Comparison of LMA Unique, Ambu laryngeal mask and Soft Seal laryngeal mask during routine surgical procedures

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.

Does Baska mask deserve its own niche among extraglottic airway devices? A prospective, single-arm study

Background and Aims

A variety of extraglottic airway devices (EADs) are available. Main concerns with EADs are protection against aspiration and ability to ventilate patients with high airway pressures. Baska mask meets these criteria and is the only third-generation device available for clinical use.

Methods

After institutional ethics committee approval and informed consent were obtained, this prospective study was performed in 100 adult patients undergoing surface surgeries at a tertiary referral centre. The primary outcome was the success rate of insertion, while the secondary outcomes were the sealing pressure, stability of the device and the perioperative complications of Baska mask. We then compared it with other currently used EADs.

Results

The first attempt at insertion and overall success rates, showed values of 81% and 98%, respectively. Insertion was quick (median 12; interquartile range [IQR] 9-15 s). The mask sealing pressure, was 35 cmH2O (median [IQR 20-50 cmH2O]). Also, the mask remained stable in 95% of patients intraoperatively. Sore throat and dysphagia were seen in 37% and 24% of patients, respectively. No patient had laryngospasm or desaturation at any time. It compared favourably well with other EADs, while achieving higher sealing pressures.

Conclusion

We found that the Baska mask performs well with excellent first attempt at insertion and overall success rates, higher sealing pressures and minimal complications compared to currently used EADs in clinical anaesthesia.

Blind vs. video-laryngoscope-guided laryngeal mask insertion: A prospective randomized comparison of oropharyngeal leak pressure and fiberoptic grading

PURPOSE

Laryngeal Mask Airway (LMA) insertion may not always be smooth without complications. Controversial results of several studies evaluating ideal insertion conditions have been published. This study compared the oropharyngeal leak pressure values and fiberoptic grading scores between blind and video-laryngoscope-guided LMA insertion.

METHODS

Patients were randomly assigned into blind insertion (n = 50) and video-laryngoscope guided insertion (n = 50) groups. The oropharyngeal leak pressure, peak airway pressure, fiberoptic grading score, first attempt success rate, hemodynamic parameters, and complications were recorded.

RESULTS

All laryngeal mask airways were successfully inserted in both groups at the first attempt. The fiberoptic staging scores were: grade 1 in 8.2% of patients, grade 2 in 24.4% of patients, grade 3 in 44.8% of patients, grade 4 in 22.4% of patients in the control group. On the other hand, grade 1 in 2.2% of patients, grade 2 in 28.6% of patients, grade 3 in 51% of patients, grade 4 in 8.2% of patients in the VL group (p = 0.260). The peak airway pressure and LMA insertion time were similar between groups. However, the oropharyngeal leak pressure before extubation was significantly higher in the video-laryngoscope-guided insertion than blind insertion (36.29 ± 7.09 vs. 33.79 ± 8.84 cmH2O respectively, p = 0.04).

CONCLUSIONS

The findings of our study suggest that the video-laryngoscope-guided LMA-Classic insertion with a standard blade technique may be a helpful alternative to blind insertion.

A comparison of blind intubation with the intubating laryngeal mask FASTRACH™ and the intubating laryngeal mask Ambu Aura-i™ a prospective randomised clinical trial

Background

The intubating laryngeal mask Fastrach™ is considered a gold standard for blind intubation as well as for fibreoptic guided intubation via a laryngeal mask. Recently, a single use version of the mask has been introduced. We compared the Fastrach single use with the new, low-priced single use intubating laryngeal mask Ambu Aura-i™.

We hypothesised that the LMA Ambu Aura-i and the LMA Fastrach are comparable with respect to success rates for mask placement and blind tracheal intubation through the LMA device.

Methods

A prospective, randomised clinical trial. University Hospital Schleswig-Holstein, Campus Kiel, from April 2011 to April 2012.

Eighty patients undergoing general anaesthesia with planned tracheal intubation were randomised and enrolled in the study. Blind intubation was performed with either laryngeal mask using two different tracheal tubes (Rüsch Super Safety Silk™ and LMA ETT™). A crossover-design was performed after an unsuccessful procedure.

Primary outcome measure was the overall success rate of blind intubation. Secondary outcome measures were the time to the first adequate ventilation, a subjective handling score, and a fibreoptic control of placement, as well as the success rate of mask placement, time for mask removal after successful intubation, differences in airway leak pressure, and the incidence of postoperative sore throat and hoarseness.

