Randomized clinical trial of the i-gel™ and Magill tracheal tube or single-use ILMA™ and ILMA™ tracheal tube for blind intubation in anaesthetized patients with a predicted difficult airway

Tracheal intubation using intubating laryngeal tube iLTS-D™ and LMA Fastrach™ in 99 adult patients: A prospective multicentric randomised non-inferiority study

STUDY OBJECTIVE

This study aimed to investigate the overall success of tracheal intubation using the intubating Laryngeal Tube Suction-Disposable (iLTS-D™, VBM, Sulz a. N., Germany) compared to the Laryngeal Mask Airway (LMA) Fastrach™ (Teleflex, Athlone, Ireland). We hypothesised that the iLTS-D™ would be non-inferior to the LMA Fastrach™ for tracheal intubation and ventilation.

DESIGN

Multicentric, non-inferiority, randomised controlled study.

SETTING

Operating rooms from two tertiary and one secondary centre in Switzerland from January 2017 to July 2019. The investigators were trained anaesthetists with extensive experience with laryngeal masks but limited to laryngeal tubes. The study was discontinued after the planned interim analysis.

PATIENTS

Ninety-nine adult patients were included after randomisation. The inclusion criteria were American Society of Anesthesiologists physical status 1 to 3 in patients scheduled for elective surgery requiring tracheal intubation. Patients with a history of difficult intubation were excluded.

INTERVENTION(S)

After anaesthesia induction and once neuromuscular blockade was obtained, ventilation was initiated, and tracheal intubation was performed through the randomised device with the flexible endoscope tip placed proximally to the tip of the tracheal tube (visualised blind intubation).

MEASUREMENTS

The primary outcome was the intubation success rate after two attempts. The secondary outcomes were time to intubation, successful ventilation rate, time to achieve ventilation, and gastric access success rate.

MAIN RESULTS

The overall intubation success rate was significantly higher in the Fastrach™ group than in the iLTS-D™ group (91.8% vs 70.0%, p = 0.006). No difference was found in the ventilation success rate (94% for iLTS-D™ and 100% for LMA Fastrach™ [p = 0.829]). The time to achieve ventilation and intubation were similar between the groups. No major airway complications were noted.

CONCLUSIONS

Although both supraglottic devices provided the same effective ventilation rate, the LMA Fastrach™ was superior to the iLTS-D™ as a conduit for intubation in 99 adult patients without a known difficult intubation. These preliminary results need to be confirmed in studies that include a larger population.

TRIAL REGISTRATION

Clinicaltrials.gov, 21.09.2016, Identification Number NCT02922595.

Prehospital Supraglottic Airways: An NAEMSP Position Statement and Resource Document

Supraglottic airway (SGA) devices provide effective conduits for oxygenation and ventilation and may offer protection from gastric aspiration. SGA devices are widely used by EMS clinicians as both rescue and primary airway management devices. While in common use for more than four decades, major developments in SGA education, science, and technology have influenced clinical strategies of SGA insertion and use in prehospital airway management for patients of all ages. NAEMSP recommends:SGAs have utility as a primary or secondary EMS airway intervention. EMS agencies should select SGA strategies that best suit available resources and local clinician skillset, as well as the nature of their clinical practice setting.EMS agencies that perform endotracheal intubation must also equip their clinicians with SGA devices and ensure adequate training and competence.In select situations, drug-assisted airway management may be used by properly credentialed EMS clinicians to facilitate SGA insertion.Confirmation of initial and continuous SGA placement using waveform capnography is strongly encouraged as a best practice.When it is functioning properly, EMS clinicians should refrain from converting an SGA to an endotracheal tube. The decision to convert an SGA to an endotracheal tube must consider the patient's condition, the effectiveness of SGA ventilations, and the clinical context and course of initial SGA insertionSGA training, competency, and clinical use must be continuously evaluated by EMS agencies using focused quality management programs.

2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway

The American Society of Anesthesiologists; All India Difficult Airway Association; European Airway Management Society; European Society of Anaesthesiology and Intensive Care; Italian Society of Anesthesiology, Analgesia, Resuscitation and Intensive Care; Learning, Teaching and Investigation Difficult Airway Group; Society for Airway Management; Society for Ambulatory Anesthesia; Society for Head and Neck Anesthesia; Society for Pediatric Anesthesia; Society of Critical Care Anesthesiologists; and the Trauma Anesthesiology Society present an updated report of the Practice Guidelines for Management of the Difficult Airway.

Intubating Through Supraglottic Airway Devices: A Narrative Review

Implication Statement: Despite the increasing popularity of video laryngoscopes, the supraglottic airway device (SAD) remains a critical airway rescue tool. The SAD provides a conduit for tracheal intubation in failed laryngoscopy. This article aims to help the operator: (1) select an intubating SAD with consistent performance; (2) inform the appropriate SAD-endotracheal tube pairings; and (3) explain various SAD and endotracheal tube maneuvers available to increase chances of successful intubation. Objectives: The first supraglottic airway device (SAD) was introduced more than thirty years ago. Since then, SADs have undergone multiple iterations and improvements. The SAD remains an airway rescue device for ventilation and an intubation conduit on difficult airway algorithms. Data Sources: Several SADs are specifically designed to facilitate tracheal intubation, i.e., “intubating SADs,” while most are “non-intubating SADs.” The two most commonly reported tracheal intubation methods via the SADs are the blind and visualized passage of the endotracheal tube (ETT) preloaded on a fiberoptic scope. Fiberoptic guided tracheal intubation (FOI) via an intubating SAD generally has higher success rates than blind intubations and is thus preferred. However, fiberscopes might not always be readily available, and anesthesiologists should be skilled to successfully intubate blindly through a SAD. Summery: This narrative review describes intubating SAD with consistent performance, appropriate SAD-ETT pairings, and various SAD and ETT maneuvers to increase successful intubation chances.

Dimensional compatibility and limitations of tracheal intubation through supraglottic airway devices: a mannequin-based in vitro study

BACKGROUND

Flexible bronchoscope-guided tracheal intubation through supraglottic airway devices (SGAs) is a well-established element of difficult intubation algorithms. Success can be limited by dimensional incompatibilities between tracheal tubes (TTs) and SGAs.

