Extraglottic Airway Devices Research Articles

The Emergency Airway: Noteworthy Airway Articles: From DSI to Extraglottic Airway Devices

The Emergency Airway: Noteworthy Airway Articles: From DSI to Extraglottic Airway Devices

Larynxtubus II

Difficult airway situations both expected and unexpected, present major challenges to every anesthesiologist, especially in pediatric anesthesia. However, the integration of extraglottic airway devices, such as the laryngeal mask, into the algorithm of difficult airways has improved the handling of difficult airway situations. A device for establishing a supraglottic airway, the laryngeal tube (LT), was introduced in 1999. The LT is an extraglottic airway designed to secure a patent airway during either spontaneous breathing or controlled ventilation. The design of the device has been revised several times and a further development is the LTSII/LTS-D, which provides an additional channel for the insertion of a gastric drain tube. This article reports on the successful use of the LTSII in 12 children aged from 2 days to 6 years when endotracheal intubation, alternative mask or laryngeal mask ventilation failed. Use of the LTSII was associated with a high level of success, securing the airway when other techniques had failed. The potential advantage of the LTSII over the standard LT is an additional suction port, which allows gastric tube placement and can be used as an indirect indicator of correct placement. With a modified insertion technique using an Esmarch manoeuvre, placement was simple and fast to perform. In emergency situations when direct laryngoscopy fails or is too time-consuming the LTSII tube is recommended as an alternative device to secure the airway. As with all extraglottic airway devices, familiarity and clinical experience with the respective device and the corresponding insertion technique are essential for safe and successful use, especially in emergency situations.

Comparison of Three Extraglottic Airway Devices

Extraglottic airway devices (EGDs) are valuable tools for emergency medical services providers during cardiopulmonary resuscitation (CPR). Researchers

Colour coding: a must for extraglottic airway devices

We read with interest the recent letters highlighting the problems associated with ambiguous or inaccurate colour coding of gas cylinders [1, 2]. When correctly applied, colour coding plays an important role in avoiding mistakes due to human error [3], as critical information about the device is instantly available. Unfortunately, colour coding has only been introduced for gas cylinders [4], intravenous cannulas and needles [5].We consider that extraglottic airway devices should be added to this woefully short list.

Extraglottische Atemwegshilfen auf der Intensivstation

Extraglottic airway devices (EGA) are not only used in routine anaesthesia practice, they also have a distinct value for in-hospital and out-of-hospital difficult airway management. In the environment of the intensive care unit (ICU) EGA are not used on a regular basis. However, expertise and knowledge regarding EGA coming from the operating theatre or the out-of-hospital setting may also be of value for the ICU setting. This review presents the potential indications for EGA on the ICU for the management of difficult airway situations as well as during percutaneous tracheotomy. Furthermore, the possible advantages of EGA during postoperative recovery from anaesthesia as well as termination of controlled ventilation for intensive care patients are discussed.

Pilot Study of the Air-Q Intubating Laryngeal Airway in Clinical Use

The air-Q Intubating Laryngeal Airway (ILA) is a newly introduced extraglottic airway device. In this pilot study, we evaluated its use as a routine airway device during positive pressure ventilation. Ease of endotracheal intubation through the device was also assessed. Fifty-nine ASA I and II patients undergoing elective surgery received an air-Q ILA and an endotracheal tube where indicated. Insertion, ventilation and intubation characteristics were noted, as well as throat morbidity and occurrence of adverse events. An air-Q ILA was successfully inserted in 100% of patients. Mean leak pressure was 19 +/- 5 cmH2O. Endotracheal intubation was indicated in 19 patients and successful in 58% on the first attempt and 74% in total. Ten percent of the study patients were noted to have dysphagia. One patient was diagnosed with bilateral lingual nerve injury but made a complete recovery in four weeks. The air-Q ILA is an adequate extraglottic airway device in terms of insertion and ventilation. However the proposed advantage of ease of endotracheal intubation requires further investigation.

