A comparison of the intubating and standard laryngeal mask airways for airway management by inexperienced personnel

Ambu AuraGain versus intubating laryngeal tube suction as a conduit for endotracheal intubation

Background and Aims

Newly developed supraglottic airway devices (SGAs) are designed to be used both for ventilation and as conduits for endotracheal intubation with standard endotracheal tubes (ETTs). We compared the efficacy of the Ambu AuraGain (AAG) and the newly developed intubating laryngeal tube suction disposable (ILTS-D) as conduits for blind and fiber-optically guided endotracheal intubation in an airway mannequin.

Material and Methods

This is a prospective, randomized, crossover study in an airway mannequin, with two arms: blind ETT insertion by medical students and fiber-optically guided ETT insertion by anesthesiologists. The primary outcome variable was the time to achieve an effective airway through an ETT using AAG and ILTS-D as conduits. Secondary outcome variables were the time to achieve effective supraglottic ventilation and successful exchange with an ETT, and the success rates for blind endotracheal intubation and fiber-optically guided intubation techniques for both SGAs.

Results

Forty participants were recruited to each group. All participants were able to insert both devices successfully on the first attempt. For blind intubation, the success rate for establishing a definitive airway with an ETT using the SGA as a conduit was significantly higher with ILTS-D (82.5%) compared with AAG (20.0%) (P < 0.001). None of the participants were able to successfully complete the exchange of the SGA for the ETT with the AAG. In the fiber optic guided intubation group, the rate of successful exchange was significantly higher with ILTS-D (84.6%) compared with AAG (61.5%) (P = 0.041).

Conclusion

The ILTS-D successfully performs in an airway mannequin with higher success rate and shorter time for blindly establishing an airway with an ETT using the SGA as a conduit, compared with AAG. Further clinical trials are warranted.

Evaluation of the Intubating Laryngeal Mask Airway™ Used by Occasional Intubators in Simulated Trauma

This observational study assessed the potential role of the intubating laryngeal mask airway (ILMA™ ) for use by emergency care givers with limited laryngoscopy skills.

Six ambulance officers with advanced airway training, five doctors with intubation experience and five doctors without intubation experience were given a short instruction course on the use of the ILMA. They subsequently used the device on 80 consenting subjects anaesthetized for elective surgery after the application of cricoid pressure and manual in-line stabilization of the cervical spine. All patients were successfully ventilated via the ILMA. Mean (SD) times in seconds to ventilation were 27 (10), 33 (18) and 47 (22) respectively in the occasional intubator ambulance officers, occasional intubator doctor and naï ve intubator groups. The numbers (percentage) failures to intubate via the ILMA in each group were 2 (7%), 5 (20%) and 4 (16%) respectively. Mean (SD) times in seconds to intubation were 32 (23), 32 (17) and 36 (25). There was no evidence of “learning” with repeated use. The feedback forms were strongly supportive of a prehospital trial and also of having an ILMA available during all intubations. Participants almost universally rated the ILMA as easy to use. This study supports further evaluation of the ILMA in a large pre-hospital trial.

Evaluation of the SLIPA™ (Streamlined Liner of the Pharynx Airway), a Single Use Supraglottic Airway Device, in 60 Anaesthetized Patients Undergoing Minor Surgical Procedures

The Streamlined Liner of the Pharyngeal Airway, SLIPA™ (Hudson RCI) is a new disposable supraglottic airway device that has no inflatable cuff and has features designed to reduce aspiration risk. This study aimed to assess the insertion success and effectiveness of the SLIPA™ in 60 patients who presented for elective surgery. Ethics committee approval was obtained. Patients were excluded if they were less than 18 years, had not provided written consent or were at risk of pulmonary aspiration. The first 20 SLIPA™ were inserted by the principal investigator (Group A) followed by another 40 inserted by medical officers and anaesthetists of varying experience (Group B). Twenty-one males and 39 females were recruited into the study. Median time to ventilation was 20.4 seconds in Group A (range 12.9-109) and 24.8 seconds in Group B (range 8.2-82.5). Overall success rate was 100% in Group A and 92.5% in Group B. The lowest recorded SpO2 was 91% in Group B. The incidence of blood and sore throat score >3 (0-10 scale) was 23% and 7% respectively (Groups A and B). Group B reported that use of the device was very easy in 16%, easy in 76%, difficult in 5%, and very difficult in 3%. The SLIPA™ proved to be a reliable airway providing adequate ventilation in both spontaneous breathing and assisted respiration. Most users found the SLIPA™ to be easy or very easy to use.

