title: The rate of sulfur hexafluoride escape from a plastic syringe.
abstract: Sulfur hexafluoride (SF6) gas is widely used for internal tamponade during retinal reattachment surgery and is commonly injected into the eye from a 10-mL plastic syringe. The rate of diffusion of SF6 out of a plastic syringe has not bee studied. We measured the percentage of SF6 gas in a 10-mL plastic syringe by gas chromatography, confirmed by infrared spectrometry. Measurements were obtained immediately after aspiration, and at 30 s and 10, 15, 60, 90, and 120 minutes, and 18 hours. A marked decrease in SF6 concentration, from 97% at 30 s to 76% at 60 minutes and 2% at 18 hours, was noted. The results were highly reproducible. Sulfur hexafluoride gas should be injected into the patient's eye as soon as possible after aspiration from the tank to ensure accurate concentrations.
authors.affiliation: Wilmer Ophthalmological Institute, Johns Hopkins Hospital, Baltimore, MD 21205.
authors.forename: M S
authors.initials: MS
authors.lastname: Humayun
authors.forename: J H
authors.initials: JH
authors.lastname: Yeo
authors.forename: W S
authors.initials: WS
authors.lastname: Koski
authors.forename: R G
authors.initials: RG
authors.lastname: Michels
mesh_terms: D002849:Chromatography, Gas; D004058:Diffusion; D005459:Fluorides / Q000032:analysis*; D005740:Gases; D010969:Plastics; D013055:Spectrophotometry, Infrared; D013459:Sulfur Hexafluoride / Q000032:analysis*; D013594:Syringes; D013997:Time Factors
chemical_list: D005740:Gases; D010969:Plastics; D005459:Fluorides; D013459:Sulfur Hexafluoride