title: Fixed performance oxygen masks. Hypoxic hazard of low-capacity drugs.
abstract: Four recently introduced low-capacity fixed performance oxygen therapy masks have been compared with the established Ventimask design. Under conditions of varying peak inspiratory flow rate the low-capacity devices all permit a variable amount of air admixture with a consequent fall in the inspired oxygen concentration. It is concluded that low-capacity venturi masks are not true fixed performance devices under all circumstances. The Ventimasks satisfy their specifications under all test conditions. A case is made for more rigorous assessment of new so-called "fixed performance" oxygen therapy devices before marketing is permitted.
mesh_terms: D004867:Equipment Design; D004869:Equipment Safety; D006801:Humans; D000860:Hypoxia / Q000209:etiology; D008397:Masks; D010100:Oxygen / Q000008:administration & dosage; D010102:Oxygen Inhalation Therapy / Q000295:instrumentation*
chemical_list: D010100:Oxygen