LMA ClassicTM Research Articles

Comparison of the insertion of LMA classicTM by the standard insertion technique Vs the 90-degree rotational technique - A prospective randomised comparative study

Comparison of the insertion of LMA classicTM by the standard insertion technique Vs the 90-degree rotational technique - A prospective randomised comparative study

English

English

Prolonged Use of the Laryngeal Mask Airway ProSealTM: A Report of Seven Cases Lasting 5-11 h

Background: There is controversy concerning use of laryngeal mask airway devices for procedures lasting more than 2 h. The LMA ProSealTM is a laryngeal mask device with a modified cuff to facilitate ventilation and a drain tube to provide airway protection that is better suited for prolonged use than the LMA ClassicTM. Objectives: We aimed to describe the successful use of the LMA ProSealTM in seven patients in a variety of clinical situations for procedures lasting more than 5 h and provide practical guidelines about its use in this situation. Results: The cases illustrate the use of the LMA ProSealTM in a variety of clinical situations (supine and prone position) and for a variety of prolonged procedures: as a planned airway device and as an airway rescue device. LMA ProSealTM forms an effective seal with the respiratory tract (10 cm H2O higher) and is therefore suited as ventilator device. It also forms an effective seal with the gastrointestinal tract (30 cm H2O higher), provides protection against aspiration and gastric insufflation and provides easy access to the gastrointestinal tract allowing the passage of a gastric tube reducing again the risk of aspiration. Conclusion: The use of the LMA ProSealTM for prolonged procedures is feasible. In principle, it should be safer and more effective than the LMA ClassicTM.

Comparison of three supraglottic airway devices for airway rescue in the prone position: A manikin-based study.

Background:Accidental extubation during surgery in prone position can be life-threatening. Supraglottic airway devices (SAD) have been used successfully in such situations to rescue the airway. However, which SAD would be most appropriate in this setting has not been described in the literature.Aims:The aim of our study was to determine the most appropriate SAD for securing airway in a prone position during accidental extubation.Materials and Methods:In the study, Airway Trainer (Laerdal) manikin was used for studying insertion of three SADs; I-gel, Laryngeal Mask Airway ProSeal™ (PLMA) and LMA Classic™ (CLMA) in the prone position. Forty anesthesia resident doctors participated in this study. The time taken for insertion; ease of insertion and ventilation; bronchoscopic view; and insertion score were compared among the three groups.Results:The time taken for I-gel insertion was significantly lesser (12.89 ± 3.94 seconds) as compared to CLMA (17.07 ± 3.5 seconds) and PLMA (25 + 4.78 seconds). Least resistance was encountered in the insertion of I-gel, while maximum resistance was experienced in PLMA group (22.5% vs. 90%). The maneuver required for optimal positioning was observed in 27.5% of PLMA insertion, 2.5% in CLMA while no maneuver was required in any of the I-gel insertion. Ease of ventilation was comparable in all three SADs. The bronchoscopic view and insertion score were significantly higher with I-gel as compared to CLMA and PLMA.Conclusion:All three SADs were successful as rescue devices during accidental extubation in the prone position. However, the ease of insertion was maximum with I-gel, followed by CLMA and PLMA.

Failure of the Laryngeal Mask Airway Unique™ and Classic™ in the Pediatric Surgical Patient

Background Although predictors of laryngeal mask airway failure in adults have been elucidated, there remains a paucity of data regarding laryngeal mask airway failure in children. Methods The authors performed a retrospective database review of all pediatric patients who received a laryngeal mask anesthetic at their institution from 2006 to 2010. Device brands were restricted to LMA Unique™ (Cardinal Health, Dublin, OH) and LMA Classic™ (LMA North America, San Diego, CA), and primary outcome was laryngeal mask failure, defined as any airway event requiring device removal and tracheal intubation. Potential risk factors were analyzed with both univariate and multivariate techniques and included medical history, physical examination, surgical, and anesthetic characteristics. Results Of the 11,910 anesthesia cases performed in the study, 102 cases (0.86%) experienced laryngeal mask failure. Common presenting features of laryngeal mask failures included leak (25%), obstruction (48%), and patient intolerance such as intractable coughing/bucking (11%). Failures occurred before incision in 57% of cases and after incision in 43%. Independent clinical associations included ear/nose/throat surgical procedure, nonoutpatient admission status, prolonged surgical duration, congenital/acquired airway abnormality, and patient transport. Conclusions The findings of the study support the use of the LMA Unique™ and LMA Classic™ as reliable pediatric supraglottic airway devices, demonstrating relatively low failure rates. Predictors of laryngeal mask airway failure in the pediatric surgical population do not overlap with those in the adult population and should therefore be independently considered.