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.

[Extraglottic airway devices in the intensive care unit]

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.

Laryngeal mask airways have a lower risk of airway complications compared with endotracheal intubation: a systematic review

PURPOSE

The purpose of the present study was to determine whether, in patients undergoing general anesthesia, those provided with a laryngeal mask airway (LMA) have a lower risk of airway-related complications than those undergoing endotracheal intubation.

MATERIALS AND METHODS

A systematic review of randomized prospective controlled trials was done to compare the risk of airway complications with an LMA versus an endotracheal tube (ETT) in patients receiving general anesthesia. Two independent reviewers identified 29 randomized prospective controlled trials that met the predetermined inclusion and exclusion criteria. The data for each individual outcome measure were combined to analyze the relative risk ratios (RRs). The Cochrane RevMan software was used for statistical analysis.

RESULTS

When an ETT was used to protect the airway, a statistically significant greater incidence of hoarse voice (RR 2.59, 95% confidence interval [CI] 1.55 to 4.34), a greater incidence of laryngospasm during emergence (RR 3.16, 95% CI 1.38 to 7.21), a greater incidence of coughing (RR 7.12, 95% CI 4.28 to 11.84), and a greater incidence of sore throat (RR 1.67, 95% CI 1.33 to 2.11) was found compared with when an LMA was used to protect the airway. The differences in the risk of regurgitation (RR 0.84, 95% CI 0.27 to 2.59), vomiting (RR 1.56, 95% CI 0.74 to 3.26), nausea (RR 1.59, 95% CI 0.91 to 2.78), and the success of insertion on the first attempt (RR 1.08, 95% CI 0.99 to 1.18) were not statistically significant between the 2 groups.

CONCLUSIONS

For the patients receiving general anesthesia, the use of the LMA resulted in a statistically and clinically significant lower incidence of laryngospasm during emergence, postoperative hoarse voice, and coughing than when using an ETT. The risk of aspiration could not be determined because only 1 study reported a single case of aspiration, which was in the group using the ETT.

The Fastrach Intubating Laryngeal Mask Airway: an overview and update

PURPOSE

To provide an evidence-based overview and update on the use of the Fastrach Intubating Laryngeal Mask Airway (FT-LMA) when used within operative and non-operative settings.

PRINCIPAL FINDINGS

The FT-LMA is available in three sizes to provide ventilation and the ability to pass an endotracheal tube (ETT) into the trachea blindly, semi-blindly, or with indirect visualization for patients over 30 kg. The Chandy maneuver is recommended routinely; the first maneuver optimizes ventilation, and the second maneuver increases success at endotracheal intubation (ETI). The manufacturer's reinforced tube or a pre-warmed or reversed standard ETT may be utilized. Insertion and ventilation are successful in almost all patients. Blind ETI is highly successful; adjuncts are generally not necessary. The FT-LMA has a proven role in the airway management of anticipated difficult operating room (OR) intubations, unanticipated OR intubations, cervical spine injuries, and limited airway access situations. Literature in the pre-hospital and emergency department settings is limited but favourable. The FT-LMA has compared favourably with fibreoptic intubation, the LMA-Classic, the laryngeal tube, and the CobraPLA. Initially, the more expensive LMA CTrach appeared to be more successful, but overall it is not. The FT-LMA airway seal pressures are excellent; serious complications are uncommon, and the FT-LMA figures prominently in most difficult airway guidelines.

CONCLUSIONS

The FT-LMA has proven to be a useful difficult airway device both within and outside of the operating room. Effective ventilation is established in nearly all cases, and blind ETI is possible in the vast majority of cases if the optimal techniques described are used. Serious complications are uncommon.

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.