Lingual Nerve Injury: a complication associated with the classic laryngeal mask airway?

Cranial nerve injuries are well-recognized complications of laryngoscopy and tracheal intubation and face mask ventilation. Recently, these have also been reported in association with extraglottic airway devices. Its diagnosis is clinical and it has a good prognosis, with resolution of the symptoms within a few weeks to months. The frequency of cranial nerve injuries can be reduced by avoiding insertion trauma, using appropriate sizes, minimizing cuff volume, and early identification and correction of malposition. We present a case of lingual nerve injury that was associated with use of the classic laryngeal mask airway during bilateral varicose vein stripping and perforator ligation under general, balanced anesthesia.

The Laryngeal Mask Airway SupremeTM– a single use laryngeal mask airway with an oesophageal vent. A randomised, cross‐over study with the Laryngeal Mask Airway ProSealTM in paralysed, anaesthetised patients

The LMA Supreme is a new extraglottic airway device which brings together features of the LMA ProSeal, Fastrach and Unique. We test the hypothesis that ease of insertion, oropharyngeal leak pressure, fibreoptic position and ease of gastric tube placement differ between the LMA ProSeal and the LMA Supreme in paralysed anesthetised patients. Ninety-three females aged 19-71 years were studied. Both devices were inserted into each patient in random order. Two attempts were allowed. Digital insertion was used for the first attempt and guided insertion for the second attempt. Oropharyngeal leak pressure and fibreoptic position were determined during cuff inflation from 0 to 40 ml in 10 ml increments. Gastric tube insertion was attempted if there was no gas leak from the drain tube. First attempt and overall insertion success were similar (LMA ProSeal, 92% and 100%; LMA Supreme 95% and 100%). Guided insertion was always successful following failed digital insertion. Oropharyngeal leak pressure was 4-8 ml higher for the LMA ProSeal over the inflation range (p < 0.001). Intracuff pressure was 16-35 cm higher for the LMA ProSeal when the cuff volume was 20-40 ml (p < 0.001). There was an increase in oropharyngeal leak pressure with increasing cuff volume from 10 to 30 ml for both devices, but no change from 0 to 10 ml and 30-40 ml. There were no differences in the fibreoptic position of the airway or drain tube. The first attempt and overall insertion success for the gastric tube was similar (LMA ProSeal 91% and 100%; LMA Supreme 92% and 100%). We conclude that ease of insertion, gastric tube placement and fibreoptic position are similar for the LMA ProSeal and LMA Supreme in paralysed, anaesthetised females, but oropharyngeal leak pressure and intracuff pressure are higher for the LMA ProSeal.

Which airway should I use?

To summarize recent findings for the optimal airway device for patients in the operating room and for medical personnel with limited experience in out-of-hospital airway management. Extraglottic airway devices, like the laryngeal mask airway, are increasingly used for airway management in patients undergoing elective surgery. New devices with separate gastric access reduce the risk of aspiration, providing higher airway seal pressure and extending the range of clinical use (e.g., for patients with surgical procedures in the prone position). The major advantages are reduced airway morbidity and less significant cardiovascular responses. Extraglottic airway devices insertion is easier to learn, and the skill is better retained. Failure to secure the airway in critically ill emergency patients can drastically increase the likelihood of poor or fatal outcome. Recently published studies recommend a shift in the curriculum for medical students and other healthcare providers from conventional laryngoscopic tracheal intubation towards the use of extraglottic airway devices. The intubating laryngeal mask might play a major role because it facilitates both ventilation and tracheal intubation. Extraglottic airway devices are increasingly used for airway management not only in patients for elective surgery, but also in out-of-hospital settings, when less experienced personnel have to secure the airway.

