Case Series of Inappropriate Concentration of Intraocular Sulfur Hexafluoride

Abstract

Due to high complexity, vitreoretinal surgery presents a higher number of patient safety incidents compared with other ophthalmic procedures. Intraocular gases are one of the most useful adjuncts to vitrectomy and surprisingly, surgeons commonly admit to having occasional problems with incorrect gas concentration. The aim of this study is to present a consecutive case series of patients with improper concentration of sulfur hexafluoride (SF₆) applied during vitrectomy. Three patients underwent 27-gauge vitrectomy and at the end of surgery inappropriate dilution of 100% SF₆ was administered. It was attributed to a calculation error, change in the gas supplier, or increased partial pressure of SF₆ before dilution. Postoperatively, due to IOP increase, two eyes required intravitreal gas-air exchange. Subsequently, cataract surgery was performed in one eye with concomitant vitrectomy and silicone oil tamponade due to retinal detachment. To prevent such complications, we suggest using intraocular gases with great care, training of ophthalmic personnel, and prompting manufacturers to provide SF₆ in a prepared concentration of 20%.

Complications Associated with the Use of Expandable Gases in Vitrectomy

“…In practice, the final concentration used during vitrectomy is at the surgeon's discretion [14]. Interestingly, vitreoretinal surgeons commonly admit to having problems with incorrect gas concentration, and postsurgical IOP elevation is associated with high gas concentrations [35]. Other risk factors include advanced patient age and concomitant circumferential scleral buckling [28, 32].…”

Comments on: Internal Limiting Membrane Peeling and Gas Tamponade for Full-Thickness Macular Holes of Different Etiology – Is It Still Relevant? [Response to Letter]

“… 1 , 2 Postsurgical IOP elevation is associated with high gas concentrations, which is determined by the amount, type of injected gas and the vitreous chamber volume (VCV). 3 Therefore, knowledge of the exact volume of the vitreous cavity is extremely important for the prevention of such complications.…”

Orbital Gas after 25-Gauge Pars Plana Vitrectomy with Incorrect Gas Mixture

“…Incorrect concentration of diluted gas is generally thought to be related to a suspected error in gas mixture or the presence of highly soluble nitrous oxide-based anesthesia allowing for rapid gas expansion of the gas/air mixture. Retrobulbar gas is rare in the era of microincisional vitrectomy but can occur in the setting of incomplete sclerotomy closures [8]. Potential complications of expandable gases include increased intraocular pressure (IOP), vision loss, and orbital compartment syndrome [9].…”