A clinical evaluation of four disposable laryngeal masks in adult patients

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.

Comparison of the clinical performance of i-gel and Ambu laryngeal masks in anaesthetised paediatric patients: A meta-analysis

BACKGROUND

Paediatric supraglottic airway devices (SGAs) are widely used in routine anaesthesia and serve as primary or back-up devices for difficult airway management. The inflatable Ambu laryngeal masks and non-inflatable i-gel are two improvements of SGAs based on classic laryngeal masks. The clinical performance and safety of these two devices in paediatric patients are still unclear and warrant further investigation.

AIM

To perform a systematic review and meta-analysis on the clinical performance and safety of Ambu laryngeal masks and i-gel in anaesthetised paediatric patients.

METHODS

MEDLINE, Embase, Web of Science and Cochrane Central Register of Controlled Trials were searched from inception dates to April 2020. We identified published randomised controlled trials (RCTs) in which the intervention involved the use of Ambu laryngeal masks and i-gel in anaesthetised paediatric patients (age < 18 years). We assessed the oropharyngeal leak pressure (OLP) as the primary outcome. The secondary outcomes were insertion time, success rate of insertion on the first attempt, and incidence of adverse events.

RESULTS

After searching for all relevant trials published up to April 2020, data from seven RCTs with a total of 667 paediatric patients (323 and 344 participants in the i-gel and Ambu groups, respectively) were evaluated. The mean OLP in anaesthetised paediatric patients was lower in the Ambu group [21.82 cmH₂O for Ambu vs 23.98 cmH₂O for i-gel, P = 0.003, 95% confidence interval (CI): -3.58 to -0.75, I² = 68%, Mantel-Haenszel random model]. We did not find any clear evidence of differences between the devices in terms of insertion time, success rate of insertion, and incidence of adverse events except for blood staining (risk ratio 5.86, 95%CI: 1.76 to 19.46, P = 0.004, I² = 0, fixed-effect model).

CONCLUSION

The i-gel airway may provide a better seal and is therefore probably more suitable than the Ambu laryngeal mask airway in anaesthetised paediatric patients. However, the evidence is insufficient to allow making firm conclusions or to guide clinical practice, owing to the small number of relevant published studies.

Incidence of gastric insufflation at high compared with low laryngeal mask cuff pressure: A randomised controlled cross-over trial

BACKGROUND

The success of ventilation with a laryngeal mask depends crucially on the seal between the mask and the periglottic tissue. Increasing the laryngeal mask's cuff volume is known to reduce oral air leakage but may lead to gastric insufflation.

OBJECTIVE

We hypothesised that a lower cuff pressure would result in less gastric insufflation. We sought to compare gastric insufflation with laryngeal mask cuff pressures of 20 cmH2O (CP20) and 60 cmH2O (CP60) during increasing peak airway pressures in a randomised controlled double-blind cross-over study. We also evaluated the incidence of gastric insufflation at the recommended peak airway pressure of 20 cmH2O or less and during both intermittent positive airway pressure and continuous positive airway pressure.

METHODS

After obtaining ethics approval and written informed consent, 184 patients ventilated via laryngeal mask received a stepwise increase in peak airway pressure from 15 to 30 cmH2O with CP20 and CP60 in turn. Gastric insufflation was determined via real-time ultrasound and measurement of the cross-sectional area of the gastric antrum. The primary endpoint was the incidence of gastric insufflation at the different laryngeal mask cuff pressures.

RESULTS

Data from 164 patients were analysed. Gastric insufflation occurred less frequently at CP20 compared with CP60 (P < 0.0001). Gastric insufflation was detected in 35% of cases with CP20 and in 48% with CP60 at a peak airway pressure of 20 cmH2O or less. Gastric insufflation occurred more often during continuous than during intermittent positive airway pressures (P < 0.01).