METHODS

In this in vitro study, we tested the feasibility of TT passage through SGAs, removal of SGAs over TTs, and the ability to guide the flexible bronchoscope with 13 TT brands (internal diameter, 6.5-8.0 mm) and ten different SGAs (#4 and #5) in an intubation mannequin.

RESULTS

We tested 1,040 combinations of SGAs and TTs. Tracheal tube passage failed in 155 (30%) combinations of the five tested first-generation SGAs (117 [46%] with SGA #4, 38 [15%] with SGA #5) and in three (0.6%) combinations of the five tested second-generation SGAs (two [0.8%] with SGA #4 and one [0.4%] with SGA #5). The reason for failed passage of a TT through a first-generation SGA consistently was a too-narrow SGA connector. Removal of the SGA over the TT in the 882 remaining combinations was impossible for all sizes of reinforced TTs, except the Parker Reinforced TT, and was possible for all non-reinforced TTs. Only one combination with SGA #4 and 84 combinations with SGA #5 were not ideal to adequately guide the flexible bronchoscope.

CONCLUSION

Clinically relevant combinations of adult-size TTs and SGAs can be incompatible, rendering flexible bronchoscope-guided tracheal intubation through an SGA impossible. Additional limitations exist regarding removal of the SGA and maneuverability of the flexible bronchoscope.

The distance between the glottis and the cuff of a tracheal tube placed through three supraglottic airway devices in children: A randomised controlled trial

BACKGROUND

After tracheal tube insertion via various types of supraglottic airway devices, the distance from the tube cuff to the vocal cords has not been evaluated in children.

OBJECTIVES

The aim of this study was to evaluate the position of a tracheal tube cuff relative to the glottis in children when one of three supraglottic airway devices (I-gel, AuraGain and air-Q laryngeal airway) are used as intubation conduits.

DESIGN

A randomised controlled trial.

SETTING

Tertiary children's hospital.

PATIENTS

Children aged less than 7 years.

INTERVENTION

In vivo fibre-optic assessment and in vitro measurement.

MAIN OUTCOME MEASURES

The main outcome was the safety margin: the distance between the ventilation outlet of the supraglottic airway device and the beginning of the proximal cuff minus that from the ventilation outlet to the glottis. The maximum inner diameter of the cuffed tracheal tube that could be inserted, the fibre-optic view score and the oropharyngeal leak pressure were also evaluated.

RESULTS

The three devices exhibited significant differences in the distance from the ventilation outlet to the glottis (mean ± SD): I-gel 3.6 ± 0.6 cm, AuraGain 3.8 ± 0.7 cm, air-Q 2.8 ± 1.0 cm (P < 0.001). The safety margin was greatest with the air-Q and narrowest with the I-gel: I gel 1.9 ± 1.1 cm, AuraGain 4.4 ± 0.7 cm and air-Q 7.9 ± 1.1 cm. Using the AuraGain and air-Q, the cuffs of the tracheal tubes were predicted to be located below the glottis with one-size and two-size smaller tracheal tubes in all patients. However, using I-gel, the cuffs would be below the glottis in 69% (95% CI 49.6 to 84.5) and 29% (95% CI 14.0 to 48.4) of the patients with a one-size and two-size smaller tube, respectively.

CONCLUSION

The AuraGain and air-Q are well tolerated intubating conduits. The possibility of vocal cord damage is higher when the I-gel is used.

TRIAL REGISTRATION

www.clinicaltrials.gov (number: NCT03156166).

Fiberoptic-Guided and Blind Tracheal Intubation Through iLTS-D, Ambu® Auragain™, and I-Gel® Supraglottic Airway Devices: A Randomized Crossover Manikin Trial

BACKGROUND

The use of supraglottic airway devices (SADs) is becoming more widespread. However, there is little evidence to show which device is best in an emergent clinical scenario.

OBJECTIVE

We compared both fiberoptic-guided and blind tracheal intubation through the Intubating Laryngeal Tube Suction-Disposal (iLTS-D), the AuraGain™, and the i-gel® in an airway manikin.

METHODS

Thirty residents were included in a randomized trial to perform both fiberoptic-guided and blind tracheal intubation using the iLTS-D, the AuraGain, and the i-gel. The main endpoint was the total time taken to achieve successful fiberoptic intubation through the SAD. Additional endpoints included total time for blind intubation, SAD insertion time, tracheal tube insertion time, intubation success rate, fiberoptic view, and maneuvers performed to achieve tracheal intubation.

RESULTS

All participants performed fiberoptic intubation using all three SADs on the first attempt. The total time to fiberoptic tracheal intubation using the i-gel, AuraGain, and iLTS-D was 42 s, 56 s, and 56 s, respectively. The blind tracheal intubation success rate was 80% with the iLTS-D, 43% with the i-gel, and 0% with the AuraGain. The total time for blind tracheal intubation through the i-gel and the iLTS-D was 29 s and 40 s, respectively. Laryngeal view grades were significantly poorer with the iLTS-D compared to the other devices. The iLTS-D required significantly more maneuvers to achieve successful tracheal intubation.

CONCLUSIONS

In an airway manikin, the iLTS-D, AuraGain, and i-gel appear to be reliable devices for airway rescue and fiberoptic-guided tracheal intubation. The iLTS-D is recommended for blind tracheal intubation.

Comparative study of fiber-optic guided tracheal intubation through intubating laryngeal mask airway LMA Fastrach™ and i-gel in adult paralyzed patients

Background:

The i-gel is a novel and innovative supraglottic airway management device used both as an airway rescue device and as a conduit for fiberoptic intubation. In this prospective randomized study, we compared fiberoptic-guided tracheal intubation through the i-gel and LMA Fastrach™ in adult paralyzed patients.

Materials and Methods:

After ethical committee approval and written informed consent, 60 patients of either sex were randomly allocated to either group of supraglottic airway device (SGAD). After successful insertion of the SGAD, the fiberoptic bronchoscope (FOB)-guided tracheal intubation was done through the respective SGAD. The primary objectives were the ease and time taken for fiberoptic-guided intubation in either group. Secondary variables included time taken for successful placement of SGAD, ease of insertion of SGAD, airway seal pressure, ease and time of removal of SGAD, variation in hemodynamic parameters, and complications if any.

