Comparison of the Re-usable LMA Classic^™ and Two Single-use Laryngeal Masks (LMA Unique^™ and SoftSeal^™) in Airway Management by Novice Personnel

Abstract

In a single-blind randomized trial, three types of laryngeal masks: the reusable LMA Classic™, the single-use LMA Unique™ and SoftSeal™ were inserted by novice medical officers in anaesthesia. Five successive attempts were undertaken with each mask type. The order of the mask type insertion was randomly selected. Mean (SD) insertion times for LMA Classic™, LMA Unique™ and Soft Seal™ were 32.9 (12.3), 39.6 (23.4) and 49.4 (50.4) seconds respectively. Differences were only significant between LMA Classic™ and SoftSeal™ (P=0.012). There were no significant differences in first attempt success rates (LMA Classic™ 80%, LMA Unique™ 77% and SoftSeal™ 62%). The SoftSeal™ was most frequently associated with blood on the mask (32%) compared to the LMA Unique™ (9%) and LMA Classic™ (6%). Sore throat was experienced in 14% of patients in the LMA Unique™ group versus 41% and 42% in the LMA Classic™ and SoftSeal™ groups respectively. Mean±SD oropharyngeal leak pressure was significantly higher in the SoftSeal™ (21±6 cmH 2 O) compared to the LMA Classic™ (17±7 cmH 2 O) and LMA Unique™ (16±6 cmH 2 O). Novice medical doctors can be taught to insert disposable laryngeal masks. The SoftSeal™ took longer to insert, which resulted in a higher incidence of blood on the mask, but success rates did not differ. The LMA Unique™ was associated with the lowest incidence of sore throat in the immediate postoperative period. A higher oropharyngeal leak pressure with the SoftSeal™ may indicate improved airway seal and protection against aspiration.

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.…”

“…Although differences among studies in the definition of insertion time do not permit easy comparison, the longer insertion time in our study compared with that from other studies performed by expert users reflects more attempts and more time per attempt, as is to be expected from operators with little experience [20,21]. We found no significant differences in insertion time among the device groups, but the Ambu LM had the shortest insertion time, probably owing to its curved shape.…”

“…In contrast, van Zundert et al [23] found no differences between the LMA Unique and Soft Seal when compared with the CobraPLA. In another study, it was the Soft Seal (not the LMA Unique) that required more time to be placed by novice personnel than the LMA Classic [21]. Insertion of the Soft Seal with the cuff fully deflated, as was done in this study, seems to be more difficult and traumatic for the patient [23], which is a potential bias against this device.…”

Comparison of Laryngeal Mask Supreme® and Soft Seal® for airway management in several positions

“…LMAs are recommended by professionals for airway rescue in failed intubation [15]. Older models, such as the LMA-Classic Ò , LMA-ProSeal Ò , or Soft Seal have been shown to rescue the airway in a quick and safe fashion.…”

Comparison of Supreme® and Soft Seal® laryngeal masks for airway management during cardiopulmonary resuscitation in novice doctors: a manikin study

“…Thus, we compared the performance of the Supreme and the conventional Soft Seal Ò LMA (Smiths Medical, USA) during chest compression with a manikin [6].…”