Comparison of Three Disposable Extraglottic Airway Devices in Spontaneously Breathing Adults

Comparison of Three Disposable Extraglottic Airway Devices in Spontaneously Breathing Adults

The anatomical position of three extraglottic airway devices in patients with clear airways

We tested the hypothesis that, in patients with clear airways, the anatomical position of three single-use extraglottic airway devices is similar. The airways studied were: the laryngeal mask airway unique (LMA-U), the Softseal laryngeal mask airway (SS-LM) and the Cobra perilaryngeal airway (Cobra-PLA). Three hundred spontaneously breathing patients were randomly allocated to have their airway managed using one of these three supraglottic airway devices. A rigid endoscope was passed down the airway tube and the following anatomical assessments were made: position of the epiglottis; position of the glottis; and position of the cuff. The epiglottis was more frequently visible with the LMA-U than with the SS-LM (76 vs 57%, p = 0.006) and with the LMA-U than with the Cobra-PLA (76 vs 46%, p < 0.0001). The epiglottis was in contact with the mask aperture bars in 25% of patients, and in 34% of these, the epiglottis was seen to be herniated through the aperture bars. Herniation of the epiglottis through the mask aperture bars occurred more frequently with the Cobra-PLA than the LMA-U (8 vs 3%, p = 0.008). The vocal cords and arytenoids were more frequently visible with the LMA-U and SS-LM than with the Cobra-PLA (both p < 0.006). Herniation of the arytenoids through the mask aperture bars was more frequently seen with the Cobra-PLA than with the LMA-U (8 vs 0%, p = 0.004). The position of the cuff was optimal for the LMA-U and SS-LM in 90% and 93% of patients, respectively. The cuff was more frequently in the midline with the LMA-U than with the SS-LM (p = 0.002). We conclude that the anatomical position of the LMA-U and SS-LMA is superior to that of the Cobra-PLA in patients with clear airways. The mask aperture bars probably have no anatomical utility and predispose to herniation of the pharyngeal structures.

Comparison of Three Disposable Extraglottic Airway Devices in Spontaneously Breathing Adults

The authors compared three disposable extraglottic airway devices in spontaneously breathing anesthetized adults: the LMA-Unique (LMA-U; The Laryngeal Mask Company, San Diego, CA), the Soft Seal laryngeal mask (SS-LM; Portex Ltd., Hythe, United Kingdom), and the Cobra perilaryngeal airway (Cobra-PLA; Engineered Medical Systems, Inc. Indianapolis, IN). Three hundred twenty consecutive adults (American Society of Anesthesiologists physical status I-III; aged 18-80 yr) were randomly allocated for airway management with one of the three devices. Anesthesia was with fentanyl-propofol for induction and a sevoflurane-nitrous oxide-oxygen-fentanyl mixture for maintenance. Intraoperative data were collected by an unblinded observer about ease of insertion, effective airway time, oropharyngeal leak pressure, anatomical position (determined with a rigid endoscope), intracuff pressure changes, and airway trauma. Data were collected by a blinded observer about sore throat, dysphagia, and dysphonia 2 h after surgery. Insertion was easier with the LMA-U and SS-LM than with the Cobra-PLA (P < 0.02), but the overall failure rates were similar. Effective airway times were similar among groups. Oropharyngeal leak pressure was lower with the LMA-U than with the SS-LM and Cobra-PLA (P < 0.001). Intracuff pressure increased during surgery with all extraglottic airway devices. Anatomical position was better with the Cobra-PLA than with the SS-LMA (P < 0.001) and better with the SS-LM than with LMA-U (P < 0.001). Blood staining was detected more frequently with the Cobra-PLA than with the LMA-U and SS-LM (P < 0.001), but there were no differences in airway morbidity. The LMA-U and SS-LM are easier to insert and cause less trauma than the Cobra-PLA, but the Cobra-PLA has a more effective seal than the LMA-U and better endoscopically determined anatomical position than the LMA-U and SS-LM.