Results:

Time taken for tracheal intubation in LMA Fastrach™ group was 69.53 ± 5.09 s and for the i-gel group it was 72.33 ± 6.73 s. It was seen that it was easy to insert the endotracheal tube (ETT) in 93.3% patients in the LMA Fastrach™ group and 96.7% patients in the i-gel group. Airway seal pressure was higher for the LMA Fastrach™ group. Both the SGADs were comparable in the number of attempts of insertion, ease of insertion, and insertion time. In addition, the hemodynamic variables noted did not show any increase after insertion of SGAD. There was no difficulty encountered in removal of either SGAD.

Conclusion:

I-gel may be a reliable and cost-effective alternative to LMA Fastrach™ for fibreoptic-guided tracheal intubation.

I-Gel as an intubation conduit: Comparison of three different types of endotracheal tubes

BACKGROUND AND AIMS

I-Gel®, a novel SAD has been introduced as a ventilating device but has widely gained popularity as conduit for intubation. Unlike intubating laryngeal mask airway (ILMA), I-Gel® does not have an endotracheal tube specially designed for it. Hence the aim of this study was to compare the rate of successful intubation via I-Gel® using three different types of endotracheal tubes.

METHODS

We randomised 75 American Society of Anesthesiologists (ASA) physical status I and II patients, between the age group 18-60 years of either sex undergoing elective surgery under general anaesthesia into three groups on the basis of endotracheal tube (ETT), used for intubation via I-Gel®: Group P (Polyvinyl chloride ETT), Group I (Intubating laryngeal mask airway ETT), Group F (flexometallic ETT). After following the standard induction protocol, appropriate size I Gel® was inserted in all patients. Thereafter group specific ETT was inserted via I-Gel®. We recorded and compared the time taken for successful intubation, the success rate, number of attempts taken, manoeuvres used, and complications among three different types of ETT. Quantitative variables were compared using Kruskal Wallis test and the qualitative variables were compared using Chi-square test.

RESULTS

The time taken for successful intubation was least in group P (10.51 ± 3.82 seconds). Group P also had the highest first attempt (68%) and overall rate of successful intubation (88%).

CONCLUSION

PVC ETT had highest first attempt success rate and required minimum time for endotracheal intubation via I-Gel® when compared to ILMA ETT and Flexible ETT.

Supraglottic airway devices as a strategy for unassisted tracheal intubation: A network meta-analysis

We aimed to compare the effectiveness of supraglottic airway devices as a strategy for unassisted tracheal intubation. Accordingly, we searched the OVID-MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, KoreaMed, and Google Scholar databases to identify all relevant randomized controlled trials (RCTs) on supraglottic airway devices as a strategy for tracheal intubation published until May 2017. The primary outcome was the overall success rate of intubation by the intention to treat (ITT) strategy. The secondary outcomes of the study were the overall success rate of tracheal intubation by the per protocol (PP) strategy and the success rate of tracheal intubation at first attempt by ITT and PP. We conducted a network meta-analysis with a mixed-treatment comparison method to combine direct and indirect comparisons among supraglottic airway devices. Of 1396 identified references, 16 RCTs (2014 patients) evaluated unassisted intubation with supraglottic airway devices. Patients were grouped according to the type of device used: LMA-CTrach, LMA-Fastrach, Air-Q, i-gel, CobraPLA, Ambu-Aura, or single-use LMA devices. Based on the surface under the cumulative ranking curve, the three best supraglottic airway devices for use as a strategy for unassisted tracheal intubation were LMA-CTrach (which included video-assisted tracheal tube guidance), single-use LMA-Fastrach, and LMA-Fastrach. LMA-Fastrach showed a higher success rate of intubation than did i-gel, CobraPLA, Air-Q, and Ambu-Aura. However, this study was limited by the small number of eligible RCTs. Therefore, well-designed RCTs performed on large patient populations are required to increase the confidence of the results.

Assessment of awake i-gel™ insertion for fiberoptic-guided intubation in patients with predicted difficult airway: A prospective, observational study

Background and Aims:

Orotracheal intubation (OTI) with fiberoptic bronchoscope (FOB) in spontaneous ventilation is one of the main techniques for patients with predicted difficult airway. Latest generation supraglottic airway devices have been designed to allow OTI through them. We assessed the safety and effectiveness of FOB-guided OTI through i-gel™ device which was inserted in spontaneously breathing patients with predicted difficult airway.

Material and Methods:

Eighty-five patients with difficult airway predictors were included. The i-gel was inserted under oropharyngeal local anaesthesia and sedation. After checking the adequate ventilation through the i-gel with capnography curve, general anaesthesia was induced in order to introduce the endotracheal tube guided by FOB. We recorded the i-gel insertion time (t_gel), intubation time (t_int), O₂ saturation in pulse oximetry (SpO₂) at different times: basal (t₀), after 3 min of preoxygenation with a face mask at 100% FiO₂ (t₁), after i-gel mask insertion (t₂) and after intubation (t₃). Adverse events during the procedure were also recorded.

Results:

All patients were successfully intubated. SpO₂ values were: 96.9 ± 1.2 (t₀), 99.0 ± 0.9 (t₁), 96.2 ± 2.4 (t₂), 96.0 ± 2.5 (t₃). t_gel and t_int were 38.0 ± 7.8 s and 36.5 ± 5.6 s, respectively. No serious adverse events were recorded and no patient suffered airway trauma.

Conclusion:

I-gel insertion in spontaneous ventilation secures the airway before achieving fiberoptic intubation without the occurrence of adverse events. More studies might be necessary in order to confirm the results presented, but we consider that the technique described is a safe and effective alternative to classic OTI with FOB in spontaneously breathing patients with predicted difficult airway.

Blind Intubation through Self-pressurized, Disposable Supraglottic Airway Laryngeal Intubation Masks

Background

Supraglottic airway devices commonly are used for securing the airway during general anesthesia. Occasionally, intubation with an endotracheal tube through a supraglottic airway is indicated. Reported success rates for blind intubation range from 15 to 97%. The authors thus investigated as their primary outcome the fraction of patients who could be intubated blindly with an Air-Qsp supraglottic airway device (Mercury Medical, USA). Second, the authors investigated the influence of muscle relaxation on air leakage pressure, predictors for failed blind intubation, and associated complications of using the supraglottic airway device.