CONCLUSION

A laryngeal mask cuff pressure of 20 cmH2O may reduce the risk of gastric insufflation during mechanical ventilation. Surprisingly, peak airway pressure of 20 cmH2O or less may already induce significant gastric insufflation. Continuous positive airway pressure should be avoided due to an increased risk of gastric insufflation.

CLINICAL TRIAL REGISTRATION

The study was registered in the German Clinical Trials Register (DRKS00010583) https://www.drks.de.

Comparative study of the Ambu® AuraOnce™ laryngeal mask and endotracheal intubation in anesthesia airway management during neurosurgery

Objective

To investigate the feasibility and efficacy of the Ambu® AuraOnce™ laryngeal mask (LMA) compared with endotracheal intubation (ETI) during supratentorial tumor resection in the right lateral decubitus position.

Methods

This was a randomized controlled trial of LMA compared with ETI in patients who were scheduled to undergo supratentorial tumor resection in the right lateral decubitus position. The patients were randomized to the LMA (n = 40) and ETI groups (n = 40). The hemodynamic parameters (primary outcome) and mechanical ventilation parameters, anesthetic dose, and complications as well as quality of anesthesia recovery (secondary outcomes) were compared.

Results

Patients in the LMA group exhibited lower mean arterial pressure (MAP) and heart rate (HR) compared with ETI. Nine and two patients received esmolol during intubation and extubation, respectively. The airway pressure (AP) in the LMA group was higher compared with the ETI group 60 minutes after the start of surgery. Compared with the ETI group, the sufentanil dose was lower by 24% and the anesthesia recovery rate was better in the LMA group.

Conclusions

LMA can improve hemodynamic stability in patients undergoing supratentorial tumor resection in the right lateral decubitus position. If there is a clinical need and no contraindication, LMA could replace ETI.

Ambu AuraOnce versus i-gel laryngeal mask airway in infants and children undergoing surgical procedures. A randomized controlled trial

Objectives:

To compare the efficacy and performance of the pediatric Ambu AuraOnce (Ambu AO) mask (Ambu, Copenhagen, Denmark) and i-gel mask (Intersurgical Ltd., Wokingham, United Kingdom).

Methods:

From May 2015 to September 2016, 112 patients, 0-14 years old, underwent elective surgery at a tertiary university hospital (Riyadh, Saudi Arabia). They were randomly assigned to the Ambu AO or i-gel group. Three groups underwent a subgroup analysis: ≤5 kg (group 1), 5.1–10.0 kg (group 2), and >10 kg (group 3).

Results:

The oropharyngeal leak pressure was significantly higher for the i-gel (25.4±4.1 cm H₂O) than for the Ambu AO (22.5±3.9 cm H₂O, p<0.001). The Ambu AO had a slightly higher ease of insertion compared to the i-gel (100% versus 94%, p=0.08) and required less manipulation (2% versus 11%, p=0.07).The Ambu AO and i-gel showed non-significant differences in performance between weight groups. There were statistically significant differences for higher leak pressure in group 2 (p=0.01) and group 3 (p=0.002) in favor of the i-gel, and for less manipulation in the Ambu AO in group 1 (p=0.04). Fiberoptic viewing was superior in group 2 for the i-gel (p=0.03) and in group 3 for the Ambu AO (p=0.02).

Conclusion:

Both devices demonstrated equally good performance with low morbidity. The Ambu AO had a statistical tendency towards easier insertion and less manipulation. Confirming this finding will require large scale trials.

[Comparison of three different insertion techniques with LMA-Unique™ in adults: results of a randomized trial]

BACKGROUND

The triple airway maneuver insertion technique allowed faster insertion of the LMA. This study compared three different insertion techniques of the laryngeal mask airway-Unique™.