Protein cross‐contamination during batch cleaning and autoclaving of the ProSeal™ laryngeal mask airway

We tested the hypothesis that protein cross-contamination occurs during batch cleaning and autoclaving of a reusable extraglottic airway device, the ProSeal laryngeal mask airway. At the end of each day for 10 days, nine laryngeal mask airways that had been used for non-intra-oral surgery were cleaned and autoclaved alongside a new unused laryngeal mask airway. In addition, a new unused laryngeal mask airway underwent the same cleaning and autoclaving procedures in isolation. Protein staining was more frequently detected on the unused laryngeal mask airways that were processed by batch rather than in isolation (p < 0.01). Protein staining was detected on all unused laryngeal mask airways that were processed by batch, but none on those processed in isolation. Protein staining was more severe with the used compared with the unused laryngeal mask airways (p < 0.001). We conclude that protein cross-contamination of the laryngeal mask airway occurs during batch cleaning and autoclaving and recommend that reusable airway devices are cleaned in isolation.

Valve Leaks with New Disposable Extraglottic Airway Devices

Valve Leaks with New Disposable Extraglottic Airway Devices

Rigid Endoscopy for Assessment of Extraglottic Airway Device Position

An established technique for assessing the anatomical position of the laryngeal mask airway is to pass a fiberoptic scope to the distal end of the airway tube.1An alternative technique, which has become routine practice at one of our institutes, is to use a rigid endoscope that is usually used for laparoscopic surgery. The technique involves disconnecting the extraglottic device from the anesthesia breathing system, adopting the sniffing position to align the glottis and mouth, and advancing a 30° rigid endoscope (Hopkins II Forward-Oblique Telescope; Karl Storz, Tuttlingen, Germany) to the distal end of the airway tube. The high resolution images are then viewed on an external monitor. The rigid endoscope uses a rod-lens optical system (invented in 1959 by Harold H. Hopkins, Ph.D. [1918–1994; Professor in Physics, University Reading, Reading, United Kingdom]) and fiberoptic light transmission (invented in 1960 by Karl Storz, M.D. [1911–1996; Founder Karl Storz GmbH &amp; Co., Tuttlingen, Germany]).2A 6.5-mm-OD rigid endoscope is suitable for adults, and a 3-mm-OD rigid endoscope is suitable for children. The 30° angle allows a greater field of view by simply rotating the scope around its longitudinal axis. It is useful to apply an antifog solution (Aesculap; B. Braun, Tuttlingen, Germany) before insertion, but lubrication is rarely needed. We have used this technique in 600 patients using laryngeal mask and other extraglottic airway devices. In most situations, it was used to evaluate the anatomical position, but in some, it was used to diagnose glottic pathology. The technique has only failed on six occasions, and all of these were related to limited mouth opening preventing full insertion of the endoscope along the airway tube. A potential advantage is the high resolution images (fig. 1). Potential disadvantages are the risk of dental trauma and displacement of the extraglottic device; however, to date, these problems have not occurred. Finally, the technique is unsuitable for extraglottic devices with rigid or narrow airway tubes, such as the intubating or ProSeal ™ (Laryngeal Mask Company, Ltd., Nicosia, Cyprus) laryngeal mask airways, respectively.*Catharina Hospital–Brabant Medical School, Eindhoven, The Netherlands. zundert@iae.nl