Methods

The authors enrolled 1,000 adults having elective surgery with endotracheal intubation. After routine induction of general anesthesia, a supraglottic airway device was inserted and patients were ventilated intermittently. Air leak pressure was measured before and after full muscle relaxation. Up to two blind intubation attempts were performed.

Results

The supraglottic airway provided adequate ventilation and oxygenation in 99% of cases. Blind intubation succeeded in 78% of all patients (95% CI, 75 to 81%). However, the success rate was inconsistent among the three centers (P &lt; 0.001): 80% (95% CI, 75 to 85%) at the Institute of Anesthesia and Pain Therapy, Kantonsspital Winterthur, Winterthur, Switzerland; 41% (95% CI, 29 to 53%) at the Department of Anesthesiology and Intensive Therapy, Medical University of Lodz, Lodz, Poland; and 84% (95% CI, 80 to 88%) at the Institute of Anesthesiology, University Hospital Zurich, Zurich, Switzerland. Leak pressure before relaxation correlated reasonably well with air leak pressure after relaxation.

Conclusions

The supraglottic airway device reliably provided a good airway and allowed blind intubation in nearly 80% of patients. It is thus a reasonable initial approach to airway control. Muscle relaxation can be used safely when unparalyzed leak pressure is adequate.

Supraglottic Airway Devices: the Search for the Best Insertion Technique or the Time to Change Our Point of View?

In the crowded world of supraglottic airway devices (SADs), many papers compare the easiness of insertion based on the different endpoints of an operator's satisfaction: first pass success, ventilation effectiveness, complications and morbidity. Proseal LMA^™ (Laryngeal Mask Airway, Teleflex Medical, Dublin, Ireland) has been extensively studied because on one hand it has a steeper learning curve and more complex insertion when compared with other SADs and on the other hand many alternative techniques are available to facilitate insertion. This research is part of a larger body of studies exploring the issue that some devices are more difficult to insert because of many features related to sizing, constructive material, airway conduit and cuff design, performance and last but not least experience. Nevertheless, the biggest question might be the search for a systematic categorization of insertion difficulty features and identification of criteria allowing the choice for the best device and consequently for the best insertion technique. Given that, as a result of many intrinsic characteristics of the device we are using, insertion might become the secondary issue to be considered only after we clearly identify what makes it difficult, and to be counterbalanced on the results we expect from the device, performance we can achieve and degree of airway protection it could grant. The aim of this narrative review is to consider which factors might affect or condition SAD insertion difficulty and to try identifying some criteria addressing physicians pertaining to the use of SADs in clinical practice.

Comparison of the ETView Single Lumen and Macintosh laryngoscopes for endotracheal intubation in an airway manikin with immobilized cervical spine by novice paramedics: A randomized crossover manikin trial

CONTEXT

Management of the airway of a trauma victim is considered challenging. Various approaches have been described to achieve airway control in this setup; many of them include video-assited viewing of the larynx during intubation. ETView Single Lumen (SL) is a novice single-use endotracheal tube equiped with a video camera and a light source at its distal tip. Its use was previously described in seeral clinical and training setups.

OBJECTIVE

The aim was to evaluate the efficacy of the VivaSight SL compared with classic direct laryngoscopy performed with a Macintosh blade in a manikin-simulated trauma setup presenting various degrees of airway challenge when performed by inexperienced physicians.

DESIGN, SETTING, PARTICIPANTS

This was prospective, randomized, crossover, manikin trial. After short training on the ETView system, 67 novice paramedics attempted to perform oral intubation using both standard direct laryngoscopy (MAC group) and the VivaSight SL endotracheal tube (ETView group) in a randomized order on manikins in 3 increasingly more difficult scenarios (simple intubation, cervical spine manual stabilization, and with cervical collar in place).

OUTCOME MEASURE

Overall success rate, time to intubation, number of intubation attempts, laryngeal view grade, dental compression, and overall participant satisfaction were monitored.

RESULTS

Duration of intubation and number of attempts were significantly superior in the ETView group in the latter 2 more challenging scenarios. All other parameters showed superiority to the ETView group in all 3 scenarios.

CONCLUSION

The VivaSight SL system performed better in a complex scenario of airway management of a trauma victim in need for cervical spine stabilization performed by novice caregivers compared to standard direct laryngoscopy and should be considered in this clinical setup.

The i-gel Supraglottic Airway as a Conduit for Fibreoptic Tracheal Intubation – A Randomized Comparison with the Single-use Intubating Laryngeal Mask Airway and CTrach Laryngeal Mask in Patients with Predicted Difficult Laryngoscopy

Fibreoptic intubation through a supraglottic airway is an alternative plan for airway management in difficult or failed laryngoscopy. The aim of this study was to compare three supraglottic airways as conduits in patients with at least one predictor for difficult laryngoscopy. The i-gel was compared with the single-use intubating laryngeal mask airway (sILMA) and CTrach laryngeal mask in 120 adult patients scheduled for elective surgeries under general anaesthesia using a prospective, randomized and single-blinded design. Primary outcome was success rate of tracheal intubation through the device, while secondary outcomes were times required for device insertion and tracheal tube placement, fibreoptic scores and the incidence of perioperative complications and postoperative complaints. The success rates showed no statistical difference between devices (i-gel 100%, CTrach 97.5%, ILMA 95%). Insertion time was shortest for the i-gel (12.4 s) compared with ILMA (19.3 s) and CTrach (24.4 s). Intubation time was shorter in the i-gel group (29.4 s) in comparison with the CTrach (39.8 s, p<0.05) and sILMA (51.9 s, p<0.001) groups. Best fibreoptic scores were observed also in the i-gel group. In total, 24 patients (20%) presented with difficult laryngoscopy. The i-gel showed significantly shorter times for insertion and fibreoptic intubation than the other two devices in this group. No difference was observed in the incidence of postoperative complaints. The i-gel is a suitable alternative to the sILMA and CTrach for fibrescope-guided tracheal intubation. Shorter insertion and intubation times with the i-gel may provide advantage in case of difficult oxygenation.