The LMA Classic™ as a conduit for tracheal intubation in adult patients: a review and practical guide

AbstractUnexpected difficulty in maintaining an open airway following induction of anaesthesia remains an ever-present hazard. Repetitive attempts at direct laryngoscopy and intubation are generally acknowledged to be inappropriate. The LMA ClassicTM is recognised as a rescue ventilation device in failed intubation scenarios and its specific role is well defined in international airway management protocols. Should clinical conditions dictate the need for tracheal intubation following placement of an LMA ClassicTM, it may be retained to serve as a conduit for intubation. Utilising the LMA ClassicTM as a conduit for intubation is considered a rescue manoeuvre, only resorted to when conventional methods such as direct laryngoscopy have failed. Therefore, it is important that this approach to intubation has a high success rate and that airway management specialists are familiar with the different available options, the relevant limitations and the pitfalls. A short description of the components of the LMA Cla...

Failure of the Laryngeal Mask Airway Unique™ and Classic™ in the Pediatric Surgical Patient

Although predictors of laryngeal mask airway failure in adults have been elucidated, there remains a paucity of data regarding laryngeal mask airway failure in children. The authors performed a retrospective database review of all pediatric patients who received a laryngeal mask anesthetic at their institution from 2006 to 2010. Device brands were restricted to LMA Unique™ (Cardinal Health, Dublin, OH) and LMA Classic™ (LMA North America, San Diego, CA), and primary outcome was laryngeal mask failure, defined as any airway event requiring device removal and tracheal intubation. Potential risk factors were analyzed with both univariate and multivariate techniques and included medical history, physical examination, surgical, and anesthetic characteristics. Of the 11,910 anesthesia cases performed in the study, 102 cases (0.86%) experienced laryngeal mask failure. Common presenting features of laryngeal mask failures included leak (25%), obstruction (48%), and patient intolerance such as intractable coughing/bucking (11%). Failures occurred before incision in 57% of cases and after incision in 43%. Independent clinical associations included ear/nose/throat surgical procedure, nonoutpatient admission status, prolonged surgical duration, congenital/acquired airway abnormality, and patient transport. The findings of the study support the use of the LMA Unique™ and LMA Classic™ as reliable pediatric supraglottic airway devices, demonstrating relatively low failure rates. Predictors of laryngeal mask airway failure in the pediatric surgical population do not overlap with those in the adult population and should therefore be independently considered.

New supraglottic airway with built-in pressure indicator decreases postoperative pharyngolaryngeal symptoms: a randomized controlled trial

Excessive supraglottic airway cuff pressure increases postoperative pharyngolaryngeal symptoms such as sore throat, dysphonia, and dysphagia. A new supraglottic airway, AES Ultra CPV™ (CPV), has a built-in intracuff pressure indicator. We hypothesized that using the CPV would reduce postoperative symptoms when compared with the LMA Classic™ (LMA) without intracuff pressure guidance. Ambulatory patients undergoing general anesthesia were randomized to either CPV or LMA. A size 3/4/5 was inserted according to manufacturer guidelines. Nitrous oxide was not used. In the LMA Group, the cuff was inflated according to manufacturer's guidelines. In the CPV Group, a CPV was inserted and the cuff inflated until the indicator was in the green zone (30-44 mmHg). Intracuff pressures were measured at five minutes and 20 min post-insertion in both groups. The primary outcome was the incidence of pharyngolaryngeal symptoms, defined as sore throat, dysphonia, and/or dysphagia at one, two, and/or 24 hr postoperatively. Continuous data were compared using Student's t test and categorical data were analyzed using Chi square analysis. The study included 170 patients, 85 per group. The mean (SD) intracuff pressure in the CPV group was significantly lower [44 (4) mmHg] than in the LMA Group [87 (37) mmHg]; P < 0.001. The incidence of pharyngolaryngeal symptoms was significantly lower in the CPV Group than in the LMA Group (26% vs 49%; P = 0.002). The absolute risk reduction was 24%, and the number-needed-to-treat was 4.3. The incidence of postoperative pharyngolaryngeal symptoms in the CPV Group with a cuff pressure-guided strategy was significantly lower than in the LMA Group with standard practice. ( NCT01800344).