Results

The success rate of tracheal intubation with the Fastrach for the first and second attempt was significantly better compared with the Ambu Aura-i. Tracheal intubation was also significantly faster (14.1 s. ±4.4 versus 21.3 s. ±9.0; p < 0.01), and the time interval for mask removal after successful intubation was significantly shorter using the Fastrach device (24.0 s. ±8.2 versus 29.4 s. ±7.5; p < 0.001). There were no significant differences between groups regarding the incidence of postoperative sore throat and hoarseness.

Conclusion

Both laryngeal mask devices are suitable for ventilation and oxygenation. Blind intubation remains the domain of the LMA Fastrach, the Ambu Aura-i is not suitable for blind intubation.

Trial registration

Clinicaltrials.gov Identification Number NCT03109678, retrospectively registered on April 12, 2017.

Conditions for laryngeal mask airway placement in terms of oropharyngeal leak pressure: a comparison between blind insertion and laryngoscope-guided insertion

Background

Insertion under laryngoscopic guidance has been used to achieve ideal positioning of the laryngeal mask airway (LMA). However, to date, the efficacy of this technique has been evaluated only using fiberoptic evaluation, and the results have been conflicting. Other reliable tests to evaluate the efficacy of this technique have not been established. Recently, it has been suggested that the accuracy of LMA placement can be determined by clinical signs such as oropharyngeal leak pressure (OPLP). The aim of this study was to assess the efficacy of LMA insertion under laryngoscopic guidance using OPLP as an indicator.

Methods

After approved by the institutional ethics committee, a prospective comparison of 100 patients divided into 2 groups (50 with blind technique and 50 with the laryngoscope technique) were evaluated. An LMA (LarySeal™, Flexicare medical Ltd., UK) was inserted using the blind approach in the blind insertion group and using laryngoscopy in the laryngoscope-guided insertion group. The OPLP, fiberoptic position score, whether the first attempt at LMA insertion was successful, time taken for insertion, ease of LMA insertion, and adverse airway events were recorded.

Results

Data were presented as mean ± standard deviation. The OPLP was higher in the laryngoscope-guided insertion group than in the blind insertion group (21.4 ± 8.6 cmH₂O vs. 18.1 ± 6.1 cmH₂O, p = 0.031). The fiberoptic position score, rate of success in the first attempt, ease of insertion, and pharyngolaryngeal adverse events were similar between both groups. The time taken for insertion of the LMA was significantly longer in the laryngoscope-guided insertion group, compared to blind insertion group (35.9 ± 9.5 s vs. 28.7 ± 9.5 s, p < 0.0001).

Conclusion

Laryngoscope-guided insertion of LMA improves the airway seal pressure compared to blind insertion. Our result suggests that it may be a useful technique for LMA insertion.

Trial registration

cris.nih.go.kr, identifier: KCT0001945 (2016-06-17).

Pediatric supraglottic airway devices in clinical practice: A prospective observational study

BACKGROUND

Supraglottic airway devices (SGA) are commonly used in pediatric anesthesia and serve as primary or back-up devices for difficult airway management. Most SGA are marketed without proper clinical evaluation. The purpose of this study was to evaluate the performance of the pediatric LMA Supreme™, Air-Q® and Ambu® Aura-i™.

METHODS

This prospective observational study was performed at Bern University Hospital, Switzerland. With ethics committee approval and a waiver for written informed consent 240 children undergoing elective surgery with an ASA class I-III and a weight of 5-30 kg were included. Three different pediatric supraglottic airway devices were assessed: The LMA Supreme™, Air-Q® and Ambu® Aura-i™. Primary outcome parameter was airway leak pressure. Secondary outcome parameters included first attempt and overall success rate, insertion time, fiberoptic view through the SGA, and adverse events. The primary hypothesis was that the mean airway leak pressure of each tested SGA was 20 cmH₂O ± 10%.