All India Difficult Airway Association 2016 guidelines for the management of unanticipated difficult tracheal intubation in adults

The All India Difficult Airway Association (AIDAA) guidelines for management of the unanticipated difficult airway in adults provide a structured, stepwise approach to manage unanticipated difficulty during tracheal intubation in adults. They have been developed based on the available evidence; wherever robust evidence was lacking, or to suit the needs and situation in India, recommendations were arrived at by consensus opinion of airway experts, incorporating the responses to a questionnaire sent to members of the AIDAA and the Indian Society of Anaesthesiologists. We recommend optimum pre-oxygenation and nasal insufflation of 15 L/min oxygen during apnoea in all patients, and calling for help if the initial attempt at intubation is unsuccessful. Transnasal humidified rapid insufflations of oxygen at 70 L/min (transnasal humidified rapid insufflation ventilatory exchange) should be used when available. We recommend no more than three attempts at tracheal intubation and two attempts at supraglottic airway device (SAD) insertion if intubation fails, provided oxygen saturation remains ≥ 95%. Intubation should be confirmed by capnography. Blind tracheal intubation through the SAD is not recommended. If SAD insertion fails, one final attempt at mask ventilation should be tried after ensuring neuromuscular blockade using the optimal technique for mask ventilation. Failure to intubate the trachea as well as an inability to ventilate the lungs by face mask and SAD constitutes 'complete ventilation failure', and emergency cricothyroidotomy should be performed. Patient counselling, documentation and standard reporting of the airway difficulty using a 'difficult airway alert form' must be done. In addition, the AIDAA provides suggestions for the contents of a difficult airway cart.

Comparison of blind intubation through supraglottic devices and direct laryngoscopy by novices: a simulation manikin study

OBJECTIVE

This study aimed to compare intubation performance between blind intubation through supraglottic airway devices and direct laryngoscopy by novices under manikin simulation. We hypothesized that the intubation time by novices using supraglottic airway devices was superior to that with the Macintosh laryngoscope (MCL).

METHODS

A prospective, randomized crossover study was conducted with 95 participants, to evaluate i-gel, air-Q, LMA Fastrach, and MCL devices. Primary outcomes were the intubation time and the success rate for intubation.

RESULTS

The i-gel showed the shortest insertion and tube passing time among the four devices; the i-gel and air-Q also showed the shortest total intubation time (all P<0.0083; i-gel vs. air-Q, P=0.03). The i-gel and MCL showed the highest cumulative success rate (all P<0.0083; i-gel vs. MCL, P=0.12).

CONCLUSION

Blind intubation through the i-gel showed almost equal intubation performance compared to direct laryngoscopy.

Fiberoptic-guided intubation after insertion of the i-gel airway device in spontaneously breathing patients with difficult airway predicted: a prospective observational study

STUDY OBJECTIVE

To assess the viability of performing fiberoptic-guided orotracheal intubation through the i-gel airway device previously inserted in spontaneously breathing patients with predicted difficult airway to achieve a patent airway.

DESIGN

Prospective observational study.

SETTING

Operating room in a tertiary care hospital.

PATIENTS

Eighty-five adult patients with at least 3 difficult airway predictors or difficult airway management history were included.

INTERVENTIONS

The i-gel device was inserted in spontaneous ventilation under oropharyngeal local anesthesia and sedation. After checking the adequate ventilation through the i-gel with capnography curve, general anesthesia was induced to introduce the endotracheal tube guided by fiberoptic bronchoscope.

MEASUREMENTS

We recorded the i-gel insertion time (tgel), intubation time (tint), and O₂ saturation in pulse oximetry in different moments: basal (t0), after 3 minutes of preoxygenation with a face mask at 100% fraction of inspired O₂ (t1), after i-gel mask insertion (t2), and after intubation (t3). Adverse events during the procedure were also recorded, and patient discomfort was questioned.

MAIN RESULTS

All patients were successfully intubated. O₂ saturation in pulse oximetry values were (mean±SD): 96.9±1.22 (t0), 99.0±0.85 (t1), 96.2±2.37 (t2), and 96.0±2.54 (t3). tgel and tint were 38.0±7.76 seconds and 36.5±5.55 seconds (mean±SD), respectively. No serious adverse events were recorded, and no patient suffered airway damage. Visual analogue scale for patient discomfort was 2 (interquartile range, 1-3).

CONCLUSIONS

i-gel insertion in spontaneously breathing patients avoids the "cannot ventilate" scenario. The subsequent fiberoptic-guided intubation through the i-gel is a safe and effective technique. More studies might be necessary to confirm the results presented, but we consider that the technique described is an adequate alternative to classic orotracheal intubation with fiberoptic bronchoscope in spontaneous ventilation for certain patients with predicted difficult airway.

Intubation Success through I-Gel® and Intubating Laryngeal Mask Airway® Using Flexible Silicone Tubes: A Randomised Noninferiority Trial

Introduction. The study aims to test whether flexible silicone tubes (FST) improve performance and provide similar intubation success through I-Gel as compared to ILMA. Our trial is registered in CTRI and the registration number is "CTRI/2016/06/006997." Methods. One hundred and twenty ASA status I-II patients scheduled for elective surgical procedures needing tracheal intubation were randomised to endotracheal intubation using FST through either I-Gel or ILMA. In the ILMA group (n = 60), intubation was attempted through ILMA using FST and, in the I-Gel group (n = 60), FST was inserted through I-Gel airway. Results. Successful intubation was achieved in 36.67% (95% CI 24.48%-48.86%) on first attempt through I-Gel (n = 22/60) compared to 68.33% (95% CI 56.56%-80.1%) in ILMA (n = 41/60) (p = 0.001). The overall intubation success rate was also lower with I-Gel group [58.3% (95% CI 45.82%-70.78%); n = 35] compared to ILMA [90% (95% CI 82.41%-97.59%); n = 54] (p < 0.001). The number of attempts, ease of intubation, and time to intubation were longer with I-Gel compared to ILMA. There were no differences in the other secondary outcomes. Conclusion. The first pass success rate and overall success of FST through an I-Gel airway were inferior to those of ILMA.

