2 Clinical Trials for Various Conditions
Nitrous oxide (N2O) is a gas that is normally used to take away pain and anxiety during painful medical procedures. However, one of its effects is to also make veins appear larger and more visible. This is useful when there is a patient who needs to have an intravenous (IV) needle put in their skin to give them medicine or fluids, but may have veins that are very hard to see or feel. The mechanism of this observed effect is not entirely clear. The purpose of this study is to use an ultrasound to directly measure whether there is an actual change size of veins or change in blood flow in healthy adult volunteers when you give them 50% nitrous oxide, and see whether or not this change in size, or change in flow, is what causes the changes in visibility or palpability of the vein.
This study will determine whether or not saphenous vein \[arterial\] bypass grafts in the leg relax in response to increases in blood flow.