The second-generation air-Q intubating laryngeal mask for airway maintenance during anaesthesia in adults: a report of the first 70 uses

Optical Devices in Tracheal Intubation-State of the Art in 2020

The review article is focused on developments in optical devices, other than laryngoscopes, in airway management and tracheal intubation. It brings information on advantages and limitations in their use, compares different devices, and summarizes benefits in various clinical settings. Supraglottic airway devices may be used as a conduit for fiberscope-guided tracheal intubation mainly as a rescue plan in the scenario of difficult or failed laryngoscopy. Some of these devices offer the possibility of direct endotracheal tube placement. Hybrid devices combine the features of two different intubating tools. Rigid and semi-rigid optical stylets represent another option in airway management. They offer benefits in restricted mouth opening and may be used also for retromolar intubation. Awake flexible fiberoptic intubation has been a gold standard in predicted difficult laryngoscopy for decades. Modern flexible bronchoscopes used in anesthesia and intensive care are disposable devices and contain optical lenses instead of fibers. Endotracheal tubes with an incorporated optics are used mainly in thoracic anesthesia for lung separation. They are available in double-lumen and single-lumen versions. They offer a benefit of direct view to the carina and do not require flexible fiberscope for their correct placement.

Low skill fibreoptic intubation using i-gel™ and air-Q™ in simulated difficult airways: A randomised study in manikin and in patients

Background:

Fibreoptic intubation via a supraglottic device (SAD) is ‘low skill fibreoptic intubation’ (LSFOI). ‘Standard’ second generation SADs (i-gelTM) have a gastric port. ‘Specialised’ second generation SADs (air-QTM) are designed to facilitate LSFOI and have wider ventilation ports. Our hypothesis was that performance of LSFOI differs between i-gelTM and air-QTM in a manikin with a simulated difficult airway.

Methods:

Our primary outcome was fibreoptic intubation success rate. Our secondary outcomes included SAD insertion and LSFOI times. A difficult airway was simulated by applying a hard cervical collar to a manikin. Anaesthetists performed LSFOI serially using both SADs in a random sequence. In the manikin study, 80 anaesthetists were recruited. To test the robustness of the conclusion from our manikin study, we repeated the study in 22 anaesthetised patients. Patients were fitted with the same cervical collar and randomly allocated to either devices. We used McNemar’s statistical test to analyse our primary outcome of successful intubations and paired nominal data. A Wilcoxon signed-ranks test was used to analyse nonparametric paired data and a Mann–Whitney U test was used for unpaired data analysis where appropriate. A p-value of <0.05 was considered statistically significant.

Results:

In the manikin study, the i-gelTM was superior to the air-QTM for successful tracheal intubation (98.8% vs 83.8%, respectively; p=0.002) and LSFOI times (34.0 s vs 36.0 s, respectively; p=0.012). In the patient study, LSFOI success rates were not significantly different between i-gelTM and air-QTM (100% vs 91.6%, respectively; p=0.545) but intubation times were shorter (52.5 s vs 60.0 s, respectively; p=0.036).

Conclusion:

In conclusion, we obtained LSFOI success rates for the i-gelTM or air-QTM of 98.8% and 83.8% respectively in a manikin; and 100% and 91.6% respectively in patients. It is in fact ‘low skill’ as many participants were successful despite no prior experience with LSFOI. The i-gelTM is superior for LSFOI compared with the air-QTM. This is despite being a ‘standard’ second generation SAD as compared to a ‘specialised’ second generation SAD (air-QTM).

Trial Registration:

The manikin and patient studies were conducted after being approved by the SingHealth Centralised Institutional Review Board (CRB reference number 2014/2039 and 2016/2069, respectively). The patient study was registered at ClinicalTrials.gov (ID: NCT02663843).

Rescue supraglottic airway devices at caesarean delivery: What are the options to consider?