Effect of head position on the success rate of blind intubation using intubating supraglottic airway devices

BACKGROUND

To evaluate the effect of head position on the performance of intubating supraglottic airway devices, we compared the success rate of blind intubation in the head-elevated and the pillowless head positions with the LMA Fastrach and the air-Q, and the change of glottic visualization through the air-Q.

METHODS

We assigned 193 patients to two groups according to the device used and subgrouped by head position used for intubation: Fastrach/pillowless, Fastrach/head-elevated, air-Q/pillowless, and air-Q/head-elevated. Blind intubation through the Fastrach or the air-Q was attempted up to twice after induction of general anesthesia. Before the attempt at blind intubation with the air-Q, the percentage of glottic opening (POGO) score was also fiberscopically evaluated at the outlet of the device in both head positions in a cross-over fashion.

RESULTS

The Fastrach significantly facilitated blind intubation compared with the air-Q in both the pillowless and head-elevated positions: 87.2% in Fastrach/pillowless vs 65.9% in air-Q/pillowless (P=.048), 90% in Fastrach/head-elevated vs 53.7% in air-Q/head-elevated (P<.001). The head-elevated position did not significantly affect the success rate of blind intubation for either device (P=.97 in Fastrach, P=.37 in air-Q). Although the head-elevated position significantly improved the POGO score from the median (10-90 percentile) 60% (0-100%) in the pillowless position to 80% (0-100%) (P=.008), it did not contribute to successful blind intubation with the air-Q.

CONCLUSION

Although the head-elevated position improved glottic visualization in the air-Q, the head position had minimal influence on the success rate of blind intubation with either the Fastrach or the air-Q.

Difficult Airway Society 2015 guidelines for management of unanticipated difficult intubation in adults

These guidelines provide a strategy to manage unanticipated difficulty with tracheal intubation. They are founded on published evidence. Where evidence is lacking, they have been directed by feedback from members of the Difficult Airway Society and based on expert opinion. These guidelines have been informed by advances in the understanding of crisis management; they emphasize the recognition and declaration of difficulty during airway management. A simplified, single algorithm now covers unanticipated difficulties in both routine intubation and rapid sequence induction. Planning for failed intubation should form part of the pre-induction briefing, particularly for urgent surgery. Emphasis is placed on assessment, preparation, positioning, preoxygenation, maintenance of oxygenation, and minimizing trauma from airway interventions. It is recommended that the number of airway interventions are limited, and blind techniques using a bougie or through supraglottic airway devices have been superseded by video- or fibre-optically guided intubation. If tracheal intubation fails, supraglottic airway devices are recommended to provide a route for oxygenation while reviewing how to proceed. Second-generation devices have advantages and are recommended. When both tracheal intubation and supraglottic airway device insertion have failed, waking the patient is the default option. If at this stage, face-mask oxygenation is impossible in the presence of muscle relaxation, cricothyroidotomy should follow immediately. Scalpel cricothyroidotomy is recommended as the preferred rescue technique and should be practised by all anaesthetists. The plans outlined are designed to be simple and easy to follow. They should be regularly rehearsed and made familiar to the whole theatre team.

I-gel Versus LMA-Fastrach Supraglottic Airway for Flexible Bronchoscope-Guided Tracheal Intubation Using a Parker (GlideRite) Endotracheal Tube: A Randomized Controlled Trial

BACKGROUND

The I-gel (IG) supraglottic airway device is a reliable way to establish an airway. Its large ventilation lumen allows for easy passage of an endotracheal tube. With the use of a flexible bronchoscope, the IG offers a good visualization of the laryngeal inlet. This prospective randomized study aims to compare the success rate of flexible bronchoscope-guided tracheal intubation using either the IG or the LMA-Fastrach (FT) laryngeal masks.

METHODS

One hundred twenty patients requiring general anesthesia were randomized to 1 of the 2 study groups: IG or FT. After anesthesia induction, the assigned laryngeal mask was inserted to obtain adequate ventilation. We then proceeded to a flexible bronchoscope-guided intubation through the supraglottic device. Tracheal intubation and laryngeal mask insertion success rates were noted, as well as the time required for these manipulations. The view of the laryngeal inlet was graded for each intubation attempt.

RESULTS

Sixty patients were assigned to each study group. The intubation success rates were similar between the IG and the FT groups (100 % vs 95.0 % at first attempt; P = 0.12). The times required for tracheal intubation were significantly lower in the IG group (30 ± 11 seconds vs 50 ± 21 seconds; P < 0.0001). Glottic visualization was better in the IG group, with a significantly higher percentage of grade 1 visualization (63.3% vs 3.3%; P < 0.0001) and a lower percentage of grade 3 visualization (1.7% vs 60.0%; P < 0.0001), than that in the FT group.

CONCLUSIONS

The use of the IG supraglottic airway device as a conduit for flexible bronchoscope-guided tracheal intubation results in a success rate equivalent to the use of the LMA-FT. However, the IG allows for shorter intubation times and a better visualization of the glottic opening compared with the LMA-FT.

Randomized Comparison of Actual and Ideal Body Weight for Size Selection of the Laryngeal Mask Airway Classic in Overweight Patients

Size selection of the laryngeal mask airway (LMA) Classic based on actual body weight remains a common practice. However, ideal body weight might allow for a better size selection in obese patients. The purpose of our study was to compare the utility of ideal body weight and actual body weight when choosing the appropriate size of the LMA Classic by a randomized clinical trial. One hundred patients with age 20 to 70 yr, body mass index ≥25 kg/m(2), and the difference between LMA sizes based on actual weight and ideal weight were allocated to insert the LMA Classic using either actual body weight or ideal body weight in a weight-based formula for size selection. After insertion of the device, several variables including insertion parameters, sealing function, fiberoptic imaging, and complications were investigated. The insertion success rate at the first attempt was lower in the actual weight group (82%) than in the ideal weight group (96%), even it did not show significant difference. The ideal weight group had significantly shorter insertion time and easier placement. However, fiberoptic views were significantly better in the actual weight group. Intraoperative complications, sore throat in the recovery room, and dysphonia at postoperative 24 hr occurred significantly less often in the ideal weight group than in the actual weight group. It is suggested that the ideal body weight may be beneficial to the size selection of the LMA Classic in overweight patients (Clinical Trial Registry, NCT 01843270).

