Comparison of 2 cuff inflation methods before insertion of laryngeal mask airway for safe use without cuff manometer in children

Efficacy and safety of three inflation methods of the laryngeal mask airway Ambu® Auraonce™: a randomized controlled study

The laryngeal mask airway (LMA) is commonly used for airway management. Cuff hyperinflation has been associated with complications, poor ventilation and increased risk of gastric insufflation. This study was designed to determine the best cuff inflation method of AuraOnce™ LMA during bronchoscopy and EBUS (Endobronquial Ultrasound Bronchoscopy) procedure. We designed a Randomized controlled, doble-blind, clinical trial to compare the efficacy and safety of three cuff inflation methods of AuraOnce™ LMA. 210 consenting patients scheduled for EBUS procedure under general anesthesia, using AuraOnce™ LMA were randomized into three groups depending on cuff insufflation: residual volume (RV), half of the maximum volume (MV), unchanged volume (NV). Parameters regarding intracuff pressure (IP), airway leak pressure (OLP), leakage volume (LV) were assessed, as well as postoperative complications (PC). 201 (95.7%) patients completed the study. Mean IP differed between groups (MV: 59.4 ± 32.4 cm H2O; RV: 75.1 ± 21.1 cm H2O; NV: 83.1 ± 25.5 cmH20; P < 0.01). The incidence of IP > 60 cmH2O was lower in the MV group compared to the other two (MV: 20/65(30.8%); RV:47/69 (68.1%); NV 48/67 (71.6%); p < 0.01). The insertion success rate was 89,6% (180/201) at first attempt, with no difference between groups (p = 0.38). No difference between groups was found either for OLP (p = 0.53), LV (p = 0.26) and PC (p = 0.16). When a cuff manometer is not available, a partial inflation of AuraOnce™ LMA cuff using MV method allows to control intracuff pressure, with no significant changes of OLP and LV compared to RV and NV insufflation method.Registration clinical trial: NCT04769791.

Incidence of postoperative sore throat after using a new technique of insertion of a second generation Laryngeal Mask Airway: A randomised controlled trial

BACKGROUND

Sore throat is a common complication after Laryngeal Mask Airway Supreme (SLMA) insertion.

OBJECTIVE

The aim of this study was to determine whether a new SLMA insertion technique (not removing the pilot tube blocker before insertion) lowers the incidence of sore throat in the postanaesthesia care unit (PACU).

DESIGN

A prospective, single-centre, parallel randomised controlled trial.

SETTING

Operating room and PACU at a hospital in China from June to September 2019.

PATIENTS

Four hundred and eight patients aged 18 to 65 years with American Society of Anaesthesiologists physical status class I or II who were scheduled for elective surgery requiring anaesthesia and SLMA insertion.

INTERVENTIONS

Leaving the blocker at the end of the pilot tube in situ (this blocker keeps the valve open and the balloon remains partially inflated but will deflate with pressure) or removing the blocker and actively deflating the cuff before SLMA insertion.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of postoperative sore throat in the PACU. The secondary outcomes included sore throat severity (Prince Henry Hospital Pain Score), first-attempt success rate, ease of insertion, time to successful SLMA insertion, oropharyngeal leak pressure, grade of view on fibreoptic bronchoscopy (indicating the accuracy of SLMA positioning) and adverse events.

RESULTS

The incidence of sore throat was 33/204 (16.2%) in the nonremoval group, and 65/204 (31.9%) in the removal group (P < 0.001). The first-attempt success rate was 174/204 (85.3%) in the nonremoval group and 150/204 (73.76%) in the removal group (P = 0.003; relative risk 1.160, 95% CI 1.049 to 1.282). The Kaplan--Meier curves showed that the insertion time in the nonremoval group was shorter (log-rank P = 0.01).

CONCLUSION

The new insertion technique, leaving the blocker attached to the end of the pilot balloon, resulted in a reduced incidence and severity of postoperative sore throat in the PACU, and an improved first-attempt success rate and the accuracy of SLMA positioning.

TRIAL REGISTRATION

Chinese Clinical Trial Registry identifier: ChiCTR1900023022.

A comparison of i-gel™ and Laryngeal Mask Airway Supreme™ during general anesthesia in infants

Background

The i-gel™ (i-gel) and Laryngeal Mask Airway Supreme™ (LMA Supreme) have been safely used in children. We compared the airway performance of the i-gel and LMA Supreme in infants undergoing general anesthesia.

