Clinical Research Directory

Fasting Induced Hypoglycaemia in Anaesthetised Paediatric Patients

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.

Liver Glycogen and Hypoglycemia in Humans

The purpose of this research study is to learn more about how sugar levels in the liver affect the ability of people both with and without type 1 diabetes. People with type 1 diabetes do not make their own insulin, and are therefore required to give themselves injections of insulin in order to keep their blood sugar under control. However, very often people with type 1 diabetes give themselves too much insulin and this causes their blood sugar to become very low, which can have a negative impact on their health. When the blood sugar becomes low, healthy people secrete hormones such as glucagon and epinephrine (i.e., adrenaline), which restore the blood sugar levels to normal by increasing liver glucose production into the blood. However, in people with type 1 diabetes, the ability to release glucagon and epinephrine is impaired and this reduces the amount of sugar the liver is able to release. People with type 1 diabetes also have unusually low stores of sugar in their livers. It has been shown in animal studies that when the amount of sugar stored in the liver is increased, it increases the release of glucagon and epinephrine during insulin-induced hypoglycemia. In turn, this increase in hormone release boosts liver sugar production. However, it is not known if increased liver sugar content can influence these responses in people with and without type 1 diabetes. In addition, when people with type 1 diabetes do experience an episode of low blood sugar, it impairs their responses to low blood sugar the next day. It is also unknown whether this reduction in low blood sugar responses is caused by low liver sugar levels. The investigators want to learn more about how liver sugar levels affect the ability to respond to low blood sugar.