Randomized comparison of the i-gel™, the LMA Supreme™, and the Laryngeal Tube Suction-D using clinical and fibreoptic assessments in elective patients

Abstract

Background: The i-gel™, LMA-Supreme (LMA-S) and Laryngeal Tube Suction-D (LTS-D) are single-use supraglottic airway devices with an inbuilt drainage channel. We compared them with regard to their position in situ as well as to clinical performance data during elective surgery.

Methods: Prospective, randomized, comparative study of three groups of 40 elective surgical patients each. Speed of insertion and success rates, leak pressures (LP) at different cuff pressures, dynamic airway compliance, and signs of postoperative airway morbidity were recorded. Fibreoptic evaluation was used to determine the devices' position in situ.

Results: Leak pressures were similar (i-gel™ 25.9, LMA-S 27.1, LTS-D 24.0 cmH2O; the latter two at 60 cmH2O cuff pressure) as were insertion times (i-gel™ 10, LMA-S 11, LTS-D 14 sec). LP of the LMA-S was higher than that of the LTS-D at lower cuff pressures (p <0.05). Insertion success rates differed significantly: i-gel™ 95%, LMA-S 95%, LTS-D 70% (p <0.05). The fibreoptically assessed position was more frequently suboptimal with the LTS-D but this was not associated with impaired ventilation. Dynamic airway compliance was highest with the i-gel™ and lowest with the LTS-D (p <0.05). Airway morbidity was more pronounced with the LTS-D (p <0.01).

Conclusion: All devices were suitable for ventilating the patients' lungs during elective surgery.

Trial registration: German Clinical Trial Register DRKS00000760.

Figure 1

Flow chart of the study, showing the subdivision into groups corresponding to each supraglottic airway device. 1st or 2nd success = insertion success rate for the first or the second insertion attempt. i-gel™; LMA-S = LMA-Supreme™; LTS-D = Laryngeal Tube Suction-D; TT = tracheal tube.

Figure 2

Leak pressure (LP) versus cuff pressure shown for the i-gel™, the LMA-Supreme™ and the Laryngeal Tube Suction-D. LP is given in cmH₂0. The grey circle represents the i-gel™, white circles represent the LMA-S, black circles represent the LTS-D.

Figure 3

Flow chart indicating the number of failures and the supraglottic airway device used as the secondary device, including the corresponding success rates. 1st or 2nd success = insertion success rate for the first or the second insertion attempt. i-gel™; LMA-S = LMA-Supreme™; LTS-D = Laryngeal Tube Suction-D; TT = tracheal tube. Below the horizontal line is the summary for each device (intention-to-treat plus rescue device).

Figure 4

Examples of fibrescopic images. A) i-gel™, note that the epiglottis does not rest on the epiglottis rest outside the mask bowl; B) LMA-Supreme™, note the narrowing of the vocal cords; C and D) Example of awkward position in situ of the Laryngeal Tube Suction-D, ventilation was possible in both examples. 1 = glottic inlet, 2 = arytenoids.