The novel intubating laryngeal tube (iLTS-D) is comparable to the intubating laryngeal mask (Fastrach) - a prospective randomised manikin study

Background

Supraglottic devices are helpful for inexperienced providers who perform ventilation in emergency situations. Most supraglottic devices do not allow secondary tracheal intubation through the device. The novel intubating laryngeal tube (iLTS-D®) and the intubating laryngeal mask (Fastrach™) are devices that offer supraglottic ventilation and secondary tracheal intubation.

Methods

We evaluated the novel iLTS-D and compared it to the established Fastrach using a manikin-based study. Participants used both devices in a randomised order. The participants conducted four consecutive trials on a manikin. One trial was composed of the following procedures. First, participants ventilated the manikin using either iLTS-D or Fastrach. ‘Time to ventilation’, success rates and number of attempts were recorded for the supraglottic device. Second, participants intubated the manikin through the previously inserted supraglottic device. ‘Time to tracheal ventilation’, success rate and tube localisation were recorded. The primary endpoint was the results of the final fourth trial, which mirrored the standardised training of trials 1, 2 and 3.

Results

A total of 64 participants were enrolled. All of the participants successfully inserted both devices on their first attempt in trial 4. Fastrach was applied 1 s faster in trial 4 than the iLTS-D (median ‘time to ventilation’ Fastrach: 13.5 s., iLTS-D: 14.5 s., p = 0.04). All participants successfully intubated through both devices in trial 4. There was no difference in ‘time to tracheal ventilation’ by tracheal intubation between either device (median ‘time to tracheal ventilation’: Fastrach: 14.0 s., iLTS-D: 14.0 s., p = 0.16).

Conclusion

The iLTS-D performed similarly to the ILMA in insertion and intubation times in a manikin setting.

Airway management evolution - in a search for an ideal extraglottic airway device

Extraglottic airway devices (EADs) are commonly used equipment for airway maintenance during elective procedures under general anaesthesia. They may be used also in other indications such as conduit for tracheal intubation or rescue airway device in prehospital medicine. Current classifications of the EADs lack systematic approach and therefore classification according to the sealing sites and sealing mechanisms is suggested in this review article. Modern EADs are disposable, latex-free devices made of plastic materials most commonly from polyvinylchloride (PVC). The bowl of uncuffed sealers is manufactured from different materials such as thermoplastic elastomers or ethylene-vinyl-acetate co-polymer. EADs create various physical forces exerted on the adjacent tissues which may contribute to different sealing characteristic of particular device or to variable incidence of postoperative complications. Desired features of an ideal EAD involve easy insertion, high insertion success rate even by inexperienced users, protection against aspiration of gastric contents and low incidence of postoperative complications such as sore throat, hoarseness, cough or swallowing difficulties.

A comparison of fibreoptic-guided tracheal intubation through the Ambu ® Aura-i ™, the intubating laryngeal mask airway and the i-gel ™: a manikin study

We compared the Aura-i(™) , intubating laryngeal mask airway and i-gel(™) as conduits for fibreoptic-guided tracheal intubation in a manikin. Thirty anaesthetists each performed two tracheal intubations through each device, a total of 180 intubations. The median (IQR [range]) time to complete the first intubation was 40 (31-50 [15-162]) s, 37 (34-48 [25-75]) s and 28 (22-35 [14-59]) s for the Aura-i, intubating laryngeal mask airway and i-gel, respectively. Tracheal intubation through the i-gel was the quickest (p < 0.01). Resistance to railroading of the tracheal tube over the fibrescope was significantly greater through the Aura-i compared with the intubating laryngeal mask airway and the i-gel (p = 0.001). There were no failures to intubate through the intubating laryngeal mask airway or the i-gel but six intubation attempts through the Aura-i were unsuccessful, in five owing to a railroading failure and in one owing to accidental oesophageal intubation. We conclude that the Aura-i does not perform as well as the intubating laryngeal mask airway or the i-gel as an adjunct for performing fibreoptic-guided tracheal intubation.

Comparison of supraglottic devices i-gel(®) and LMA Fastrach(®) as conduit for endotracheal intubation

Background and Aims:

i-gel^®, a recently introduced supraglottic airway device (SAD) has been claimed to be an efficient supraglottic airway. It can also be used as a conduit for endotracheal intubation. However, LMA Fastrach^® frequently used for this purpose; hence in this randomized study, success rate of blind tracheal intubation through two different SADs i-gel^® and LMA Fastrach^® was evaluated. The complications if any were also studied.

Methods:

A total of 100 patients undergoing elective surgery under general anaesthesia were randomised in two groups comprising of 50 patients each to tracheal intubation using either i-gel (I group) or LMA Fastrach (F group). After induction of anaesthesia SAD was inserted and on achieving adequate ventilation with the device, blind tracheal intubation was attempted through the SAD. Success at first-attempt and overall tracheal intubation success rates were evaluated, and tracheal intubation time was measured. Data were analysed using IBM SPSS Statistics 20.0 software (Statistical Package for Social Sciences by International Business Machines Corporation). P < 0.05 was considered as statistically significant.

Results:

There was no difference in the incidence of adequate ventilation with either of the SAD. The success rate of tracheal intubation in first attempt was 66% in Group I and 74% in Group F, while overall success rate of tracheal intubation was 82% in Group I when compared to 96% in Group F. Time taken for successful tracheal intubation through LMA Fastrach was lesser (20.96 s) when compared to i-gel (24.04 s). Complication rates were statistically similar in both the groups.

Conclusion:

i-gel^® is a better device for rescue ventilation due to its quick insertion but an inferior intubating device in comparison to LMA Fastrach^®.

The difficult airway with recommendations for management--part 1--difficult tracheal intubation encountered in an unconscious/induced patient

Background

Previously active in the mid-1990s, the Canadian Airway Focus Group (CAFG) studied the unanticipated difficult airway and made recommendations on management in a 1998 publication. The CAFG has since reconvened to examine more recent scientific literature on airway management. The Focus Group’s mandate for this article was to arrive at updated practice recommendations for management of the unconscious/induced patient in whom difficult or failed tracheal intubation is encountered.

