Larynxmaske LMA Supreme™

Assessment of Neck Characteristics for Laryngeal Mask Airway Size Selection in Patients Who Underwent an Elective Ocular Surgery; A Cross-Sectional Study

Objective:

To investigate the neck features for laryngeal mask airway (LMA) size selection.

Methods:

This cross-sectional study was conducted on 160 patients referred for elective surgeries to Feiz Hospital affiliated with Isfahan University of Medical Sciences, Isfahan, Iran (April 2016 to September 2018). Patients underwent ventilation using LMA whose size was determined through a weighted-based approach. All of the patients’ neck characteristics including circumference, thyromental distance, and opening mouth were measured. Ventilation factors were recorded including numbers of attempts for successful LMA insertion, quality of ventilation, and sealing.

Results:

Neck circumference and thyromental distance were significantly different with the size of LMA (p<0.0001 and p=0.005, respectively), but not mouth opening (p=0.21). Neck circumference, thyromental distance, and mouth opening were not significantly different with the times of insertion attempts (p>0.05 for all comparisons). However, the thyromental distance was significantly different with the quality ventilation status (p<0.0001). The total assessment of insertion attempts, ventilation efficacy and sealing was significantly different with the neck circumference (p<0.001), but thyromental distance did not show a significant difference (p>0.05).

Conclusion:

Findings demonstrated that neck circumference might be considered as an appropriate indicator for the selection of LMA size but neither the thyromental distance nor mouth opening. Further studies with a larger sample size are strongly recommended.

Incidence of postoperative sore throat after using a new technique of insertion of a second generation Laryngeal Mask Airway: A randomised controlled trial

BACKGROUND

Sore throat is a common complication after Laryngeal Mask Airway Supreme (SLMA) insertion.

OBJECTIVE

The aim of this study was to determine whether a new SLMA insertion technique (not removing the pilot tube blocker before insertion) lowers the incidence of sore throat in the postanaesthesia care unit (PACU).

DESIGN

A prospective, single-centre, parallel randomised controlled trial.

SETTING

Operating room and PACU at a hospital in China from June to September 2019.

PATIENTS

Four hundred and eight patients aged 18 to 65 years with American Society of Anaesthesiologists physical status class I or II who were scheduled for elective surgery requiring anaesthesia and SLMA insertion.

INTERVENTIONS

Leaving the blocker at the end of the pilot tube in situ (this blocker keeps the valve open and the balloon remains partially inflated but will deflate with pressure) or removing the blocker and actively deflating the cuff before SLMA insertion.

MAIN OUTCOME MEASURES

The primary outcome was the incidence of postoperative sore throat in the PACU. The secondary outcomes included sore throat severity (Prince Henry Hospital Pain Score), first-attempt success rate, ease of insertion, time to successful SLMA insertion, oropharyngeal leak pressure, grade of view on fibreoptic bronchoscopy (indicating the accuracy of SLMA positioning) and adverse events.

RESULTS

The incidence of sore throat was 33/204 (16.2%) in the nonremoval group, and 65/204 (31.9%) in the removal group (P < 0.001). The first-attempt success rate was 174/204 (85.3%) in the nonremoval group and 150/204 (73.76%) in the removal group (P = 0.003; relative risk 1.160, 95% CI 1.049 to 1.282). The Kaplan--Meier curves showed that the insertion time in the nonremoval group was shorter (log-rank P = 0.01).

CONCLUSION

The new insertion technique, leaving the blocker attached to the end of the pilot balloon, resulted in a reduced incidence and severity of postoperative sore throat in the PACU, and an improved first-attempt success rate and the accuracy of SLMA positioning.

TRIAL REGISTRATION

Chinese Clinical Trial Registry identifier: ChiCTR1900023022.

Layperson mouth-to-mask ventilation using a modified I-gel laryngeal mask after brief onsite instruction: a manikin-based feasibility trial

OBJECTIVE

The intention of this manikin-based trial was to evaluate whether laypersons are able to operate an I-gel laryngeal mask (I-gel) modified for mouth-to-mask ventilation after receiving brief on-site instruction.

SETTING

Entrance hall of a university hospital and the city campus of a public technical university, using a protected manikin scenario.

METHODS

Laypersons were handed a labelled, mouthpiece-integrated I-gel laryngeal mask and a corresponding instruction chart and were asked to follow the printed instructions.

OUTCOME MEASURES

The overall process was analysed and evaluated according to quality and duration.