Methods

Sixty infants with American Society of Anesthesiologists physical status I or II were randomly assigned to place either the i-gel or the LMA Supreme. The size 1 or 1.5 of each airway was selected by the weight of infants. The primary outcome variable was oropharyngeal leak pressure (OLP). We also assessed insertion success rate, insertion time, fiberoptic view of the larynx, airway quality, airway manipulations, and perioperative complications.

Results

Demographic data did not differ between the two groups. Insertion success rate was similar in both groups. OLP for the i-gel (26.0 ± 3.8 cmH₂O) was higher than for the LMA Supreme (23.7 ± 3.2 cmH₂O) (P = 0.016). Insertion time for the i-gel (16.4 ± 2.8 s) was shorter than for the LMA Supreme (18.5 ± 2.7 s) (P = 0.002). There were no differences in fiberoptic view of the larynx, airway quality, airway manipulations, and complications between the two groups.

Conclusions

This study demonstrated that the i-gel and LMA Supreme provided a similar performance of airway in infants. Compared with the LMA Supreme, the i-gel provided shorter insertion time and higher OLP in infants.

Comparison of the i-gel and other supraglottic airways in adult manikin studies: Systematic review and meta-analysis

BACKGROUND

The i-gel has a gel-like cuff composed of thermoplastic elastomer that does not require cuff inflation. As the elimination of cuff inflation may shorten insertion time, the i-gel might be a useful tool in emergency situations requiring prompt airway care. This systematic review and meta-analysis of previous adult manikin studies for inexperienced personnel was performed to compare the i-gel with other supraglottic airways.

METHODS

We searched PubMed, the Cochrane Library, and EMBASE for eligible randomized controlled trials (RCTs) published before June 2015, including with a crossover design, using the following search terms: "i-gel," "igel," "simulation," "manikin," "manikins," "mannequin," and "mannequins." The primary outcomes of this review were device insertion time and the first-attempt success rate of insertion.

RESULTS

A total of 14 RCTs were included. At the initial assessment without difficult circumstances, the i-gel had a significantly shorter insertion time than the LMA Classic, LMA Fastrach, LMA Proseal, LMA Unique, laryngeal tube, Combitube, and EasyTube. However, a faster insertion time of the i-gel was not observed in comparisons with the LMA Supreme, aura-i, and air-Q. In addition, the i-gel did not show the better results for the insertion success rate when compared to other devices.

CONCLUSION

The findings of this meta-analysis indicated that inexperienced volunteers placed the i-gel more rapidly than other supraglottic airways with the exception of the LMA Supreme, aura-i, and air-Q in manikin studies. However, the quicker insertion time is clinically not relevant. The unapparent advantage regarding the insertion success rate and the inherent limitations of the simulation setting indicated that additional evidence is necessary to confirm these advantages of the i-gel in an emergency setting.

The randomized crossover comparison of airway sealing with the laryngeal mask airway Supreme(™) at three different intracuff pressures in children

BACKGROUND

An intracuff pressure of 80 cm H2 O in the adult-sized laryngeal mask airway Supreme has been recommended to obtain a higher oropharyngeal leak pressure (OLP). However, the intracuff pressure for the higher OLP in the pediatric laryngeal mask airway Supreme could be different from that in the adult-sized laryngeal mask airway Supreme. Thus, we measured and compared OLP at three intracuff pressures of 40, 60, and 80 cm H2 O in the pediatric laryngeal mask airway Supreme.

METHODS

This study was designed as a randomized crossover study and enrolled 36 children, aged 0-108 months and 5-30 kg in weight. After insertion of the laryngeal mask airway Supreme, oropharyngeal leak pressure (OLP) was measured at intracuff pressures of 40, 60, and 80 cm H2 O according to one of six sequences produced on the basis of 3 × 6 Williams crossover design. During the intraoperative period, the laryngeal mask airway Supreme was maintained using the last intracuff pressure of the allocated sequence. The intraoperative and postoperative complications were compared among three maintenance intracuff pressures.

RESULTS

OLP at the intracuff pressure of 60 cm H2 O was significantly higher than that of 40 cm H2 O (17.9 ± 3.9 vs 16.9 ± 4.2 cm H2 O, P = 0.004) and was comparable with that of 80 cm H2 O (17.9 ± 3.9 vs 17.8 ± 4.6 cm H2 O, P = 0.938). There were no significant differences of intraoperative and postoperative complications among the three maintenance intracuff pressures.

CONCLUSION

Our results suggest that the use of an intracuff pressure of 60 cm H2 O in pediatric laryngeal mask airway Supreme provides a higher OLP compared with 40 cm H2 O.