Tracheal intubation is considered the gold standard means of securing the airway in obstetric general anaesthesia because of the increased risk of aspiration. Obstetric failed intubation is relatively rare. Difficult airway guidelines recommend the use of a supraglottic airway device to maintain the airway and to allow rescue ventilation. Failed intubation is associated with a further increased risk of aspiration, therefore there is an argument for performing supraglottic airway-guided flexible bronchoscopic intubation (SAGFBI). The technique of SAGFBI has a high success rate in the non-obstetric population, it protects the airway and it minimises task fixation on repeated attempts at laryngoscopic tracheal intubation. However, after failed intubation via laryngoscopy, there is a lack of specific recommendations or indications for SAGFBI in current obstetric difficult airway guidelines in relation to achieving tracheal intubation. Our narrative review explores the issues pertaining to airway management in these cases: the use of supraglottic airway devices and the techniques of, and technical issues related to, SAGFBI. We also discuss the factors involved in the decision-making process as to whether to proceed with surgery with the airway maintained only with a supraglottic airway device, or to proceed only after SAGFBI.

Direct and indirect low skill fibre-optic intubation: A randomised crossover manikin study of six supraglottic airway devices

Background and Aims:

Fibre-optic intubation (FOI) through supraglottic airway devices (SADs) is useful in the management of the difficult airway. We compared two methods of FOI through seven SADs in a randomised crossover manikin study to assess each device's performance and discuss implications on SAD selection.

Methods:

Thirty anaesthetsiologists, 15 seniors and 15 juniors, each performed low skill FOI (LSFOI) with seven SADs using both 'direct' and 'indirect' methods. The order of method and device used were randomised. The primary end point was success rate of intubation; secondary end points were time taken for intubation, incidence of difficulties with direct and indirect LSFOI and operator device preference. Statistical analysis was with univariable analysis and comparison of proportions.

Results:

Data from six devices were analysed due to a protocol breach with one SAD. There was no difference in intubation success rate across all SADs and intubation methods. Intubation time was significantly shorter in AmbuAuragain than other SADs and shorter with the direct method of LSFOI than the indirect method (mean difference of 6.9 s, P = 0.027). Ambu Auragain had the least SAD and bronchoscope-related difficulties. Seniors had significantly shorter mean intubation times than juniors by 11.6 s (P = 0.0392). The most preferred SAD for both methods was AmbuAuragain.

Conclusion:

Low skill FOI consistently achieves a high intubation success rate regardless of experience, choice of method, or SAD used. SAD design features may significantly affect the performance of low skill FOI.

Air-Q® versus LMA Fastrach™ for fiberoptic-guided intubation: A randomized cross-over manikin trial

INTRODUCTION

Airway management is still a major cause of anesthesia-associated morbidity and mortality. Supraglottic devices are recommended in difficult airway management guidelines. The aim of this study was to compare the performance of the Air-Q^® and the LMA Fastrach™ for fiberoptic guided tracheal intubation.

METHODS

Thirty-three anesthesia trainees participated in this randomized crossover study. Time to insert the dedicated airways (insertion of the airway into the manikin and delivery of two breaths), time to tracheal intubation (fiberoptic-guided tracheal intubation), time to remove the dedicated airway (removal of the Air-Q^®/LMA Fastrach™ over the tracheal tube) and the opinion of the ease of use of the anesthesia trainees were measured.

RESULTS

There was 100% success rate for tracheal intubation with both devices on the first attempt. Time to insert the dedicated device and deliver two breaths was 10±3s for the Air-Q^® and 11±3s for the LMA Fastrach™, P=.07. Time taken to intubate the trachea was shorter with the air-Q^®, 38±15 s, than with the LMA Fastrach™, 47±19s, P=.017. Overall procedure time was significantly shorter with the Air-Q^® as compared with the LMA Fastrach™, with a mean time of 74±21s and 87±28s respectively, P=.002. Air-Q^® removal was considered easier than LMA Fastrach™ removal, P=.005. There were no tube dislodgements during the removal of the dedicated airways.

CONCLUSIONS

Inexperienced anesthesia residents can perform fiberoptic-guided intubation through Air-Q^® and LMA Fastrach™ in a clinically acceptable time with high success.

