Microdialysis and Jugular Bulb Glucose Profiles During Hyperglycaemic Clamping in Patients With Severe Acute Brain Injury (CLAMP)

Acute brain injury is a serious condition that often results in admission to an intensive care unit. Some of the most seriously ill patients are fitted with multimodal neuromonitoring, a newer monitoring modality that can, among other things, measure oxygen tension and sugar levels in brain tissue. It is common clinical practice, but the interaction between the body's sugar levels and the brain's sugar levels is not sufficiently elucidated.

The study will investigate the relationship between the body's sugar levels, measured in arterial and venous blood, and the brain's sugar level, measured by microdialysis, in patients with severe acute brain injury.

Furthermore, we hope to be able to use our measurements to set up a mathematical model for the brain's sugar uptake.

Study Overview

• Status: Not yet recruiting
• Conditions: Acute Brain Injury
• Intervention / Treatment: Other: Hyperglycaemic clamp

• Study Type: Interventional
• Enrollment (Estimated): 14
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Anne-Sophie Worm Fenger, MD; Phone Number: +4524624359; Email: anne-sophie.fenger.03@regionh.dk
• Study Contact Backup: Name: Kirsten Møller, MD, PHD, DSC; Phone Number: 35451616; Email: kirsten.moller@dadlnet.dk

Study Locations

• Denmark
  • Copenhagen, Denmark, 2100
    • Rigshospitalet
    • Contact: Anne-Sophie Worm Fenger, MD; Phone Number: +4524624359; Email: anne-sophie.fenger.03@regionh.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Age ≥ 18 years.
• Admission to the neuro-ICU at Rigshospitalet.
• Multimodal neuromonitoring

Exclusion Criteria:

• Closest relative does not understand written and spoken Danish or English.
• Patients with known diabetes mellitus upon admission.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Other: Hyperglycaemic clamp; The purpose of hyperglycaemic clamping is to raise the blood glucose level to a fixed plateau and maintain the plateau for at least one hour to observe a steady-state blood glucose concentration. The investigators intend to perform the hyperglycaemic clamping procedure one time in all 14 patients following an overnight fast and aim for a fixed blood glucose level above 8 mmol/L. The patient will have an arterial line placed in the radial artery, a retrograde catheterization of the jugular bulb and a venous line for infusions of glucose, potassium, and isotonic saline. To maintain potassium levels at wanted levels, an isotonic saline solution containing potassium will be infused continuously and arterial samples of potassium and glucose will be measured at minimum every 10 minutes from the start of the intervention.

Other: Hyperglycaemic clamp; Following an overnight fast, the investigators will perform simultaneous samples from the arterial line, the venous line, and microdialysis and consider these samples as baseline values. If the patient's blood glucose level is at 8-10 mmol/L at baseline, the investigators will not proceed with the intervention and instead evaluate if the intervention can take place the following day. After baseline values are measured, intravenous glucose 20% (200g/1,000 ml) is infused to raise the glucose levels in both plasma and extravascular glucose compartments with approximately 3 mmol/L.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
(Change in) MD-glucose (mmol/L)	Change in) MD-glucose (mmol/L) over time as a function of (a set change in) arterial blood glucose (mmol/L)	Throughout the intervention, approximately five hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Jugular vein glucose (mmol/L) over time as a function of arterial blood glucose.	Jugular vein glucose (mmol/L) over time as a function of arterial blood glucose (mmol/L)	Throughout the intervention, approximately five hours
Lactate-pyruvate-ratio (LP-ratio) as a function of arterial blood glucose.	Two other microdialysis paramethers, lactate and pyruvat, will be assessed to evaluate the lactate-pyruvate ratio over time as a function of arteriel blood glucose.	Throughout the intervention, approximately five hours.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mathematic model of transport of glucose over the blood brain barrier.	Mathematic model of transport of glucose over the blood brain barrier.	Throughout the intervention, approximately five hours.

Collaborators and Investigators

• Sponsor: Rigshospitalet, Denmark

Study record dates

Study Major Dates

• Study Start (Estimated): May 8, 2024
• Primary Completion (Estimated): October 8, 2025
• Study Completion (Estimated): December 31, 2026

Study Registration Dates

• First Submitted: April 25, 2024
• First Submitted That Met QC Criteria: April 30, 2024
• First Posted (Actual): May 1, 2024

Study Record Updates

• Last Update Posted (Actual): May 1, 2024
• Last Update Submitted That Met QC Criteria: April 30, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Keywords: Glucose; Intensive care; Anaesthesiology; Neurointensive care; Hyperglycaemic clamp; Acute brain injury; Multimodal neuromonitoring
• Additional Relevant MeSH Terms: Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Craniocerebral Trauma; Trauma, Nervous System; Brain Injuries; Wounds and Injuries
• Other Study ID Numbers: 23072860

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