Alternative airway devices for use in children requiring prehospital airway management: update and case discussion

This manuscript reviews the latest literature on alternative airways for use in children requiring prehospital airway management. Case discussions serve as a springboard for discussion of alternatives to bag-mask ventilation and endotracheal intubation for management of ventilation in infants and children in the prehospital setting. Few airway procedures have been studied with any rigor in this setting, and most of the data that are available are extrapolated from adults. Laryngeal mask airway may be the best alternative airway with the most promise to add to the armamentarium of the prehospital provider, but no controlled trial to date has been conducted.

Randomized comparison of the SLIPA (Streamlined Liner of the Pharynx Airway) and the SS-LM (Soft Seal Laryngeal Mask) by medical students

OBJECTIVE

The aim of the study was to compare the Streamlined Liner of the Pharynx Airway (SLIPA; Hudson RCI), a new supraglottic airway device, with the Soft Seal Laryngeal Mask (SS-LM; Portex) when used by novices.

METHODS

Thirty-six medical students with no previous airway experience, received manikin training in the use of the SLIPA and the SS-LM. Once proficient, the students inserted each device in randomized sequence, in two separate patients in the operating theatre. Only two insertion attempts per patient were allowed. Students were assessed in terms of: device preference; success or failure; success at first attempt and time to ventilation.

RESULTS

Sixty-seven per cent of the students preferred to use the SLIPA (95% confidence interval 49-81%). The SLIPA was successfully inserted (one or two attempts) in 94% of patients (34/36) and the SS-LM in 89% (32/36) (P = 0.39). First attempt success rates were 83% (30/36) and 67% (24/36) in the SLIPA and SS-LM, respectively (P = 0.10). Median time to ventilation was shorter with the SLIPA (40.6 s) than with the SS-LM (66.9 s) when it was the first device used (P = 0.004), but times were similar when inserting the second device (43.8 s vs 42.9 s) (P = 0.75).

CONCLUSIONS

In the present study novice users demonstrated high success rates with both devices. The SLIPA group achieved shorter times to ventilation when it was the first device they inserted, which might prove to be of clinical significance, particularly in resuscitation attempts. Although the Laryngeal Mask has gained wide recognition for use by both novice users and as a rescue airway in failed intubation, the data presented here suggest that the SLIPA might also prove useful in these areas.

New airways for resuscitation?

Over the last 15 years supraglottic airway devices (SADs), most notably the classic laryngeal mask airway (LMA) have revolutionised airway management in anaesthesia. In contrast for resuscitation, both in and outside hospital, facemask ventilation and tracheal intubation remain the mainstays of airway management. However there is evidence that both these techniques have complications and are often poorly performed by inexperienced personnel. Tracheal intubation also has the potential to cause serious harm or death through unrecognised oesophageal intubation. SADs may have a role in airway management for resuscitation as first responder devices, rescue devices or for use during patient extraction. In particular they may be beneficial as the level of skill required to use the device safely may be less than for the tracheal tube. Concerns have been expressed over the ability to ventilate the lungs successfully and also the risk of aspiration with SADs. The only SADs recommended by ILCOR in its current guidance are the classic LMA and combitube. Several SADs have recently been introduced with claims that ventilation and airway protection is improved. This pragmatic review examines recent developments in SAD technology and the relevance of this to the potential for using SADs during resuscitation. In addition to examining research directly related to resuscitation both on bench models and in patients the review also examines evidence from anaesthetic practice. SADS discussed include the classic, intubating and Proseal LMAs, the combitube, the laryngeal tube, laryngeal tube sonda mark I and II and single use laryngeal masks.

Comparison of airway management with the intubating laryngeal mask, laryngeal tube and CobraPLA by paramedical students in anaesthetized patients

BACKGROUND

Because of the importance of airway management in emergency care, alternative methods with shorter learning curves for inexperienced personnel have been looked for as a substitute for endotracheal intubation (ETI).

