Comparison of standard versus 90° rotation technique for LMA Flexible™ insertion: a randomized controlled trial

Abstract

Background Insertion of a flexible laryngeal mask airway (LMA Flexible) is known to be more difficult than that of a conventional laryngeal mask airway. The 90° rotation technique can improve the success rate with a conventional laryngeal mask airway but its effect with the LMA Flexible remains unknown. We assessed whether the 90° rotation technique increased the first-attempt success rate of LMA Flexible insertion versus the standard technique. Methods In total, 129 female patients undergoing breast surgery were analyzed. The primary endpoint was success at the first attempt. The insertion time, number of trials, number of manipulations required, and oropharyngeal leak pressure were also evaluated. Heart rate and mean blood pressure were recorded 1 min before and 1 min after insertion. Blood staining on the LMA Flexible after removal and postoperative sore throat were checked. Results The first-attempt success rates were comparable between the groups (93% vs. 98.3%, P = .20). The insertion time, number of trials and manipulations, hemodynamic variables, and complications, such as blood staining and sore throat, did not differ between the groups. Conclusions The 90° rotation technique is a good alternative to the standard technique for insertion of the LMA Flexible. Trial registration ClinicalTrials.gov ( NCT03028896 ). It was registered retrospectively at Jan 19th, 2017.

Standard digit-based versus 90° rotation technique for supraglottic airway device insertion: a meta-analysis of randomized controlled trials

“…Therefore, 10 RCTs, with 1286 patients, were included in the final meta-analysis (Fig. 1) [7,8,[11][12][13][21][22][23][24][25]. In the study selection, kappa value between two authors was 0.811, indicating excellent agreement.…”

“…The Proseal TM LMA device was used in half of the included RCTs [7,8,12,22,24] and the i-gel TM device was used in 2 RCTs [21,25]. The Classic TM , Unique TM , and Flexible TM LMA devices were placed in the remaining RCTs [11,13,23]. In 6 RCTs, the SGA cuff was fully deflated before insertion and was inflated after placement [7,8,[11][12][13]24].…”

“…The Classic TM , Unique TM , and Flexible TM LMA devices were placed in the remaining RCTs [11,13,23]. In 6 RCTs, the SGA cuff was fully deflated before insertion and was inflated after placement [7,8,[11][12][13]24]. The cuff was partially inflated before insertion in another 2 RCTs [22,23].…”

“…The remaining 2 RCTs employed the i-gel TM , which has no cuff [21,25]. In 6 RCTs, authors performed manipulations, including chin lift, jaw thrust, head extension, neck flexion, or movement of the SGA device for device placement, if needed [7,11,13,21,24,25]. NMBAs were administered before SGA device insertion in 7 RCTs [8,[11][12][13]21,24,25], whereas no NMBA was used in 3 RCTs [7,22,23].…”

“…Among these approaches, the 90° rotation technique was first introduced by Hwang et al in 2009 [7]. Thereafter, this technique has been investigated with a variety of SGA devices in several studies [8,11,12,13]. The 90° rotation technique has shown favorable results in increasing the success rate of SGA device insertion in several studies [8,12].…”