RESULTS

Data from 100 participants were analysed. Overall, 79% of participants were able to effectively ventilate the manikin, 90% placed the laryngeal mask with the correct turn and direction, 19% did not position the mask deep enough and 85% believed that their inhibition threshold for performing resuscitation was lowered. A significant reduction in reluctance before and after the trial was found (p<0.0001). A total of 35% of participants had concerns about applying first aid in an emergency. Former basic life support (BLS) training significantly reduced the time of insertion (19.6 s, 95% CI 17.8 to 21.5, p=0.0004) and increased overall success (p=0.0096).

CONCLUSIONS

Laypersons were able to manage mouth-to-mask ventilation in the manikin with a reasonable success rate after receiving brief chart-based on-site instructions using a labelled I-gel mask. Positioning the mask deep enough and identifying whether the manikin was successfully ventilated were the main problems observed. A significant reduction in reluctance towards initialising BLS by using a modified supraglottic airway device (SAD) may lead to better acceptance of bystander resuscitation in laypersons, supporting the introduction of SADs into BLS courses and the stocking of SADs in units with public automatic external defibrillators.

An Evaluation of Thyromental Distance-based Method or Weight-based Method in Determining the Size of the Laryngeal Mask Airway Supreme: A Randomized Controlled Study

The successful placement of Laryngeal Mask Airway (LMA) Supreme in adults largely depends on right selection of its size. Most anesthesiologists determine the size of LMA according to patients' body weight, which does not always work well. An alternative method should be established to guarantee higher efficacy of ventilation through LMA Supreme placement. This controlled study was designed to compare the efficacy of LMA Supreme placement, when the size of it is determined by body weight or by thyromental distance. Eighty healthy individuals with American Society of Anesthesiologists physical status 1 to 2 scheduled for elective ambulatory surgery were randomly allocated into 2 groups: thyromental distance-based group (n = 40) and weight-based group (n = 40). Efficacy of controlled ventilation through LMA, easy of device placement, and pharyngeal sealing were evaluated between the groups. The tidal volume under 10 cm H2O pressure-controlled ventilation in thyromental distance-based group was significantly higher than that in weight-based group (523.9 ± 135.4 vs 477.1 ± 185.6; P = 0.031). The number of patients who achieved "excellent" tidal volume (>8 mL/kg) were significantly more in the thyromental distance-based group (24/40 vs 13/40; P = 0.019). Among overweight patients (body mass index >23), those who achieved "excellent" tidal volume (>8 mL/kg) under 10 cm H2O pressure-controlled ventilation were also more in thyromental distanced-based group than in weight-based group (11/24 vs 2/24; P = 0.031). The time taken for successful insertion was shorter with the thyromental distance-based group compared with the weight-based group (54.6 ± 33.6 vs 87.8 ± 98.9; P = 0.021). Oropharyngeal leak pressure was pretty close between the 2 groups (26.4 ± 5.1 vs 25.0 ± 5.7 cm H2O; P = 0.180). In terms of guaranteeing better positive pressure ventilation, facilitating device placement, and reliable pharyngeal sealing, thyromental distance-based method can be a better option compared with the weight-based method for LMA Supreme size selection.

Comparison of Laryngeal Mask Airway Supreme(TM) Versus Unique(TM) in Edentulous Geriatric Patients

OBJECTIVE

It is more difficult to perform bag-mask ventilation in edentulous patients than in patients with intact dentition. The laryngeal mask airway (LMA) provides a better alternative to the standard face mask if the facial contours of the patient are not suited for the standard face mask. We aimed to compare these two different LMAs in edentulous geriatric patients.

METHODS

Edentulous patients aged ≥65 years of American Society of Anesthesiologists physical status I-III were included in the study. They were randomly assigned to Supreme group (n=30) and Unique group (n=30). Success of first insertion attempt, ease and time of insertion and oropharyngeal leak pressure were recorded.

RESULTS

The success rate of the first insertion attempt was higher in the Supreme group than in the Unique group (86.6 and 73.3%, respectively; p=0.04). Time of insertion was similar (10.04 s and 11.87 s, respectively) and insertion was easy in 90% and 100% of patients, respectively. Oropharyngeal leak pressures were measured as 20.56-cm H2O and 17.10-cm H2O for LMA Supreme™ and LMA Unique™, respectively.

CONCLUSION

The efficacy and safety in both groups were comparable in edentulous geriatric patients during short surgical procedures. Even the success rate of insertion with both was lower than that mentioned in the literature; the success of insertion at the first attempt was superior with the LMA Supreme™ in our edentulous study group.