RESULTS

None of the SGA showed a mean airway leak pressure of 20 cmH₂O ± 10%, but mean airway leak pressures differed significantly between devices [LMA Supreme™ 18.0 (3.4) cmH₂O, Air-Q® 15.9 (3.2) cmH₂O, Ambu® Aura-i™ 17.3 (3.7) cmH₂O, p < 0.001]. First attempt success rates (LMA Supreme™ 100%, Air-Q® 90%, Ambu® Aura-i™ 91%, p = 0.02) and overall success rates (LMA Supreme™ 100%, Air-Q® 91%, Ambu® Aura-i™ 95%, p = 0.02) also differed significantly. Insertion times ranged from 20 (7) seconds (Air-Q®) to 24 (6) seconds (LMA Supreme™, <p = 0.005). Insertion was rated easiest with the LMA Supreme™ (very easy in 97% vs. Air-Q® 70%, Ambu® Aura-i™ 72%, p < 0.001). Fiberoptic view was similar between the SGA. Adverse events were rare.

CONCLUSIONS

Airway leak pressures ranged from 16 to 18 cmH₂O, enabling positive pressure ventilation with all successful SGA. The highest success rates were achieved by the LMA Supreme™, which was also rated easiest to insert.

TRIALS REGISTRATION

ClinicalTrials.gov , identifier NCT01625858 . Registered 31 May 2012.

ProSeal versus Classic laryngeal mask airway (LMA) for positive pressure ventilation in adults undergoing elective surgery

BACKGROUND

The development of supraglottic airway devices has revolutionized airway management during general anaesthesia. Two devices are widely used in clinical practice to facilitate positive pressure ventilation: the ProSeal laryngeal mask airway (pLMA) and the Classic laryngeal mask airway (cLMA). It is not clear whether these devices have important clinical differences in terms of efficacy or complications.

OBJECTIVES

To compare the effectiveness of the ProSeal laryngeal mask airway (pLMA) and the Classic LMA (cLMA) for positive pressure ventilation in adults undergoing elective surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2017, Issue 3) in the Cochrane Library; MEDLINE (Ovid SP, 1997 to April 2017); Embase (Ovid SP, 1997 to April 2017); the Institute for Scientific Information (ISI) Web of Science (1946 to April 2017); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO host, 1982 to April 2017).We searched trial registries for ongoing studies to April 2017.We did not impose language restrictions. We restricted our search to the time from 1997 to April 2017 because pLMA was introduced into clinical practice in the year 2000.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that compared the effectiveness of pLMA and cLMA for positive pressure ventilation in adults undergoing elective surgery. We planned to include only data related to the first phase of cross-over RCTs.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by the Cochrane Collaboration.

MAIN RESULTS

We included eight RCTs that involved a total of 829 participants (416 and 413 participants in the pLMA and cLMA groups, respectively). We identified six cross-over studies that are awaiting classification; one is completed but has not been published, and data related to the first treatment period for the other five studies were not yet available. Seven included studies provided data related to the primary outcome, and eight studies provided data related to more than one secondary outcome.Our analysis was hampered by the fact that a large proportion of the included studies reported no events in either study arm. No studies reported significant differences between devices in relation to the primary review outcome: failure to adequately mechanically ventilate. We evaluated this outcome by assessing two variables: inadequate oxygenation (risk ratio (RR) 0.75, 95% confidence interval (CI) 0.17 to 3.31; four studies, N = 617) and inadequate ventilation (not estimable; one study, N = 80).More time was required to establish an effective airway using pLMA (mean difference (MD) 10.12 seconds, 95% CI 5.04 to 15.21; P < 0.0001; I² = 73%; two studies, N = 434). Peak airway pressure during positive pressure ventilation was lower in cLMA participants (MD 0.84, 95% CI 0.02 to 1.67; P = 0.04; I² = 0%; four studies, N = 259). Mean oropharyngeal leak (OPL) pressure was higher in pLMA participants (MD 6.93, 95% CI 4.23 to 9.62; P < 0.00001; I² = 87%; six studies, N = 709).The quality of evidence for all outcomes, as assessed by GRADE score, is low mainly owing to issues related to blinding and imprecision.Data show no important differences between devices with regard to failure to insert the device, use of an alternate device, mucosal injury, sore throat, bronchospasm, gastric insufflation, regurgitation, coughing, and excessive leak. Data were insufficient to allow estimation of differences for obstruction related to the device. None of the studies reported postoperative nausea and vomiting as an outcome.

AUTHORS' CONCLUSIONS

We are uncertain about the effects of either of the airway devices in terms of failure of oxygenation or ventilation because there were very few events. Results were uncertain in terms of differences for several complications. Low-quality evidence suggests that the ProSeal laryngeal mask airway makes a better seal and therefore may be more suitable than the Classic laryngeal mask airway for positive pressure ventilation. The Classic laryngeal mask airway may be quicker to insert, but this is unlikely to be clinically meaningful.

