Laryngeal mask, laryngeal tube, and Frova introducer in simulated difficult airway

New Devices, Innovative Technologies, and Non-Standard Techniques for Airway Management: A Narrative Review

A wide range of airway devices and techniques have been created to enhance the safety of airway management. However, airway management remains a challenge. All techniques are susceptible to failure. Therefore, it is necessary to have and know the greatest number of alternatives to treat even the most challenging airway successfully. The aim of this narrative review is to describe some new devices, such as video laryngeal masks, articulated stylets, and non-standard techniques, for laryngeal mask insertion and endotracheal intubation that are not applied in daily practice, but that could be highly effective in overcoming a difficulty related to airway management. Artificial intelligence and 3D technology for airway management are also discussed.

Efficacy of tracheal tube introducers and stylets for endotracheal intubation in the prehospital setting: a systematic review and meta-analysis

PURPOSE

Tracheal tube introducers and stylets remain some of the most widely used devices for aiding practitioners in performing endotracheal intubation (ETI). The purpose of this systematic review is to evaluate the efficacy of tracheal tube introducers and stylets for ETI in the prehospital setting.

METHODS

A literature search was conducted on the 2nd of March 2021 across PubMed, Embase (Ovid) and the Cochrane Central Register of Controlled Trials (CENTRAL) to identify relevant studies. Included studies had their data extracted and both a quality assessment and statistical analysis were performed.

RESULTS

The summary estimate of prehospital studies with video technology showed a statistically significant increase in first pass ETI success in favour of bougies (RR 1.15, CI 1.10-1.21, p < 0.0001). The summary estimates of prehospital studies without video technology and simulation studies with and without video technology showed no statistical difference between methods for first pass or overall ETI success. Some of the highest success rates were recorded by devices that incorporated video technology. Stylets lead to a shorter time to ETI while bougies were easier to use. Neither device was associated with a higher rate of ETI complications than the other.

CONCLUSION

Both tracheal tube introducers and stylets function as efficacious aids to intubation in the prehospital environment. Where video technology is available, bougies could offer a statistically significant advantage in terms of first pass ETI success. Where video technology is unavailable, a combination of clinical scenario, practitioner expertise and personal preference might ultimately guide the choice of device.

Comparison of Glidescope® Go™, King Vision™, Dahlhausen VL, I‑View™ and Macintosh laryngoscope use during difficult airway management simulation by experienced and inexperienced emergency medical staff: A randomized crossover manikin study

Background

In pre-hospital emergency care, video laryngoscopes (VLs) with disposable blades are preferably used due to hygienic reasons. However, there is limited existing data on the use of VLs with disposable blades by emergency medical staff. Therefore, the aim of this study was to compare the efficacy of four different VLs with disposable blades and the conventional standard Macintosh laryngoscope, when used by anesthetists with extensive previous experience and paramedics with little previous experience in endotracheal intubation (ETI) in a simulated difficult airway.

Methods

Fifty-eight anesthetists and fifty-four paramedics participated in our randomized crossover manikin trial. Each performed ETI with the new Glidescope^® Go^™, the Dahlhausen VL, the King Vision^™, the I-View^™ and the Macintosh laryngoscope. “Time to intubate” was the primary endpoint. Secondary endpoints were “time to vocal cords”, “time to ventilate”, overall success rate, number of intubation attempts and optimization maneuvers, Cormack-Lehane score, severity of dental compression and subjective impressions.

Results

The Glidescope^® Go^™, the Dahlhausen VL and the King Vision^™ provided superior intubation conditions in both groups without affecting the number of intubation attempts or the time required for successful intubation. When used by anesthetists with extensive experience in ETI, the use of VLs did not affect the overall success rate. In the hands of paramedics with little previous experience in ETI, the failure rate with the Macintosh laryngoscope (14.8%) decreased to 3.7% using the Glidescope^® Go^™ and the Dahlhausen VL. Despite the advantages of hyperangulated video laryngoscopes, the I-View^™ performed worst.

Conclusions

VLs with hyperangulated blades facilitated ETI in both groups and decreased the failure rate by an absolute 11.1% when used by paramedics with little previous experience in ETI. Our results therefore suggest that hyperangulated VLs could be beneficial and might be the method of choice in comparable settings, especially for emergency medical staff with less experience in ETI.