Comparison of the Supraglottic Airway Devices Classic, Fastrach and Supreme Laryngeal Mask Airway: A Prospective Randomised Clinical Trial of Efficacy, Safety and Complications

OBJECTIVE

This prospective randomised study was designed to compare the Laryngeal Mask Airway (LMA) Classic, LMA Fastrach and LMA Supreme regarding ease of insertion and insertion time as primary outcomes and reposition, success rate of trials, effects on haemodynamic parameters, provision of an adequate and safe airway, amount of leakage and oropharyngeal and systemic complications as secondary outcomes.

METHODS

In this clinical trial, 90 patients aged 18-70 years of American Society of Anesthesiologists (ASA) group I-II were randomised into three groups as providing airway via LMA Classic, LMA Fastrach or LMA Supreme instead of tracheal intubation. No muscle relaxant was used. The allocated LMA was inserted by the same anaesthetist; bispectral index (BIS) was between 40% and 60%.

RESULTS

There was no statistical difference among the groups regarding the ease of insertion and insertion time as primary outcomes; the incidence of repositioning during placement was significantly higher in the LMA Classic group than that in other groups (p<0.05) and the rates of bloodstain on the device as well as oropharyngeal mucosal oedema were higher in the LMA Fastrach group than those in other groups (p<0.05) as secondary outcomes.

CONCLUSION

We suggest that LMA Classic, LMA Supreme and LMA Fastrach had similar effectiveness regarding efficiency and airway safety. However, LMA Supreme seems to be more advantageous as it is more appropriate for fewer oropharyngeal complications and there was no repositioning.

Basic life support trained nurses ventilate more efficiently with laryngeal mask supreme than with facemask or laryngeal tube suction-disposable--a prospective, randomized clinical trial

OBJECTIVE

In some emergency situations resuscitation and ventilation may have to be performed by basic life support trained personnel, especially in rural areas where arrival of advanced life support teams can be delayed. The use of advanced airway devices such as endotracheal intubation has been deemphasized for basically-trained personnel, but it is unclear whether supraglottic airway devices are advisable over traditional mask-ventilation.

METHODS

In this prospective, randomized clinical single-centre trial we compared airway management and ventilation performed by nurses using facemask, laryngeal mask Supreme (LMA-S) and laryngeal tube suction-disposable (LTS-D). Basic life support trained nurses (n=20) received one-hour practical training with each device. ASA 1-2 patients scheduled for elective surgery were included (n=150). After induction of anaesthesia and neuromuscular block nurses had two 90-second attempts to manage the airway and ventilate the patient with volume-controlled ventilation.

RESULTS

Ventilation failed in 34% of patients with facemask, 2% with LMA-S and 22% with LTS-D (P<0.001). In patients who could be ventilated successfully mean tidal volume was 240±210 ml with facemask, 470±120 ml with LMA-S and 470±140 ml with LTS-D (P<0.001). Leak pressure was lower with LMA-S (23.3±10.8 cm H2O, 95% CI 20.2-26.4) than with LTS-D (28.9±13.9 cm·H2O, 95% CI 24.4-33.4; P=0.047).

CONCLUSIONS

After one hour of introductory training, nurses were able to use LMA-S more effectively than facemask and LTS-D. High ventilation failure rates with facemask and LTS-D may indicate that additional training is required to perform airway management adequately with these devices. High-level trials are needed to confirm these results in cardiac arrest patients.

Transfer of airway skills from manikin training to patient: success of ventilation with facemask or LMA-Supreme(TM) by medical students

During emergency care, the ability to ventilate the patient's lungs is a crucial skill. Supraglottic airway devices have an established role in emergency care, and manikin trials have shown that placement is easy even for inexperienced users. However, there is current discussion as to what extent these results can be transferred to patients. We studied the transfer of skills learnt on a manikin to the clinical situation in novice medical students during their anaesthesia rotation. They were required to ventilate the lungs of a manikin using a facemask and then position a supraglottic airway device (LMA-Supreme™) and ventilate the lungs. This process was then repeated on anaesthetised patients, with standard ventilator settings to assess adequacy of ventilation. Sixty-three students participated in the manikin study. The success rate for ventilating the lungs was 100% for both devices, but the mean (SD) time to achieve successful ventilation was 27.8 (24.4) s with the facemask compared with 38.6 (22.0) s with the LMA-Supreme (p = 0.008). Fifty-one of the students progressed to the second part of the study. In anaesthetised patients, the success rate for ventilating the lungs was lower for the facemask, 27/41 (66%) compared with the LMA-Supreme 37/41 (90%, p = 0.006). For 26 students who succeeded with both devices, the tidal volume was lower using the facemask, 431 (192) ml compared with the LMA-Supreme 751 (221) ml (p = 0.001), but the time to successful ventilation did not differ, 60.0 (26.2) s vs 57.3 (26.6) s (p = 0.71). We conclude that the results obtained in manikin studies cannot be transferred directly to the clinical situation and that guidelines should take this into account. Based on our findings, a supraglottic airway device may be preferable to a facemask as the first choice for inexperienced emergency caregivers.