Extraglottic airway devices: A review

Extraglottic airway devices (EAD) have become an integral part of anesthetic care since their introduction into clinical practice 25 years ago and have been used safely hundreds of millions of times, worldwide. They are an important first option for difficult ventilation during both in-hospital and out-of-hospital difficult airway management and can be utilized as a conduit for tracheal intubation either blindly or assisted by another technology (fiberoptic endoscopy, lightwand). Thus, the EAD may be the most versatile single airway technique in the airway management toolbox. However, despite their utility, knowledge regarding specific devices and the supporting data for their use is of paramount importance to patient's safety. In this review, number of commercially available EADs are discussed and the reported benefits and potential pitfalls are highlighted.

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.

The air-Q(®) intubating laryngeal airway vs the LMA-ProSeal(TM) : a prospective, randomised trial of airway seal pressure

We performed a prospective, open-label, randomised controlled trial comparing the air-Q(®) against the LMA-ProSeal™ in adults undergoing general anaesthesia. One hundred subjects (American Society of Anesthesiologists physical status 1-3) presenting for elective, outpatient surgery were randomly assigned to 52 air-Q(®) and 48 ProSeal devices. The primary study endpoint was airway seal pressure. Oropharyngolaryngeal morbidity was assessed secondarily. Mean (SD) airway seal pressures for the air-Q(®) and ProSeal were 30 (7) cmH (2) O and 30 (6) cmH(2) O, respectively (p = 0.47). Postoperative sore throat was more common with the air-Q(®) (46% vs 38%, p = 0.03) as was pain on swallowing (30% vs 5%, p = 0.01). In conclusion, the air-Q(®) performs well as a primary airway during the maintenance of general anaesthesia with an airway seal pressure similar to that of the ProSeal, but with a higher incidence of postoperative oropharyngolaryngeal complaints.

Randomised comparison of the LMA Supreme with the I-Gel in spontaneously breathing anaesthetised adult patients

We compared the performance of the LMA Supreme (SLMA) with the I-Gel during anaesthesia in spontaneously breathing adult patients. Ninety patients with American Society of Anesthesiologists physical status I or II were studied in a prospective randomised controlled study. Our primary outcome measure was oropharyngeal leak pressure. We also compared the overall insertion success rate, ease of insertion, adequacy of ventilation and incidence of complications. The mean (SD), oropharyngeal leak pressure for the SLMA was 25.6 (5.1) cmH2O, which was greater than for the I-Gel 20.7 (5.9) cmH2O (P = 0.0001). The first attempt and overall insertion success rates were similar between the two groups (SLMA 97.8 and 97.8%; I-Gel 93.3 and 100%, P = 0.132). The SLMA was rated easier to insert than the I-Gel (P = 0.011), but the time taken for insertion (P = 0.433) was similar. The incidence of complications was low in both groups. The grade of fibreoptic view was better with the I-Gel than the SLMA (P = 0.001). We conclude that in adults with normal airways, the SLMA is easier to insert and provides a higher oropharyngeal leak pressure, but fibreoptic views are better with the i-gel.

Randomized crossover comparison between the i-gel and the LMA-Unique in anaesthetized, paralysed adults

BACKGROUND

The i-gel differs from other supraglottic airway devices, in that it has a softer, non-inflatable cuff. This study was designed to compare the performance of the i-gel and the LMA-Unique (LMA-U) when used during anaesthesia in paralysed patients.

METHODS

Both devices were studied in 39 anaesthetized, paralysed patients in a randomized crossover trial. The primary outcome was airway leak pressure. Secondary outcomes included time to insertion, the number of insertion and reposition attempts, leak volumes, and leak fractions.

RESULTS

There was no significant difference between the airway leak pressures of the two devices [median (IQR) leak pressures 25 (22-30) vs 22 (20-28) cm H(2)O for the i-gel and LMA-U, respectively; P=0.083, 95% CI of the mean difference -0.32 to 4.88 cm H(2)O]. The median (IQR) insertion time for the i-gel was significantly less than for the LMA-U [12.2 (9.7-14.3) vs 15.2 (13.2-17.3) s; P=0.007]. All the LMA-U devices and 38 of 39 i-gel airways were inserted at the first attempt. The number of manipulations required after insertion to achieve a clear airway was the same in both the groups (four in each). There were no statistically significant differences in leak volumes or leak fractions during controlled ventilation.

