediatric patients referred for elective procedures under general anesthesia.

Study Overview

• Status: Recruiting
• Conditions: Anesthesia; Pediatrics; Hypoglycemia; Iatrogenic

• Study Type: Observational
• Enrollment (Estimated): 6580

Contacts and Locations

• Study Contact: Name: Benjamin Blaise, MD PhD; Phone Number: +447478741874; Email: gstt.figsstudy@nhs.net

Study Locations

• United Kingdom
  • London, United Kingdom, EC1V 2PD
    • Completed
    • Moorfields Eye Hospital
  • London, United Kingdom, SE17EH
    • Recruiting
    • Evelina London Children's Hospital
    • Contact: Benjamin Blaise Blaise, MD PhD; Phone Number: +447478741874; Email: gstt.figsstudy@nhs.net
  • Devon
    • Exeter, Devon, United Kingdom, EX2 5DW
      • Recruiting
      • Royal Devon University Healthcare NHS Foundation Trust
      • Contact: Philippa Dix, FRCA; Phone Number: +441392411611; Email: philippa.dix@nhs.net

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult
• Accepts Healthy Volunteers: N/A

• Sampling Method: Non-Probability Sample

Study Population

Pediatric patients fasting for a procedure under general anesthesia

Description

Inclusion Criteria:

• All American Society of Anesthesiology score (ASA) 1 - 3 children aged 1 month to 18 years presenting for an elective procedure involving general anaesthesia during the defined study period
• All elective cases, day cases will be included (patient's admitted the night before for bowel preparation prior to elective colonoscopy should also be included)
• Planned expedited cases in ASA 1 / 2 children should be included, for example nail bed repairs, lacerations, foreign body (in ear / eye / nose), simple fractures for manipulation under anesthesia / k-wires
• MRI, radiology and dental cases will be included provided the patient receives a general anaesthetic

Exclusion Criteria:

• Children aged less than 1 month
• Procedures performed under oral sedation or local anaesthesia only
• ASA status 4 and 5
• Children with any endocrine or metabolic condition or who have a fasting plan prior to general anaesthesia for glucose control:
• Type 1 or 2 diabetes mellitus, medium chain acetyl Co-enzyme A, maple syrup urine disease, glycogen storage disease, galactosaemia, urea cycle defects, familial hypercholesterolaemia, congenital disorders of glycosylation, lysosomal storage disorders, organic acidaemias, mitochondrial disorders, adrenal gland disorders, adrenoleukodystrophy, growth disorders, lipid disorders, multiple endocrine neoplasia type 1 and 2, pituitary disorders.
• Emergency and oncology procedures as these children will have different risk factors for hypoglycaemia
• Anaesthetic involvement in critically ill children e.g. airway management in emergency department, pediatric intensive care unit
• Children on glucose containing intravenous solutions or total parenteral nutrition pre-operatively
• Children on systemic steroid treatment (oral / intravenous). Children on inhalers / topical steroids should be included

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Clinical definition if hypoglycemia	Blood glucose values triggering a response from the anaesthetists with initiation of a hypoglycaemia treatment following a blood glucose measurement during anaesthetic induction	Immediately/within five minutes after anesthesia induction

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
4mmol/l as a suitable threshold of hypoglycemia	Number of patient with a blood glucose measurement below 4mmol/l and being treated as hypoglycaemic by an anaesthetist following a blood glucose measurement during anaesthetic induction	Immediately/within five minutes after anesthesia induction
Distribution of glycemic measurements in fasting children	Blood glucose values in children undergoing elective procedure under general anaesthesia.	Immediately/within five minutes after anesthesia induction
Age as a risk factor of hypoglycaemia	Number of children below 24 months of age reported as hypoglycaemic by an anaesthetist following a blood glucose measurement during anaesthetic induction	Immediately/within five minutes after anesthesia induction
Weight as a risk factor of hypoglycaemia	Number of children weighing less than 10kg and considered as hypoglycaemic by an anaesthetist following a blood glucose measurement during anaesthetic induction	Immediately/within five minutes after anesthesia induction
Distribution of blood ketone measurements in children fasting	Blood ketone values in children undergoing elective procedure under general anaesthesia.	Immediately/within five minutes after anesthesia induction

Collaborators and Investigators

• Sponsor: Guy's and St Thomas' NHS Foundation Trust
• Collaborators: Nova Biomedical; Kings Health Partners; Evelina London Children's Charity

Study record dates

Study Major Dates

• Study Start (Actual): May 12, 2025
• Primary Completion (Estimated): March 30, 2026
• Study Completion (Estimated): January 12, 2027

Study Registration Dates

• First Submitted: July 16, 2024
• First Submitted That Met QC Criteria: November 20, 2025
• First Posted (Actual): December 2, 2025

Study Record Updates

• Last Update Posted (Actual): December 2, 2025
• Last Update Submitted That Met QC Criteria: November 20, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Metabolic Diseases; Glucose Metabolism Disorders; Nutritional and Metabolic Diseases; Hypoglycemia
• Other Study ID Numbers: 329701

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No