METHODS

One hundred and eighty ASA I-II patients aged 18-65 years were included into the study. Patients were randomly allocated to the standard, rotational and triple airway maneuver (triple) group. In the standard group (n=60), the LMA (Laryngeal Mask Airway) was inserted with digital intraoral manipulation. In the triple group (n=60), the LMA was inserted with triple airway maneuver (mouth opening, head extension and jaw thrust). In the rotational group (n=60), LMA was inserted back-to-front, like a Guedel airway. Successful insertion at first attempt, time for successful insertion, fiber optic assessment, airway morbidity and hemodynamic responses were assessed.

RESULTS

Successful insertion at the first attempt was 88.3% for the standard, 78.3% for the rotational and 88.3% for the triple group. Overall success rate (defined as successful insertion at first and second attempt) was 93% for the standard, 90% for the rotational and 95% for the triple group. Time for successful insertion was significantly shorter in the triple group (mean [range] 8.63 [5-19]s) compared with the standard (11.78 [6-24]s) and rotational group (11.57 [5-31]s). Fiber optic assessment, airway morbidity and hemodynamic responses were similar in all groups.

CONCLUSIONS

Rotational and triple airway maneuver insertion techniques are acceptable alternatives. Triple airway maneuver technique shows higher overall success rates and allows shorter insertion time for LMA insertion and should therefore be kept in mind for emergent situations.

Comparison of classic laryngeal mask airway with Ambu laryngeal mask for tracheal tube exchange: A prospective randomized controlled study

Background and Aim:

Exchanging endotracheal tube (ETT) with classic laryngeal mask airway™ (CLMA™) prior to emergence from anaesthesia is a safe technique to prevent the coughing and haemodynamic changes during extubation. We had compared CLMA™ and AMBU laryngeal mask™ (ALM™) during ETT/laryngeal mask (LM) for haemodynamic changes and other parameters.

Methods:

A total of 100 American Society of Anesthesiologist Grade I and II adult female patients undergoing elective laparoscopic cholecystectomy under general anaesthesia were selected and randomly divided into two groups of 50 patients each. In Group I, CLMA™ and in Group II, ALM™ was placed prior to tracheal extubation. Haemodynamic parameters were recorded during ETT/LM exchange. Glottic view was seen through the LM using flexible fibrescope. Coughing/bucking during removal of LM, ease of placement and post-operative sore throat for both groups were graded and recorded.

Statistical Analysis:

Data within the groups was analysed using paired t-test while between the groups was analysed using unpaired t-test. Chi-square test was used to analyse grades of glottic view, coughing, and post-operative sore throat.

Results:

In Group I, there was a significant rise in systolic blood pressure and heart rate in contrast to insignificant rise in Group II. Glottis view was significantly better in Group II. Incidence of coughing, ease of placement and post-operative sore throat was identical between both groups.

Conclusion:

ALM™ is superior to CLMA™ for exchange of ETT before extubation due to greater haemodynamic stability during exchange phase and is better positioned.

Randomised Comparison of the AMBU AuraOnce Laryngeal Mask and the LMA Unique Laryngeal Mask Airway in Spontaneously Breathing Adults

We conducted a randomised single-blind controlled trial comparing the LMA-Unique (LMAU) and the AMBU AuraOnce (AMBU) disposable laryngeal mask in spontaneously breathing adult patients undergoing general anaesthesia. Eighty-two adult patients (ASA status I–IV) were randomly allocated to receive the LMAU or AMBU and were blinded to device selection. Patients received a standardized anesthetic and all airway devices were inserted by trained anaesthetists. Size selection was guided by manufacturer recommendations. All data were collected by a single, unblinded observer. When compared with the LMAU, the AMBU produced significantly higher airway sealing pressures (AMBU 20 ± 6; LMAU 15 ± 7 cm H₂O; P = 0.001). There was no statistical difference between the two devices for overall success rate, insertion time, number of adjustments, laryngeal alignment, blood-staining, and sore throat (P ≥ 0.05). The AMBU AuraOnce disposable laryngeal mask provided a higher oropharyngeal leak pressure compared to the LMA Unique in spontaneously breathing adult patients.