Stylet for reinforced laryngeal mask airway

Lightwand-Guided Insertion of Flexible Reinforced Laryngeal Mask Airway: Comparison with Standard Digital Manipulation Insertion

Background

The flexibility of the long flexometallic tube makes insertion of the flexible reinforced laryngeal mask airway (f-LMA) difficult. We compared the usefulness of rigid lightwand-guided f-LMA insertion with standard digital manipulation.

Material/Methods

Fifty-four patients (aged 19–70 years) were randomly divided into a control group (digital manipulation technique) or the lightwand group (lightwand-guided insertion technique). The insertion profiles, oropharyngeal leak pressure (OLP), peak inspiratory pressure (PIP), expiratory tidal volume, and ventilatory score were measured in patients with neutral, extension, rotation, flexion, and re-neutral head-neck positions in turn.

Results

The success rate and ease of insertion did not differ between groups, but the insertion time was longer in the lightwand group. The fiberoptic laryngeal view was significantly better in the lightwand group than in the control group. However, the OLP, PIP, expiratory tidal volume, and ventilatory scores were not significantly different between groups according to head-neck positions. The extension posture was associated with a significant negative effect on ventilation, but ventilation returned to initial levels with the other postures.

Conclusions

Lightwand-guided f-LMA insertion showed a better fiberoptic laryngeal view than standard digital manipulation, but no improvement in the ventilatory state was observed due to position. Therefore, lightwand-guided insertion could facilitate correct placement of the f-LMA, but it has limited clinical usefulness.

Comparison of insertion of the modified i-gel airway for oral surgery with the LMA Flexible: a manikin study

We previously modified the i-gel airway to enable its use in the field of oral and maxillofacial surgery and reported its fabrication methods. In general, the standard i-gel airway is quick to insert and has a high success rate, but the modified i-gel airway has yet to be assessed for these attributes. We, therefore, set out to compare the ease of insertion of the modified i-gel airway with the LMA Flexible to investigate the usefulness of the modified i-gel airway. The study participants, who included 20 new interns with no experience using either the LMA Flexible or the modified i-gel airway, inserted each device 3 times into an intubation practice manikin. The variables measured in this study were insertion time and rate of successful insertions. Mean insertion time over 3 attempts was significantly shorter for the modified i-gel™ airway (18.9 ± 4.7 seconds) than the LMA Flexible (24.9 ± 5.1 seconds, P < .001). The rate of successful insertions as a total of all 3 attempts was significantly higher for the modified i-gel airway (56/60 times, 93.3%) than the LMA Flexible (45/60 times, 75%; P = .012). When used by an inexperienced operator, the modified i-gel™ airway is faster and has a higher success rate than the LMA Flexible, suggesting that it can be easily manipulated during insertion.

An evaluation of the flexiguide introducer with the flexible laryngeal mask airway

Insertion of the flexible Laryngeal Mask Airway has been achieved by a variety of techniques. We have evaluated the Flexiguide for aiding introduction of a flexible Laryngeal Mask Airway in 100 anaesthetised patients. We were successful in establishing a clear airway on the first attempt on 84 (84%) occasions and within two attempts in 97 (97%). The positioning of the laryngeal mask airway was assessed by five measures and was optimally placed in 85% of cases and good in 96%. A clear airway was achieved in 92% of cases. Insertion of the flexible Laryngeal Mask Airway with the Flexiguide was easy in 82 (82%) and slightly difficult in 15 (15%) of cases. Removal of the Flexiguide from the device was easy in 95 (95%) of cases. Airway manoeuvres were used to assist airway placement in 55% of cases with jaw thrust being most common. Minor complications occurred in three (3%) patients: two coughed and one experienced minor tissue trauma during mask insertion. There were no complications associated with use of the Flexiguide during the procedure or after anaesthesia. The Flexiguide is a useful tool to assist insertion of the flexible Laryngeal Mask Airway and is associated with few complications.

The laryngeal mask airway: its features, effects and role

The laryngeal mask airway was designed as a new concept in airway management and has been gaining a firm position in anaesthetic practice. Numerous articles and letters about the device have been published in the last decade, but few large controlled trials have been performed. Despite widespread use, the definitive role of the laryngeal mask has yet to be established. In some situations, such as after failed tracheal intubation or in anaesthesia for patients undergoing laparoscopic or oral surgery, its use is controversial. There are a number of unresolved issues, for example the effect of the laryngeal mask on regurgitation and whether or not cricoid pressure prevents placement of the mask. We review the techniques of insertion, details of misplacement, and complications associated with the use of the laryngeal mask. We discuss the features and physiological effects of the device, including the changes in intra-cuff pressure during anaesthesia and effects on blood pressure, heart rate and intra-ocular pressure. We then attempt to clarify the role of the laryngeal mask in airway management during anaesthesia, based on the current knowledge, by discussing the advantages and disadvantages as well as the indications and contraindications of its use. Lastly we describe the use of the laryngeal mask in circumstances other than airway maintenance during anaesthesia: fibreoptic bronchoscopy, tracheal intubation through the mask and its use in cardiopulmonary resuscitation.