Use of intubation introducers through a supraglottic airway to facilitate tracheal intubation: a brief review

This article is a narrative review regarding the usage and effectiveness of introducers or catheters to facilitate tracheal intubation through a supraglottic airway (SGA) as an alternative intubation technique in normal and difficult airway management. Relevant articles were obtained through Medline (1948-July 2011). The articles were subsequently cross-referenced for additional literature, and only articles published in English were included. In this review, we consider 32 reports using the LMA Classic™, LMA Unique™, LMA ProSeal™, LMA Supreme™, AuraOnce™, and i-gel™ as SGA conduits for intubation. In 13 articles, the use of an Aintree Intubation Catheter was described as an intubation introducer and resulted in high success rates in both elective and emergent situations. Eight studies used a guidewire exchange catheter technique. Although blind intubation using a guidewire resulted in a high failure rate, these studies found that using a bronchoscope improved successful intubation. Ten studies showed that insertion of a gum elastic bougie with a bronchoscope as an intubation introducer has high success rates compared with blind bougie insertion. One article described the use of a small endotracheal tube as an intermediary for tracheal intubation. In failed intubation scenarios, supraglottic airways, such as the LMA Classic™ or LMA ProSeal™ can serve as a conduit for tracheal intubation. A number of techniques using introducers or catheters can facilitate the insertion of an adequately sized endotracheal tube, particularly guided by a bronchoscope. Usage of introducers or catheters through a supraglottic airway may be a useful alternative intubation technique in difficult airway management.

Längenverhältnis von Trachealtubus zur Larynxmaske

Management of difficult airways and difficult intubation differs in pediatric and in adult patients. In conscious children, fiberoptic intubation is not feasible because of limited compliance. The specially designed laryngeal mask for blind tracheal intubation, LMA Fastrach™, is available for adolescents and adults only. Therefore, fiberoptic-guided intubation through a supraglottic airway device (SAD) is a standard technique for the management of difficult intubation in children. While performing the procedure, stabile positioning of the endotracheal tube (ETT) and prevention of dislodgement are critical issues. The relationship between the length of the ETT and the SAD is highly important and was investigated in this in vitro study.In this study 6 different brands of SAD in the pediatric sizes 1-3 and 2 different ETT brands (cuffed, Microcuff(®), uncuffed, Sheridan PED-SOFT™) were investigated. Using pediatric growth tables, the recommended patient weight for each SAD size was correlated to patient age and then to appropriately sized cuffed and uncuffed ETTs. The ETT size was chosen according to the manufacturer's recommendations (cuffed ETT) and according to the literature (uncuffed ETT). The various SAD-ETT pairs were assessed with regard to differences in their length. After lubrication with silicone the ETT with a firmly attached 15 mm tube adapter was maximally inserted into the SAD and the ETT tip overlapping the SAD cuff was measured. Secondarily, an adapter for fiberoptic procedures was interposed and the measurements repeated.For a defined patient uncuffed ETTs were usually selected with a larger internal diameter (ID) compared to cuffed ETTs. Therefore, the uncuffed ETT is the longer one and will overlap the SAD by a longer tip. Comparing the curved SAD brands AuraOnce™ and Aura-i™, the Aura-i™ devices generally showed shorter tubes resulting in a longer protruding ETT tip (median 1.5 cm, minimum-maximum 1.0-2.4 cm). The straight brands LMA classic™, AuraStraight™ and LMA Unique™ showed similarity in tube length. In comparison with i-gel(®), for the SAD sizes 1-2.5 the former provide a longer projecting ETT tip. Only i-gel(®) together with AuraStraight™ showed the longest overlapping ETT tip for SAD size 3. If a swivel adapter was used during the fiberoptic intubation procedure, the length of the ETT could be critically reduced in relation to the length of the SAD. Using a swivel adapter from VBM Medizintechnik, (Sulz a. N., Germany) a relative reduction in ETT length of 2.3 or 3.2 cm has to be taken into account.For fiberoptic-guided endotracheal intubation through an SAD, sufficient length of the ETT in relation to the SAD is mandatory. Differences in geometry between SAD and ETT brands have to be considered. The selection of a relatively small SAD in combination with an uncuffed ETT might be advantageous. Redesigned extra long ETTs would be desirable to decrease the risk for ETT dislocation and to increase the safety of the technique. Restrictive use of a swivel adapter during the procedure is important because of further and potentially critical decreases in ETT length. In addition, after successful intubation of the trachea, removal of the SAD via an airway exchange catheter and replacement of the cuffed ETT of choice in the correct position is recommended to secure the airway and provide unimpaired ventilation and oxygenation.