Methods

Nineteen clinicians with backgrounds in anesthesia, emergency medicine, and intensive care joined this iteration of the CAFG. Each member was assigned topics and conducted reviews of Medline, EMBASE, and Cochrane databases. Results were presented and discussed during multiple teleconferences and two face-to-face meetings. When appropriate, evidence- or consensus-based recommendations were made together with assigned levels of evidence modelled after previously published criteria.

Conclusions

The clinician must be aware of the potential for harm to the patient that can occur with multiple attempts at tracheal intubation. This likelihood can be minimized by moving early from an unsuccessful primary intubation technique to an alternative “Plan B” technique if oxygenation by face mask or ventilation using a supraglottic device is non-problematic. Irrespective of the technique(s) used, failure to achieve successful tracheal intubation in a maximum of three attempts defines failed tracheal intubation and signals the need to engage an exit strategy. Failure to oxygenate by face mask or supraglottic device ventilation occurring in conjunction with failed tracheal intubation defines a failed oxygenation, “cannot intubate, cannot oxygenate” situation. Cricothyrotomy must then be undertaken without delay, although if not already tried, an expedited and concurrent attempt can be made to place a supraglottic device.

i-gel™ supraglottic airway in clinical practice: a prospective observational multicentre study

BACKGROUND

The i-gel™ supraglottic airway device has been studied in randomized controlled studies, but it has not been evaluated in a large prospective patient cohort. Therefore, we performed this prospective multicentre observational study to evaluate success rates, airway leak pressure, risk factors for i-gel failure, and adverse events.

METHODS

With Ethics Committee approval and waiver of patients' consent, data about anaesthesia providers, patient characteristics, and the performance of the i-gel were recorded in five independent hospitals in Switzerland over a period of 24 months. We analysed success rates, leak pressures, adverse events, and risk factors for failure.

RESULTS

Data from 2049 i-gel uses were analysed. Patients' mean age was 47 (range 6-91) yr. The primary i-gel success rate without changing size was 93%; the overall success rate was 96%. Insertion was deemed very easy or easy in 92%. The mean airway leak pressure was 26 (8) cm H(2)O. The mean anaesthesia time was 67 (42) min. Risk factors associated with i-gel failure were males (P<0.001), impaired mandibular subluxation (P=0.01), poor dentition (P=0.02), and older age (P<0.01). Adverse events recorded were laryngeal spasms (n=25, 1.2%), blood stained airway devices (n=79, 3.9%), transient nerve damage (n=2, 0.1%), one case of transient vasovagal asystole, and one glottic haematoma.

CONCLUSIONS

The i-gel is a reliable supraglottic airway device failing in <5% and providing high airway leak pressures. Males, impaired mandibular subluxation, poor dentition, and older age are risk factors associated with primary device failure. Serious adverse events are rare.

Tracheal intubation through the I-gel™ supraglottic airway versus the LMA Fastrach™: a randomized controlled trial

BACKGROUND

The i-gel™ is a supraglottic airway device not requiring inflation of a cuff for lung ventilation. Its design allows for unobstructed passage of a tracheal tube and previous studies have demonstrated a favorable alignment with the glottic inlet. In this prospective randomized study, we compared the success rate of blind tracheal intubation using the i-gel and the laryngeal mask airway (LMA) Fastrach™.

METHODS

One hundred sixty patients requiring general anesthesia and airway management were randomized to tracheal intubation using the i-gel or the LMA Fastrach. After induction of general anesthesia, the allocated device was inserted and adequate lung ventilation was confirmed. Blind tracheal intubation was then attempted. First attempt and overall tracheal intubation success rates were evaluated and tracheal intubation times were measured.

RESULTS

Eighty patients were recruited in each study group. Successful tracheal intubation was obtained on the first attempt in 69% of patients with the i-gel and 74% of patients with the LMA Fastrach (95% confidence interval [CI] of difference, -9% to 19%, P = 0.60). The overall intubation success rate was lower using the i-gel than it was using the LMA Fastrach (73% vs 91%, 95% CI of difference, 7% to 31%, P < 0.0001).

CONCLUSIONS

On first attempts, successful blind tracheal intubation was obtained at comparable rates using the i-gel and the LMA Fastrach. However, when the first attempt was unsuccessful, subsequent attempts through the i-gel did not significantly increase tracheal intubation success rate. The LMA Fastrach yielded a higher overall intubation success rate.

Randomized trial comparing the i-gel™ and Magill tracheal tube with the single-use ILMA™ and ILMA™ tracheal tube for fibreoptic-guided intubation in anaesthetized patients with a predicted difficult airway

BACKGROUND

The i-gel™ is a single-use supraglottic airway device (SAD) that allows fibreoptic-guided tracheal intubation through the device. Until now, no prospective data for this procedure are available. Therefore, in a prospective randomized controlled trial, we evaluated fibreoptic-guided tracheal intubation with a standard Rüsch™ PVC tracheal tube (TT) through the i-gel™ compared with the single-use ILMA™ (sILMA™) TT through the sILMA™ in patients with a predicted difficult airway.

METHODS

With ethics committee approval and written informed consent, 160 patients were randomly assigned to either SAD. After placement of the SAD, a fibreoptic bronchoscope was introduced into the trachea as a railroad for the TT. Primary outcome variable was the first-attempt fibreoptic-guided intubation success rate. Secondary variables included time for insertion and intubation, airway leak pressures, fibreoptic view, and adverse events. Data are presented as mean (sd) or percentages. A P-value of < 0.05 was considered statistically significant.

RESULTS

Fibreoptic-guided intubation was successful at the first attempt in 76 patients (96%) using the i-gel™ and in 71 patients (90%) using the sILMA™ (P=0.21). Most of the failed intubations were rescued by conventional laryngoscopy. Airway leak pressure was higher for the sILMA™. There were no problems during removal of either type of SAD.

CONCLUSIONS

Fibreopic-guided tracheal intubation through the i-gel™ using a standard Rüsch™ Magill TT is successful and an alternative to the sILMA™ with the sILMA™ TT.