Valve Leaks with New Disposable Extraglottic Airway Devices

We would like to report six cases of spontaneous cuff deflation that occurred during a clinical trial of a new disposable extraglottic airway device, the CobraPLA® (Engineered Medical Systems, Inc., Indianapolis, IN).1The cuff pressure decreased to almost zero during maintenance of anesthesia. These events were detected by continuous cuff pressure monitoring using a transducer attached to a monitor (S/5 AM; Datex-Ohmeda, Helsinki, Finland) during the maintenance phase of anesthesia and did not influence the clinical performance of the device, primarily because the patients were breathing spontaneously. The patients were not moved during surgery, with the transducer positioned on the patient's shoulder throughout the duration of the procedure. The devices' cuffs were checked for leaks before use as recommended by the manufacturers. When checked after removal of the device, the cuff itself did not show any defect, but submersion in water revealed tiny bubbles of air escaping from the pilot balloon valve, showing a continuous leak at the cuff deflator valves with their surroundings (fig. 1).A similar problem has been reported with another new extraglottic airway mask, the Marshall Laryngeal Airway Device (Marshall Products Ltd., Bath, United Kingdom). In the United Kingdom, the Medical Devices Regulatory Agency issued a Medical Device Alert †in 2003 regarding cuff failure due to a small number of pilot balloon valves leaking. This led to the manufacturer's recall of the product.Cuff deflation is undesirable because it can lead to a loss of seal with the respiratory/gastrointestinal tracts and put the patient at risk of ventilatory failure, aspiration, and gastric insufflation.2We urge the manufacturers of new extraglottic devices to ensure better quality control of their products, including the cuff deflator valves. However, because one cannot guarantee 100% quality control at all times, we also urge clinicians to incorporate cuff pressure monitoring into their routine practice.* Catharina Hospital-Brabant Medical School, Eindhoven, The Netherlands. zundert@iae.nl

CobraPLA™ Is the Perilaryngeal Airway

James Cook University, Cairns Base Hospital, Cairns, Australia. jbrimaco@bigpond.net.auI would like to thank Dr. Alfrey for his positive feedback about my proposed classification system1and for correctly pointing out that the PLA in CobraPLA ™(Engineered Medical Systems, Indianapolis, IN) stands for perilaryngeal airway rather than pharyngeal lumen airway . Dr. Alfrey states that the rationale behind the term perilaryngeal is that the CobraPLA™ head abuts against the aryepiglottic folds near the laryngeal inlet. Perhaps periaryepiglottic would have been a more accurate term, making it the CobraPAA. Interestingly, the use of the prefix peri - in this instance is used to mean “near” rather than “around,” because the CobraPLA™ does not form a seal around the larynx, unlike the Laryngeal Mask Airway® (Laryngeal Mask Company Limited, San Diego, CA).Finally, to the list of modern extraglottic airway devices given in my original proposal1must be added several new products: the Elisha airway device (Elisha Medical Technologies, Katzrin, Israel); disposable versions of the flexible and intubating laryngeal mask airway (Laryngeal Mask Company, San Diego, CA); several disposable laryngeal mask airway–like devices; a modified esophageal tracheal Combitube (Kendall Sheridan Catheter Corporation, Argyle, NY); and the C-Trach® (Laryngeal Mask Company, San Diego, CA), an intubating laryngeal mask airway with built-in fiberoptics and a viewing screen. Many new extraglottic airway devices will make their debuts in the near future; few will stand the test of time. There is no doubt that none will have a name quite as troublesome as the CobraPLA™, at least for those among us with snake phobias.James Cook University, Cairns Base Hospital, Cairns, Australia. jbrimaco@bigpond.net.au

A Modified Rapid Sequence Induction Using the ProSeal™ Laryngeal Mask Airway and an Eschmann Tracheal Tube Introducer or Gum Elastic Bougie

A Modified Rapid Sequence Induction Using the ProSeal™ Laryngeal Mask Airway and an Eschmann Tracheal Tube Introducer or Gum Elastic Bougie

Bleeding, Dysphagia, Dysphonia, Dysarthria, Severe Sore Throat, and Possible Recurrent Laryngeal, Hypoglossal, and Lingual Nerve Injury Associated with Routine Laryngeal Mask Airway Management: Where Is the Vigilance?

Bleeding, Dysphagia, Dysphonia, Dysarthria, Severe Sore Throat, and Possible Recurrent Laryngeal, Hypoglossal, and Lingual Nerve Injury Associated with Routine Laryngeal Mask Airway Management: Where Is the Vigilance?

Is It Unethical to Use the Combitube in Elective Surgery Patients?

Is It Unethical to Use the Combitube in Elective Surgery Patients?