"LAUGHING GAS" • DENTAL SURGERY (30% NO + 70% O2) • USED WITH OTHER ANESTHETICS (HALOTHANE) to increase their uptake and analgesic activity • high MAC (100%) • S/E: post-op N&V, oxidizes cobalt in B12 -- megaloblastic anemia, fetal abnormalities, diffusion hypoxia- replaces O2 in lungs