Comparison of oropharyngeal leak pressure of air-Q™, i-gel™, and laryngeal mask airway supreme™ in adult patients during general anesthesia: A randomized controlled trial

Study Objective:

Various randomized controlled trials and a meta-analysis have compared i-gel™ and laryngeal mask airway Supreme™ (LMA-S™) in adult patients and found that both the devices provided equivalent oropharyngeal leak pressure (OLP). However, no randomized controlled trial has compared air-Q™ with i-gel™ and LMA-S™ in adult patient. Hence, we designed this study to compare air-Q™ with LMA-S™ and i-gel™ in adult patients.

Materials and Methods:

A total of 75 adult patients of the American Society of Anesthesiologists physical status I/II of both sexes, between 18 and 60 years, were included in this prospective randomized controlled trial conducted in a tertiary care center. Randomization of patients was done in three equal groups according to the insertion of supraglottic airway device by a computer-generated random number sequence: group air-Q™ (n = 25), group i-gel™ (n = 25), and group LMA-S™ (n = 25). Primary outcome of this study was OLP. We also recorded time for successful placement of device, ease of device insertion, number of attempts to insert device, and ease of gastric tube insertion along with postoperative complications.

Results:

The mean ± standard deviation OLP of air-Q™, i-gel™, and LMA-S™ was 26.13 ± 4.957 cm, 23.75 ± 5.439 cm, and 24.80 ± 4.78 cm H₂O (P = 0.279). The first insertion success rate for air-Q™, i-gel™, and LMA-S™ was 80%, 76%, and 92%, respectively (P = 0.353). The insertion time of air-Q™, i-gel™, and LMA-S™ was 20.6 ± 4.4, 14.8 ± 5.4, and 15.2 ± 4.7 s, respectively (P = 0.000). Time taken for air-Q™ insertion was significantly higher than time taken for i-gel™ (mean difference 5.8 s, P < 0.0001) and LMA-S™ (mean difference 5.4 s, P = 0.0001) insertion. Postoperative complications were similar with all three devices.

Conclusions:

We concluded that air-Q™, i-gel™, and LMA-S™ were equally efficacious in terms of routine airway management in adult patients with normal airway anatomy.

Comparative Efficacy of the Air-Q Intubating Laryngeal Airway during General Anesthesia in Pediatric Patients: A Systematic Review and Meta-Analysis

Air-Q® (air-Q) is a supraglottic airway device which can be used as a guidance of intubation in pediatric as well as in adult patients. We evaluated the efficacy and safety of air-Q compared to other airway devices during general anesthesia in pediatric patients by conducting a systematic review and meta-analysis. A total of 10 studies including 789 patients were included in the final analysis. Compared with other supraglottic airway devices, air-Q showed no evidence for a difference in leakage pressure and insertion time. The ease of insertion was significantly lower than other supraglottic airway devices. The success rate of intubation was significantly lower than other airway devices. However, fiberoptic view was better through the air-Q than other supraglottic airway devices. Therefore, air-Q could be a safe substitute for other airway devices and may provide better fiberoptic bronchoscopic view.

The self-pressurising air-Q® Intubating Laryngeal Airway for airway maintenance during anaesthesia in adults: a report of the first 100 uses

The self-pressurising air-Q® Intubating Laryngeal Airway is a new, commercially available, supraglottic airway device that incorporates a self-regulating periglottic cuff. In this retrospective review, we describe our initial clinical experience using the device in 100 patients. The ease and number of insertion attempts, airway seal pressure, device positioning, intubation success and oropharyngeal morbidity were recorded. The air-Q Intubating Laryngeal Airway was successfully inserted in all 100 patients and functioned adequately as a primary airway in 70 of the 72 patients in which it was used for this purpose. The median (interquartile range [range]) airway seal pressure was 22 (19-29, [10-40]) cmH2O. Intubation via the air-Q Intubating Laryngeal Airway was successful in 28 of 29 (97%) patients. Eleven percent of patients complained of sore throat postoperatively before discharge. In our series, the air-Q Intubating Laryngeal Airway performed adequately as a primary airway during anaesthesia with respect to ease of insertion, adequacy of airway maintenance and as a conduit for intubation in both anticipated and unanticipated difficult airways. Although our initial experience is positive, further investigation with larger numbers of observations are needed as the upper limits of the 95% confidence intervals for device failure (the worst failure rate the clinician could expect) are still high.

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.