Endotracheal Intubation of Rabbits Using a Polypropylene Guide Catheter

Endotracheal intubation in rabbits can be challenging due to their unusual anatomy. Achieving a patent airway during anesthesia is critical for the avoidance of airway obstruction, prevention of gastric tympany, and to allow ventilatory support. Due to the difficulty of intubation, alternative methods such as the use of laryngeal mask airways or laryngeal tubes have been explored. However, these methods do not result in direct access to the trachea and thus may present a risk for development of complications. In addition, lack of direct intubation of the trachea can result in personnel exposure to waste anesthetic gases. Numerous methods for endotracheal intubation have been described, including blind placement, use of a fiberoptic laryngoscope or endoscope, and cricoid placement. Despite these numerous publications, many still struggle to achieve success. Here we provide a detailed description of an intubation technique that can be taught with minimal training with a short time to proficiency. Briefly, after administration of injectable anesthesia and proper positioning of the rabbit, a polypropylene catheter is placed into the trachea by direct visualization using a laryngoscope. The catheter is then used as a guide to direct the endotracheal tube into the trachea. This method allows for intubation without the need for expensive equipment and can be performed by a single individual without the need for an assistant. In conclusion, this technique can be easily taught and performed at very little cost in any clinical or research setting.

Exchange of supraglottic airways for endotracheal tube using the Eschmann Introducer during simulated child resuscitation: A randomized study comparing 4 devices

BACKGROUND

The aim of this study was to examine the application of the Eschmann tracheal tube introducer (ETTI) with 4 types of supraglottic airway devices (SADs) using a child-manikin.

METHODS

A total of 79 paramedics were asked to exchange the 4 SADs for an endotracheal tube with the ETTI in 3 different scenarios using a randomized crossover study format: normal airway without chest compression; normal airway with uninterrupted chest compression; and difficult airway with uninterrupted chest compression. The primary outcome was time to SAD exchange, with the secondary outcome measuring the success of SAD exchange. Each attempt was assessed by a trained assistant.

RESULTS

The mean exchange times for LMA, Cobra PLA, Air-Q, and SALT were as follows: 21, 23, 21, and 18, respectively for Scenario A; 23, 27, 22.5, and 21 for Scenario B; and 23, 28, 23, and 23 for Scenario C. The percent efficacy of SADs exchange with LMA, Cobra PLA, Air-Q and SALT were 98.7%, 94.9%, 100%, and 100% for scenario A; 98.7%, 88.6%, 98.7%, and 97.5% for scenario B; and 93.7%, 87.3%, 94.9%, and 93.7% for scenario C.

CONCLUSIONS

In this model of pediatric resuscitation, the SAD exchange using an ETTI has (LMA, Cobra PLA, Air-Q and SALT) proved to be effective in paramedics with no previous experience. Furthermore, experimental findings indicated that SAD exchange can be achieved without interrupting chest compression.

Comparison of Xenon with LED illuminant in difficult and inhalation injury airway scenario: A randomized crossover manikin study

PURPOSE

The purpose of this study was to compare the effectiveness of a Xenon halogen with a light-emitting diode (LED) laryngoscope light handle in a difficult airway scenario, as well as in an inhalation injury airway scenario that combines a difficult airway and a limited view.

METHODS

We recruited forty-two anesthetists into a randomized crossover trial. Each performed tracheal intubation (TI) with a Xenon halogen and a LED light handle in the two manikin scenarios. The primary endpoint was the "time to intubate". Other endpoints were the "time to vocal cords", the "time to ventilate", the rate of successful intubation, the number of intubation attempts, the Cormack-Lehane score, the number of optimization maneuvers, the number of audible dental click sounds indicating dental damage and subjective impressions.

RESULTS

In the difficult airway scenario, no significant differences in the recorded intubation times were observed. In the inhalation injury airway scenario, the intubation times were significantly shorter using the LED light handle. Regarding the subjective values, the LED illuminant enabled a significant better view and illumination of the oropharyngeal space and the vocal cords, in both manikin scenarios.

CONCLUSION

The LED laryngoscope light handle did not affect the recorded intubation times in the simulated difficult airway scenario, but provided significant advantages in the inhalation injury airway scenario that combines a difficult airway with a limited view caused by a sooted pharynx. We therefore hypothesize, that the LED illuminant might be beneficial in the airway management of burn patients with severe inhalation injury.