title: [The cracks of polycarbonate three-way stopcocks are enhanced by the lubricating action of fat emulsion of propofol].
abstract: The possible mechanism of cracks in the polycarbonate three-way stopcocks was investigated in the presence of propofol. We compared the crack formations with various insertion force and contact surface conditions. We could successfully reproduce overt cracks with leakage in three-way stopcocks when the male adaptors were strongly inserted and the contact surface was damped with propofol. With normal strength, no overt crack was observed at any liquid contact conditions. The male connector is more deeply inserted into the female three-way stopcock at the same insertion force when contact surface is damped with propofol. When propofol is present, the release force is not enhanced further while insertion force is increased. We conclude that the cracks in three-way stopcocks are enhanced by the increased expansion force by the lubricating action of propofol fat emulsion.
authors.affiliation: Department of Anesthesiology and Pain Control, Chuden Hospital, Hiroshima 730-8562.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Nakao
authors.forename: Shuichi
authors.initials: S
authors.lastname: Yamanaka
authors.forename: Minoru
authors.initials: M
authors.lastname: Iwata
authors.forename: Masakuni
authors.initials: M
authors.lastname: Nakashima
authors.forename: Izumi
authors.initials: I
authors.lastname: Onji
mesh_terms: D000771:Anesthesia, Intravenous / Q000295:instrumentation*; D004868:Equipment Failure; D005217:Fat Emulsions, Intravenous / Q000009:adverse effects*; D008153:Lubrication; D011108:Polymers; D015742:Propofol / Q000009:adverse effects*; D013314:Stress, Mechanical
chemical_list: D005217:Fat Emulsions, Intravenous; D011108:Polymers; C017902:lexan; D015742:Propofol