Overinflation of the cuff and pressure on the neck reduce the preventive effect of supraglottic airways on pulmonary aspiration: an experimental study in human cadavers

The case for a 3rd generation supraglottic airway device facilitating direct vision placement

Although 1st and 2nd generation supraglottic airway devices (SADs) have many desirable features, they are nevertheless inserted in a similar 'blind' way as their 1st generation predecessors. Clinicians mostly still rely entirely on subjective indirect assessments to estimate correct placement which supposedly ensures a tight seal. Malpositioning and potential airway compromise occurs in more than half of placements. Vision-guided insertion can improve placement. In this article we propose the development of a 3rd generation supraglottic airway device, equipped with cameras and fiberoptic illumination, to visualise insertion of the device, enable immediate manoeuvres to optimise SAD position, verify whether correct 1st and 2nd seals are achieved and check whether size selected is appropriate. We do not provide technical details of such a '3rd generation' device, but rather present a theoretical analysis of its desirable properties, which are essential to overcome the remaining limitations of current 1st and 2nd generation devices. We also recommend that this further milestone improvement, i.e. ability to place the SAD accurately under direct vision, be eligible for the moniker '3rd generation'. Blind insertion of SADs should become the exception and we anticipate, as in other domains such as central venous cannulation and nerve block insertions, vision-guided placement becoming the gold standard.

Recommendations for the evaluation and management of the anticipated and non-anticipated difficult airway of the Societat Catalana d'Anestesiologia, Reanimació i Terapèutica del Dolor, based on the adaptation of clinical practice guidelines and expert consensus

The Airway Division of the Catalan Society of Anaesthesiology, Intensive Care and Pain Management (SCARTD) presents its latest guidelines for the evaluation and management of the difficult airway. This update includes the technical advances and changes observed in clinical practice since publication of the first edition of the guidelines in 2008. The recommendations were defined by a consensus of experts from the 19 participating hospitals, and were adapted from 5 recently published international guidelines following an in-depth analysis and systematic comparison of their recommendations. The final document was sent to the members of SCARTD for evaluation, and was reviewed by 11 independent experts. The recommendations, therefore, are supported by the latest scientific evidence and endorsed by professionals in the field. This edition develops the definition of the difficult airway, including all airway management techniques, and places emphasis on evaluating and classifying the airway into 3 categories according to the anticipated degree of difficulty and additional safety considerations in order to plan the management strategy. Pre-management planning, in terms of preparing patients and resources and optimising communication and interaction between all professionals involved, plays a pivotal role in all the scenarios addressed. The guidelines reflect the increased presence of video laryngoscopes and second-generation devices in our setting, and promotes their routine use in intubation and their prompt use in cases of unanticipated difficult airway. They also address the increased use of ultrasound imaging as an aid to evaluation and decision-making. New scenarios have also been included, such as the risk of bronchoaspiration and difficult extubation Finally, the document outlines the training and continuing professional development programmes required to guarantee effective and safe implementation of the guidelines.

Flexion decreases the ventilation quality of the Ambu® AuraGain™ laryngeal mask in paralysed children: A prospective randomised crossover study

BACKGROUND

The influence of different head and neck positions on ventilation with the Ambu® AuraGain™ remains unevaluated in children. This study assessed the influence of different head and neck positions on ventilation with the AuraGain™ in paediatric patients.

METHODS

In this prospective, randomised crossover study, children ≤7 years of age who were scheduled for elective surgery under general anaesthesia were enrolled. An AuraGain™ was placed in all patients; mechanical ventilation was performed using a volume-controlled mode with a tidal volume of 10 mL/kg. Respiratory rate was adjusted to maintain a ETCO2 of 35-40 mm Hg. The oropharyngeal leak pressure, expiratory tidal volume, peak inspiratory pressure, ventilation score and fibreoptic bronchoscopic view score were assessed for the neutral head and neck position, and then for the flexed, extended and rotated head and neck positions in a random order.

RESULTS

Compared with the neutral position, the oropharyngeal leak pressure increased in the flexed position (P < .001), and decreased in the extended (P = .014) and rotated position (P = .002). The expiratory tidal volume and ventilation score were significantly reduced during flexion (all P < .005), and were comparable among the neutral, extended and rotated positions. The fibreoptic score improved in the extended and rotated position (all P < .001). Only the flexion ventilation score was lower compared with the neutral position (P = .014).

CONCLUSIONS

Clinically, the flexed head and neck positions negatively affected ventilation due to obstruction of the airway. Ventilation with AuraGain™ can be effectively performed with the head and neck in the neutral, extended and rotated position in paediatric patients.