Randomized Evaluation of the Single-use SoftSeal^™ and the Re-useable LMA Classic^™ Laryngeal Mask

Abstract

A number of laryngeal masks are available, including both re-usable and single-use masks. Single-use laryngeal masks may decrease the risk of transmitting prion infections. We performed a single-blind randomized trial in 200 spontaneously breathing female patients under general anaesthesia with nitrous oxide, to compare a new single-use laryngeal mask, the SoftSeal™ (Portex Ltd, U.K.), with a re-usable laryngeal mask, the LMA Classic™ (Laryngeal Mask Company Ltd., Cyprus). The primary outcome was successful insertion at the first attempt. Size 4 single-use (n=99) or re-usable (n=100) laryngeal masks, inserted by experienced anaesthetists, were equivalent for successful placement at the first attempt (90% versus 91% respectively). The single-use mask was less easy to insert (47% difficult versus 9%, P<0.001). Clinical and anatomical tests of position and function were similar. The cuff pressure of the re-usable mask increased significantly compared with the single-use mask (median +10 cm versus-2 cm H 2 O, P<0.001). Forty per cent of patients allocated the single-use mask and 20% of those allocated the re-usable mask experienced sore throat at 24 hours postoperatively (P<0.05). An estimation of cost per patient use was greater for the re-usable mask. We conclude that the SoftSeal™ single-use laryngeal mask and the LMA Classic™ re-usable laryngeal mask airway are of similar clinical utility in terms of successful insertion and airway maintenance. The re-usable laryngeal mask was easier to insert and associated with less postoperative sore throat, but costs were higher.

A clinical evaluation of four disposable laryngeal masks in adult patients

“…However, this potential advantage had no clinical implication because it did not result in improved ventilation in this group and airway pressure was easily maintained below sealing pressure in all patients. Our results are in agreement with those of Paech et al [13], Tan et al [21], Cook et al [18], and Francksen et al [22], who reported a better airway seal with the Soft Seal than the LMA Unique. In contrast, Brimacombe et al [16] found no differences in leak pressure between the Soft Seal and the LMA Unique in paralyzed patients.…”

“…In most cases, the presence of blood was minimal and did not correlate with pain during recovery. Paech et al [13], Cook et al [18], and Tan et al [21] found a similar frequency of mucosal trauma with the Soft Seal. However, van Zundert et al [12] reported macroscopic blood in only 4% of laryngeal mask uses, all from the LMA Classic group.…”

“…In previous studies, a higher incidence of sore throat corresponding to higher mucosal trauma with the Soft Seal was reported in comparison with the LMA Unique [18,21] or LMA Classic [13]. van Zundert et al [23] found a low frequency of airway morbidity with the Soft Seal, LMA Unique, and CobraPLA in spite of greater blood staining with the CobraPLA.…”

“…3). Some studies have assessed its clinical performance compared with that of the LMA Classic [12][13][14][15] and the LMA Unique [16][17][18], with varying results. The Solus has the same sizes and design as the LMA Unique, except without epiglottic bars (Solus Laryngeal Mask Airway information sheet; Intersurgical, Ltd), but it has a harder cuff.…”

Securing the prehospital airway: a comparison of laryngeal mask insertion and endotracheal intubation by UK paramedics

“…The disposable laryngeal mask avoids this cross infection risk, particularly in relation to prion transmission. 25 Although there are numerous manikin studies comparing laryngeal mask insertion or endotracheal intubation, there is a need for more quantitative clinical studies comparing the two devices. We therefore designed a study to compare the time taken to secure the airway using laryngeal mask insertion and endotracheal intubation in patients undergoing elective surgical procedures to assess whether any difference exists between the two devices.…”