The effect of a cervical collar on the seal pressure of the LMA Supreme™: a prospective, crossover trial

For personnel inexperienced in airway management, supraglottic airway devices may be the first choice in an emergency. Changing head position is known to reduce the seal pressure of a laryngeal mask airway. The aim of this study was to investigate whether the use of a cervical collar improves the stability of airways secured with the LMA Supreme™ (The Laryngeal Mask Company Limited, Mahé, Seychelles). In this crossover trial, the primary endpoint was the difference in the seal pressure of the LMA Supreme in anaesthetised patients in maximum passive extension of the neck, with and without a cervical collar. The median (IQR [range]) seal pressure was 18 (13.8-22.1 [0-30]) cmH(2) O in maximum passive extension without a cervical collar. With a cervical collar in place, the seal pressure increased to 28 (22.8-30 [17-30]) cmH(2) O (p<0.001). In the neutral head position, the seal pressure was 22 (17.6-24.5 [12-30]) cmH(2) O without and 27 (22-30 [12-30]) cmH(2) O with a cervical collar in place (p<0.001). We found that a cervical collar stabilises the airway with an LMA Supreme in place and we recommend this combination for (pre-hospital) emergency cases.

[Measurement of carbon dioxide in emergency medicine]

Expiratory carbon dioxide (CO(2)) monitoring is a valuable tool in the prehospital setting. Recent reports of misplaced endotracheal tubes in the prehospital setting make it important to ensure that tube placement is verified by CO(2) monitoring. The Euronorm 2007:1789 made provision of capnometry mandatory for all medical vehicles. However, the frequency of utilization of CO(2) monitoring after securing the airway and in patients with respiratory insufficiency is low. This article covers the terminology, physiology, technology and clinical applications of CO(2) monitoring. Monitoring of cardiac output and the efficiency of cardiopulmonary resuscitation are described and the article also highlights the importance of CO(2) monitoring in patients with severe head trauma as well as restrictive and obstructive pulmonary disorders.

Does a 4 diagram manual enable laypersons to operate the Laryngeal Mask Supreme®? A pilot study in the manikin

Background

Bystander resuscitation plays an important role in lifesaving cardiopulmonary resuscitation (CPR). A significant reduction in the "no-flow-time", quantitatively better chest compressions and an improved quality of ventilation can be demonstrated during CPR using supraglottic airway devices (SADs). Previous studies have demonstrated the ability of inexperienced persons to operate SADs after brief instruction. The aim of this pilot study was to determine whether an instruction manual consisting of four diagrams enables laypersons to operate a Laryngeal Mask Supreme^® (LMAS) in the manikin.

Methods

An instruction manual of four illustrations with speech bubbles displaying the correct use of the LMAS was designed. Laypersons were handed a bag containing a LMAS, a bag mask valve device (BMV), a syringe prefilled with air and the instruction sheet, and were asked to perform and ventilate the manikin as displayed. Time to ventilation was recorded and degree of success evaluated.

Results

A total of 150 laypersons took part. Overall 145 participants (96.7%) inserted the LMAS in the manikin in the right direction. The device was inserted inverted or twisted in 13 (8.7%) attempts. Eight (5.3%) individuals recognized this and corrected the position. Within the first 2 minutes 119 (79.3%) applicants were able to insert the LMAS and provide tidal volumes greater than 150 ml (estimated dead space). Time to insertion and first ventilation was 83.2 ± 29 s. No significant difference related to previous BLS training (P = 0.85), technical education (P = 0.07) or gender could be demonstrated (P = 0.25).

Conclusion

In manikin laypersons could insert LMAS in the correct direction after onsite instruction by a simple manual with a high success rate. This indicates some basic procedural understanding and intellectual transfer in principle. Operating errors (n = 91) were frequently not recognized and corrected (n = 77). Improvements in labeling and the quality of instructional photographs may reduce individual error and may optimize understanding.

Laypersons can successfully place supraglottic airways with 3 minutes of training. A comparison of four different devices in the manikin

INTRODUCTION

Supraglottic airway devices have frequently been shown to facilitate airway management and are implemented in the ILCOR resuscitation algorithm. Limited data exists concerning laypersons without any medical or paramedical background. We hypothesized that even laymen would be able to operate supraglottic airway devices after a brief training session.