CONCLUSIONS

We found no difference in leak pressures and success rate of first-time insertion between the i-gel and the LMA-U. Time to successful insertion was significantly shorter for the i-gel. We conclude that the i-gel provides a reasonable alternative to the LMA-U for controlled ventilation during anaesthesia.

A comparison of the i-gel with the LMA-Unique in non-paralysed anaesthetised adult patients

SUMMARY

This study assessed two disposable devices; the newly developed supraglottic airway device i-gel and the LMA-Unique in routine clinical practice. Eighty patients (ASA 1-3) undergoing minor routine gynaecologic surgery were randomly allocated to have an i-gel (n = 40) or LMA-Unique (n = 40) inserted. Oxygen saturation, end-tidal carbon dioxide, tidal volume and peak airway pressure were recorded, as well as time of insertion, airway leak pressure, postoperative sore-throat, dysphonia and dysphagia for each device. Time of insertion was comparable with the i-gel and LMA-Unique. There was no failure in the i-gel group and one failure in the LMA-Unique group. Ventilation and oxygenation were similar between devices. Mean airway pressure was comparable with both devices, whereas airway leak pressure was significantly higher (p < 0.0001) in the i-gel group (mean 29 cmH(2)O, range 24-40) compared with the LMA-Unique group (mean 18 cmH(2)O, range 6-30). Fibreoptic score of the position of the devices was significantly better in the i-gel group. Post-operative sore-throat and dysphagia were comparable with both devices. Both devices appeared to be simple alternatives to secure the airway. Significantly higher airway leak pressure suggests that the i-gel may be advantageous in this respect.

The Soft Seal disposable laryngeal mask airway in adults: comparison of two insertion techniques without intra-oral manipulation

We investigated whether insertion of the disposable Soft Seal laryngeal mask airway (SSLM) was successful without intra-oral digital manipulation. One hundred patients undergoing anaesthesia using the SSLM were randomly assigned into two groups. Insertion was performed by either a direct or a rotational technique, both without intra-oral digital manipulation. The primary outcome measure was successful insertion at first attempt. Other outcomes included insertion time, fibreoptic assessment of the airway view and airway morbidity. The first attempt success rate was higher (98%) with the direct technique than with the rotational technique (75%; p = 0.002) but insertion time was faster with the latter method (mean [range] 15 [8-50] s) than with the direct method (20 [8-56] s; p = 0.035). Fibreoptic assessment and airway morbidity were similar in both groups. We conclude that the SSLM can be successfully inserted without intra-oral digital manipulation.

A comparison of the laryngeal tube-S and Proseal laryngeal mask during outpatient surgical procedures

BACKGROUND AND OBJECTIVE

The Laryngeal Tube Sonda (LTS) and the ProSeal Laryngeal Mask Airway (PLMA) are two new devices introduced for maintaining the airway during controlled ventilation under general anaesthesia. The present investigation compared their performance in a randomized controlled study.

METHODS

One hundred ASA I-II patients, aged 18-60 yr undergoing elective minor surgery, were randomized to receive either an LTS (n = 50) or PLMA (n = 50) for airway management. After induction of general anaesthesia, the devices were inserted, its correct placement was verified and airway leak pressure was measured. Ease of insertion, quality of airway seal, fibre-optic view and postoperative pharyngeal morbidity were examined.

RESULTS

There were no differences in patient characteristics for both groups. First-time and second-time success rates were comparable for both groups (86 vs. 88% and 96 vs. 98% in LTS and PLMA groups, respectively). The airway of one patient in each group could not be managed with these devices after three attempts. Time until delivery of first tidal volume for LTS and PLMA was 24.5 +/- 6.9 and 28.8 +/- 10.3 s. Fixation and manipulation time was 54.9 +/- 15.2 and 73.2 +/- 25 s, respectively (P < 0.05). Airway seal pressure (cm H(2)O) for LTS and PLMA was 20 +/- 8.6 and 24.1 +/- 10.8, respectively (P = 0.04). Patients were questioned on a variety of postoperative pharyngeal morbidities. Only hoarseness was more frequent in the LTS group.

CONCLUSIONS

Both devices provide a secure airway, are similar in clinical utility and are easy to insert. Better airway seal was detected in the PLMA group.