Closed-Loop Blood Glucose Control in Subarachnoid Hemorrhage (GluCoSAH)

• Applicants: Dr. Thomas Breuer; Professor Dr.-Ing. Steffen Leonhardt
• Subject Area: Biomedical Systems Technology ; Anaesthesiology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 549493132

Critically ill patients often show dysregulation of glucose homeostasis. This is caused by the interaction of various stress-induced regulatory mechanisms and results in hyperglycaemia. Beside other acute diseases, subarachnoid haemorrhage (SAH) is relevant in this context, as up to 75% of SAH patients present with glucose dysregulation. Aneurysmatic SAH is the cerebral leakage of blood following rupture of a vascular aneurysm. It has a high mortality rate (up to 50%) and a high degree of functional impairment. First and foremost, the severity of the haemorrhage is crucial, but complications such as vasospasm or delayed cerebral ischaemia (DCI) are also of considerable importance and worsen the patient's outcome. The latter two are induced inter alia by hyper- and hypoglycaemia and glucose variability. Until 2001, stress-induced hyperglycaemia was given little attention in therapy. This changed after the monocentric study by Van den Berghe et al.. In this study, the benefits of tight glycaemic control (TGC) were demonstrated for the first time by the corresponding reduction in mortality. However, subsequent randomized multicenter studies, most notably the NICE-SUGAR Trial 2009, could not confirm the benefit of TGC. Hypoglycaemia, which itself was associated with increased mortality, occurred significantly more often in the TGC group. These results were criticised, in part, because glucose measurement was carried out intermittent and manual, delaying the detection of hypoglycaemia. Currently, moderate blood glucose control (<180mg/dl) is the goal of intensive care therapy. Technical assist-systems that enable near-continuous blood glucose measurements exist, but are rarely used because glucose regulation with insulin is currently based on manual calculation aids and individual experience and demands human resources, so that the benefits of near-continuous glucose monitoring without regulation seems to be marginal. The aim of the proposal is therefore to establish an automated blood glucose monitoring and regulation system and thus to achieve continuous tight glucose control, while avoiding hypoglycaemia. For this purpose, first a closed-loop glucose regulation system is developed in vitro, which second is implemented in vivo in a SAH rat model. After 72 hours of treatment, a histological quantification of vasopasm will be performed, inter alia. If automated tight glucose control turns out to be more effective than conventional moderate glucose regulation, this could be the starting point for profound changes in intensive care glucose regulation and might result in lower mortality, not only in SAH patients.

• DFG Programme: Research Grants