METHODS

Four different supraglottic airway devices: Laryngeal Mask Classic (LMA), Laryngeal Tube (LT), Intubating Laryngeal Mask (FT) and CobraPLA (Cobra) were tested in 141 volunteers recruited in a technical university cafeteria and in a shopping mall. All volunteers received a brief standardized training session. Primary endpoint was the time required to definitive insertion. In a short questionnaire applicants were asked to assess the devices and to answer some general questions about BLS.

RESULTS

The longest time to insertion was observed for Cobra (31.9 ± 27.9 s, range: 9-120, p < 0.0001; all means ± standard deviation). There was no significant difference between the insertion times of the other three devices. Fewest insertion attempts were needed for the FT (1.07 ± 0.26), followed by the LMA (1.23 ± 0.52, p > 0.05), the LT (1.36 ± 0.61, p < 0.05) and the Cobra (1.45 ± 0.7, p < 0.0001). Ventilation was achieved on the first attempt significantly more often with the FT (p < 0.001) compared to the other devices. Nearly 90% of the participants were in favor of implementing supraglottic airway devices in first aid algorithms and classes.

CONCLUSION

Laypersons are able to operate supraglottic airway devices in manikin with minimal instruction. Ventilation was achieved with all devices tested after a reasonable time and with a high success rate of > 95%. The use of supraglottic airway devices in first aid and BLS algorithms should be considered.

Performance of supraglottic airway devices and 12 month skill retention: a randomized controlled study with manikins

PURPOSE

Airway management for successful ventilation by laypersons and inexperienced healthcare providers is difficult to achieve. Bag-valve mask (BVM) ventilation requires extensive training and is performed poorly. Supraglottic airway devices (SADs) have been successfully introduced to clinical resuscitation practice as an alternative. We evaluated recently introduced (i-gel™ and LMA-Supreme™) and established SADs (LMA-Unique™, LMA-ProSeal™) and BVM used by laypeople in training sessions on manikins.

METHODS

In this randomized controlled study, 267 third-year medical students participated with informed consent and IRB approval. After brief standardized training, each participant applied all devices in a randomized order. Success of device application and ventilation was recorded. Without further training, skill retention was assessed in the same manner 12 months later. Outcome parameters were the number of application attempts, application time, tidal volume and gastric inflation rate recorded at successful attempts, and subjective ease-of-use rating by the participants.

RESULTS

i-gel™ and LMA-Supreme™ were the most successful in the first attempt at both assessments and in the subjective ease-of-use rating. The shortest application time was found with BVM (8 ± 5s in 2008 vs. 9 ± 5s in 2009) and i-gel (10 ± 3s vs. 12 ± 5s). Tidal volumes were disappointing with no device reaching 50% volume within the recommended range (0.4-0.6L). Gastric inflation rate was highest with BVM (18% vs. 20%) but significantly lower with all SADs (0.4-6%; p < 0.001 for 2008 and 2009).

CONCLUSION

SADs showed clear advantages over BVM. Compared with LMA-Unique™ and LMA-ProSeal™, i-gel™ and LMA-Supreme™ led to higher first-attempt success rates and a shorter application time.

The intuitive use of laryngeal airway tools by first year medical students

Background

Providing a secured airway is of paramount importance in cardiopulmonary resuscitation. Although intubating the trachea is yet seen as gold standard, this technique is still reserved to experienced healthcare professionals. Compared to bag-valve facemask ventilation, however, the insertion of a laryngeal mask airway offers the opportunity to ventilate the patient effectively and can also be placed easily by lay responders. Obviously, it might be inserted without detailed background knowledge.

The purpose of the study was to investigate the intuitive use of airway devices by first-year medical students as well as the effect of a simple, but well-directed training programme. Retention of skills was re-evaluated six months thereafter.

Methods

The insertion of a LMA-Classic and a LMA-Fastrach performed by inexperienced medical students was compared in an airway model. The improvement on their performance after a training programme of overall two hours was examined afterwards.

Results

Prior to any instruction, mean time to correct placement was 55.5 ± 29.6 s for the LMA-Classic and 38.1 ± 24.9 s for the LMA-Fastrach. Following training, time to correct placement decreased significantly with 22.9 ± 13.5 s for the LMA-Classic and 22.9 ± 19.0 s for the LMA-Fastrach, respectively (p < 0.05). After six months, the results are comparable prior (55.6 ± 29.9 vs 43.1 ± 34.7 s) and after a further training period (23.5 ± 13.2 vs 26.6 ± 21.6, p < 0.05).

Conclusion

Untrained laypersons are able to use different airway devices in a manikin and may therefore provide a secured airway even without having any detailed background knowledge about the tool. Minimal theoretical instruction and practical skill training can improve their performance significantly. However, refreshment of knowledge seems justified after six months.