This is part of a series of studies investigating the potential therapeutic use of low dose nitrous oxide in the treatment of cerebral vasospasm, a condition which occurs following brain injury and stroke. We are looking to see if the increased blood flow to the brain seen with nitrous oxide is caused by an increase in cerebral metabolism. This would need to be excluded if nitrous oxide is to be considered as a potential treatment.
Conditions
Interventions
Trade Name: Medical Nitrous Oxide
Product Name: Nitrous oxide
Pharmaceutical Form: Inhalation vapour*
Sponsors
University of Nottingham
Eligibility
Sex/Gender
All
Inclusion criteria
Inclusion criteria: Inclusion criteria: Males and Females aged between 18 and 50 Are the trial subjects under 18? Number of subjects for this age range: F.1.2 Adults (18-64 years) yes F.1.2.1 Number of subjects for this age range F.1.3 Elderly (>=65 years) F.1.3.1 Number of subjects for this age range
Exclusion criteria
Exclusion criteria: People with history or evidence of a systemic illness or vascular disease On prescription medication which may affect cardiovascular system e.g. Beta blockers, Calcium channel antagonists Cardiac pacemaker or mechanical heart valve Implanted electrical devices e.g. hearing aid, nerve stimulator, cochlear implant, programmable shunt Any evidence of neurological disorder including brain surgery, aneurysm clip Smokers Pregnant* or lactating females Metal fragments in your eyes Metal clips, pins, plates, implants, coils, screws, shrapnel or similar in your body *In females pregnancy will be excluded by an hCG test within 24 hours preceding MRI scan
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Main Objective: What is the effect of inhaling low dose nitrous oxide, otherwise known as laughing gas, on blood supply, to different areas of the brain. This can be described as 'changes in regional blood flow'. This can be achieved by taking pictures of the brain with a special scan machine which uses a magnet instead of X rays. These pictures will show the blood supply to the various parts of the brain before and during the breathing of laughing gas. Thus the differences between the two images can be studied.;Secondary Objective: We will look to see if there are any changes in oxygen and nutrient usage by the brain and changes in brainwaves in response to breathing laughing gas. Oxygen usage indicates metabolism of the brain tissue, ie fuel requirements. We will relate this information to to the findings on blood flow to the different areas of the brain. We want to establish if there is a link between increased blood flow and fuel requirements or nerve activity(as seen by brainwaves) in the brain. ;Primary end point(s): To quantify the effect of 30% inspired concentration of nitrous oxide on regional CBF (cerebral blood flow) in healthy volunteers. Techniques known as Arterial spin labeling (ASL) use magnetic labeling of blood to show in an image the amount of blood perfusing different areas of the brain. Contrast agents are not required for these techniques. This perfusion measurement is completely noninvasive. ASL techniques will measure the quantity of regional perfusion at baseline (room air), 40% oxygen in medical air, and 40% oxygen in medical air with 30% nitrous oxide. Blood flowing into the imaging slice exchanges with tissue water, altering the tissue magnetization. A perfusion-weighted image can be generated by the subtraction of an image in which inflowing spins have been labeled from an image in which spin labeling has not been performed. Quantitative perfusion maps can be calculated if other parameters (such as tissue T1 and the efficiency of s | — |
Countries
United Kingdom
Outcome results
None listed