Head elevation and laryngeal mask airway Supreme insertion: A randomized controlled trial

How does head position affect laryngeal vision with a video laryngeal mask airway?

Background

The Laryngeal Mask Airway Vision Mask (LMA VM) is a supraglottic airway device (SAD) with a vision guidance system. The ideal head and neck position for direct laryngoscopy is known, but the ideal position for placing a LMA is not. The objective of this study is to evaluate and compare the optimal position for placement of a video laryngeal mask airway.

Methods

This prospective, observational, transversal, and analytical study was performed in 72 consecutive patients. In the same patient, laryngeal vision was first assessed with the head and neck in the sniffing position and then with the head in the neutral position. Procedures were performed by the same investigator. The assessment of the laryngeal view was performed using two classifications: Cormack-Lehane classification and Brimacombe classification. The placement of the device was considered adequate when the Cormack-Lehane rating was between 1 and 2 and the Brimacombe rating between 2 and 4.

Results

In this study, 72 patients participated. In the assessment of the glottis using the Cormack-Lehane classification for fibre-optic view, laryngeal visibility was adequate in 64 (88.89%) patients in the neutral position and in 65 (90, 28%) patients in the sniffing position (p > 0.05). In the fibre-optic view of the glottis, evaluated using the Brimacombe classification, laryngeal visibility was adequate in 68 (93%) patients in the neutral position and in 69 (95%) patients in the sniffing position (p > 0.05). There was no statistically significant difference in the rate of success between the sniffing position (70 patients, 97.22% success rate) and the neutral position (67 patients, 93.06% success rate) during the first insertion attempt. Two patients required a second attempt in the sniffing position, while five patients required a second attempt in the neutral position.

Conclusion

An adequate sniffing position did not result in a better glottic view than the neutral position. Additional manoeuvres were equal in both positions. The head-neck position does not influence on the placement of a third-generation SAD.

Effect of the new video laryngeal mask airway SaCoVLM on airway management in lateral laparoscopic urological surgery: A single center randomized controlled trial

There are few pertinent studies about the application of laryngeal mask airways (LMAs) in lateral decubitus surgery. Therefore, the aim of our study was to evaluate the effects of lateral position and pneumoperitoneum on oropharyngeal leak pressure (OLP) and ventilation efficiency for the LMA SaCoVLM. Patients undergoing elective retroperitoneal laparoscopic urological surgery were randomized 1:1 to the Supreme group or SaCoVLM group. The primary outcome was the OLP with LMA insertion. The secondary outcomes were the first-attempt success rate, insertion time, adjustment times, gastric tube success rate, LMA alignment accuracy, LMA removal time, regurgitation or aspiration, LMA blood staining, and incidence of adverse events 24 h after surgery. We recruited 70 patients to complete the study. Regardless of lateral position and pneumoperitoneum, the OLP was greater in the SaCoVLM group (n = 35) than in the Supreme group (n = 35), with a median difference of 4-7 cmH2O. The first-attempt success rate of the SaCoVLM group was higher than that of the Supreme group (91.4% vs. 77.1%, risk ratio (RR): 1.19; 95% CI 0.96 to 1.46, P = 0.188). Thus, in the lateral position with pneumoperitoneum, although the new video LMA SaCoVLM has a higher OLP than the LMA Supreme, both devices provide sufficient ventilation efficiency.

Supraglottic Airway Devices with Vision Guided Systems: Third Generation of Supraglottic Airway Devices

Supraglottic airway devices are currently widely used for airway management both for anaesthesia and emergency medicine. First-generation SADs only had a ventilation channel and did not provide protection from possible aspiration of gastric content if regurgitation occurred. Second-generation SADs are equipped with a gastric channel to allow the insertion of a gastric catheter and suctioning of gastric content. Additionally, the seal was improved by a change in the shape of the cuff. Some second-generation SADs were also designed to allow for intubation through the lumen using fiberscopes. Although the safety and efficacy of use of SADs are very high, there are still some issues in terms of providing an adequate seal and protection from possible complications related to misplacement of SAD. New SADs which allow users to choose the insertion scope and control the position of SAD can overcome those problems. Additionally, the Video Laryngeal Mask Airway may serve as an endotracheal intubation device, offering a good alternative to fibre-optic intubation through second-generation SADs. In this narrative review, we provide knowledge of the use of video laryngeal mask airways and the possible advantages of introducing them into daily clinical practice.

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

BACKGROUND

Prompt insertion and placement of supraglottic airway (SGA) devices in the correct position are required to secure the airway. This meta-analysis was performed to validate the usefulness of the 90° rotation technique as compared with the standard digit-based technique for the insertion of SGA devices in anesthetized patients in terms of insertion success rate, insertion time, and postoperative complications.

METHODS

A literature search of PubMed, EMBASE, CENTRAL, CINAHL, Scopus, and Web of Science was conducted. Randomized controlled trials, without limitations on publication period, language, journal, or region, until July 2021, that compared the 90° rotation and the standard digit-based techniques for insertion of SGA devices in anesthetized patients were included.

RESULTS

The first-attempt (risk ratio [RR]: 1.16, 95% CI [1.09, 1.25], P < 0.001) and overall success rates (RR: 1.06, 95% CI [1.03, 1.09], P < 0.001) were significantly higher in the 90° rotation group. The insertion time was shorter in the 90° rotation group (mean difference: -4.42 s, 95% CI [-6.70, -2.15 s], P < 0.001). The incidences of postoperative sore throat (RR: 0.63, 95% CI [0.49, 0.83], P < 0.001) and blood staining (RR: 0.28, 95% CI [0.20, 0.39], P < 0.001) were lower in the 90° rotation group.

CONCLUSIONS

The use of the 90° rotation technique increases the success rate of SGA device insertion and decreases postoperative complications as compared with that of the standard digit-based technique in anesthetized patients.

Preliminary evaluation of SaCoVLM™ video laryngeal mask airway in airway management for general anesthesia

Background

To preliminary evaluate the application of SaCoVLM™ video laryngeal mask airway in airway management of general anesthesia.

Methods

We recruited 100 adult patients (ages 18–78 years, male 19, female 81, weight 48–90 kg) with normal predicted airway (Mallampati I ~ II, unrestricted mouth opening, normal head and neck mobility) and ASA I-II who required general anaesthesia. The SaCoVLM™ was inserted after anesthesia induction and connected with the anesthesia machine for ventilation. Our primary outcome was glottic visualization grades. Secondary outcomes included seal pressure, success rate of insertion, intraoperative findings (gastric reflux and contraposition), gastric drainage and 24-h complications after operation.

Results

The laryngeal inlet was exposed in all the patients and shown on the video after SaCoVLM™ insertion. The status of glottic visualization was classified: grade 1 in 55 cases, grade 2 in 23 cases, grade 3 in 14 cases and grade 4 in 8 cases. The first-time success rate of SaCoVLM™ insertion was 95% (95% CI = 0.887 to 0.984), and the total success rate was 96% (95% CI = 0.901 to 0.989). The sealing pressure of SaCoVLM™ was 34.1 ± 6.2 cmH₂O and the gastric drainage were smooth. Only a small number of patients developed mild complications after SaCoVLM™ was removed (such as blood stains on SaCoVLM™ and sore throat).

Conclusions

The SaCoVLM™ can visualize partial or whole laryngeal inlets during the surgery, with a high success rate, a high sealing pressure and smooth gastroesophageal drainage. SaCoVLM™ could be a promise new effective supraglottic device to airway management during general anesthesia.

Trial registration

ChiCTR,ChiCTR2000028802.Registered 4 January 2020.