A prospective randomized trial comparing supraglottic airways for flexible bronchoscopy in children

A prospective randomized, controlled trial was conducted comparing supraglottic airways (SGA) for flexible bronchoscopy in 100 children. Pediatric flexible bronchoscopy is commonly performed using a SGA as both a ventilation device and a conduit for flexible bronchoscopy. We observed that some disposable SGAs were associated with increased resistance to bronchoscope manipulation compared to the LMA Classic (cLMA). We compared the cLMA to the Ambu Aura Once, Portex Soft Seal, Boss Systems disposable silicone laryngeal mask, and LMA Unique. We recorded the subjective resistance of the bronchoscope manipulation within the SGA by linear analog score and measured the time to insert the bronchoscope from the proximal end of the SGA to the right upper lobe. We also scored the view of the larynx through the bronchoscope and measured SGA cuff pressures. Resistance to bronchoscope manipulation during pediatric flexible bronchoscopy was higher using polyvinyl chloride (PVC) disposable SGAs (Ambu, Unique, and Portex) than the silicone re-usable cLMA (P < 0.0001). The Unique and Ambu laryngeal masks were clinically inferior to the cLMA at all levels of the airway (P < 0.0001). The Portex Soft Seal was not different above the larynx but was significantly statistically inferior at (P < 0.04) and below the larynx (P < 0.006) and inferior overall (P < 0.007). Boss Systems single-use laryngeal mask was as effective as the cLMA. In this trial, PVC single-use laryngeal masks were inferior to the silicone cLMA and Boss Systems laryngeal masks for flexible bronchoscopy in children.

Which laryngeal mask for fiberoptic-aided wire-guided catheter exchange tracheal intubation? The Classic-LMATM or the Proseal-LMATM: a mannequin study

Study Objective: To compare the ease of use, operator preference, time to completion, and failure rates while performing a fiberoptic-aided wire-guided airway exchange tracheal intubation through the the LMA-Classic TM and LMA-Proseal .Design: Prospective, randomized trialSetting: SimulationInterventions: Twenty-five participants of various experience grades performed four intubations each, one hundred intubations total, on an AirSim TM airway trainer through a #3 laryngeal mask using a fiberoptic endoscope and an Arndt Airway Exchange Catheter Set.Measurements: Laryngeal view after LMA insertion was graded by one of the investigators. The time to intubation and any intubation failures were recorded. Participants were asked to rate the ease of performing the intubation through each LMA and which device they preferred.Main Results: Intubation was reported to be easier through the cLMA than the pLMA. Consequently, participants preferred the cLMA for use as an airway conduit. However, the time to completion and failure rates were essentially the same in all groups. First attempt intubation success rate was 92% overall.Conclusion: Fiberoptic-aided wire-guided catheter exchange intubation can be performed successfully through either the cLMA or the pLMA. Personal experience with each device should dictate which device is chosen initially. GRANTS, SPONSORS, AND FUNDING SOURCES The AirSim TM airway trainer used in this study was supported by intramural departmental funds

Randomised crossover comparison of the Ambu® AuraOnceTM Laryngeal Mask with the LMA ClassicTM laryngeal mask airway in paralysed anaesthetised patients*

SummaryWe compared the performance of the Ambu® AuraOnceTM Laryngeal Mask with that of the LMA ClassicTM laryngeal mask airway during controlled anaesthesia. Forty patients requiring intermittent positive pressure ventilation were studied using a randomised crossover design. The mean (SD) oropharyngeal leak pressure for the Ambu device (19 (7.5) cmH2O) was significantly greater than for the LMA Classic (15 (5.2) cmH2O; p = 0.004), and the number of attempts for successful insertions was significantly less (39 (50%) vs 45 (56%), respectively; p = 0.02). There was one failure to obtain a patent airway with the Ambu Laryngeal Mask and none with the LMA Classic. Insertion of the Ambu Laryngeal Mask required more manipulations to achieve a patent airway than did the LMA Classic (6 (15%) vs 1 (2.5%), respectively; p = 0.045), but the time taken for insertion was similar between the two groups. The incidence of trauma, grade of fibreoptic view, peak airway pressure and quality of ventilation during maintenance of anaesthesia were similar in both groups.

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?