Fasting-induced hypoglycaemia in anaesthetised paediatric patients (FIGS): protocol of an opt-out approach to consent for a multicentre cohort study measuring glycaemia and ketonaemia.

Abstract

Hypoglycaemia is a potentially a serious complication of the iatrogenic fasting required to deliver safe anaesthesia. Children may be at a higher risk because of their metabolic immaturity. This is a prospective multi-centre cohort study recruiting children fasting before a procedure under general anaesthesia. Children will have their blood glucose and ketones measured using point-of-care testing on venous blood drawn from a cannula inserted during i.v. or inhalation induction of general anaesthesia. The primary aim is to recruit as many children as possible across the four nations of the United Kingdom, using an opt-out approach to consent, to assess different thresholds used by anaesthetists to define hypoglycaemia and identify risk factors of this metabolic complication. The primary endpoint is the decision by anaesthetists to manage a hypoglycaemia at induction in a large paediatric population. Secondary endpoints are the actual values of glycaemia and ketonaemia and to evaluate the distributions of these parameters in a large paediatric population together with assessing potential risk factors of adverse metabolic responses to fasting (mainly hypoglycaemia, hypoketosis, and hyperketosis). The fasting-induced hypoglycaemia in anaesthetised paediatric patients (FIGS) study aims to recruit over 2000 children across the 4 nations of the United Kingdom. Trial recruitment is in progress starting May 2025 and expected to end May 2026, with analysis and results shared in 2027. This study, using an opt-out approach to consent, will provide a large data set of glycaemia and ketonaemia values in a paediatric population, assessing current practice, identifying risk factors, and building new recommendations for the management of the metabolic risk in fasting children. IRAS 329701 and NCT07259629. 1.8, 14 April 2026.