Edema has many possible causes: 1  Prolonged standing or sitting, especially in hot weather, can cause excess fluid to accumulate in the feet, ankles and lower legs. 2  Tiny valves inside the veins of the legs can become weakened, causing a common problem called venous insufficiency.
Cars with nitrous-equipped engines can be identified by the purge of the delivery system that most drivers perform prior to reaching the starting line. A separate electrically operated valve is used to release air and gaseous nitrous oxide trapped in the delivery system.
Nitrous oxide/oxygen (N2O-O2) is a blend of two gases â oxygen and nitrous oxide. A fitted mask is placed over the nose and, as the patient breathes normally, uptake occurs through the lungs. At the end of treatment, it is eliminated after a short period of breathing oxygen and has no lingering effects.