METHODS

We compared the success of insertion, oxygenation and ventilation of the intubating laryngeal mask (ILMA), laryngeal tube (LT) and CobraPLA (COB) in anaesthetized patients when used by paramedical students. After informed consent, 96 patients were monitored and anaesthetized for general surgery without the use of a muscle relaxant. After the induction of anaesthesia, 32 paramedical students inserted the ILMA, LT or COB in a random order and ventilated the patient for a 60-s period. The number of insertion attempts, the time needed for insertion, and oxygenation and ventilation parameters were recorded. The students gave a subjective evaluation of the airway devices after the test.

RESULTS

Twenty-four of the 32 students (75%) successfully inserted ILMA at the first attempt, compared with 14 of 32 (44%) for LT and seven of 32 (22%) for COB (P<0.001, ILMA vs. COB). One student failed to insert ILMA after all three attempts, compared with seven of 32 (21%) using LT and seven of 32 (21%) using COB (P=not significant). Oxygenation and ventilation parameters did not differ between the groups after successful insertion.

CONCLUSION

Clinically inexperienced paramedical students can successfully use ILMA in anaesthetized patients. Further investigations are warranted to study whether ILMA or LT can replace ETI in emergency airway management when used by inexperienced medical or paramedical staff.

Methoden des Atemwegsmanagements in der pr�klinischen Notfallmedizin

In the majority of emergency situations definite airway control can be achieved by endotracheal intubation with or without preceding bag valve mask ventilation. However, both techniques can fail because of many different reasons. Therefore, alternative techniques for routine anaesthesia and emergency situations are required. In the present article difficulties that may arise using bag valve mask ventilation and endotracheal intubation are discussed and an overview of available alternatives is given.

Lightwand-assisted intubation of patients in the lateral decubitus position

In some situations, patients need endotracheal intubation to maintain airway patency while they are constrained in the lateral position. In this study we compared lightwand-guided intubation of 120 randomly enrolled patients placed in the supine, right, or left lateral position. Group S patients were initially placed in the supine position, and subsequent to the artificial airway having been established they were turned to the lateral decubitus position. Group R patients were initially placed in a right decubitus position during induction and intubation. Group L patients were initially placed in a left decubitus position during induction and intubation. The duration of each intubation attempt, the total time to successful intubation, and the incidence of intubation-related intraoral injury, hemodynamic changes, and postoperative sore throat and hoarseness were recorded. Intubation took a similar length of time in the supine (14.5 +/- 13.4 s), left lateral (13.3 +/- 10.2 s), and right lateral positions (15.5 +/- 13.0 s) and resulted in a similar trend in hemodynamic changes. Patients in the lateral and supine positions revealed a comparable incidence of successful first-attempt intubation, sore throat, hoarseness, oral mucosal injury, and dysrhythmia. Insignificantly more esophageal intubations were performed in the lateral position in the first attempt at intubation; however, all patients were correctly intubated shortly after reattempting intubation. We concluded that lightwand-assisted intubation is easily performed and a similar technique may be used whether the patient is in a lateral, recumbent, or a supine position. This alternative technique should be practiced and is recommended for patients who must remain in a lateral position during intubation and surgery.

Training in airway management

Management of the airway is central to the practice of anaesthesia, yet trainees frequently feel poorly trained in this area. A large range of skills needs to be acquired, but there are often problems providing training on live patients. We review the different modalities available for training and assessment in airway management.

Intubating laryngeal mask airway

The Intubating Laryngeal Mask Airway (ILMA) was introduced into clinical practice in 1997 following numerous clinical trials involving 1110 patients. The success rate of blind intubation via the device after two attempts is 88% in "routine" cases. Successful intubation in a variety of difficult airway scenarios, including awake intubation, has been described, with the overall success rate in the 377 patients reported being approximately 98%. The use of the ILMA by the novice operator has also been investigated with conflicting reports as to its suitability for emergency intubation in this setting. Blind versus visualized intubation techniques have also been investigated. These techniques may provide some benefits in improved safety and success rates, although the evidence is not definitive. The use of a visualizing technique is recommended, especially whilst experience with intubation via the ILMA is being gained. The risk of oesophageal intubation is reported as 5% and one death has been described secondary to the complications of oesophageal perforation during blind intubation. Morbidity described with the use of the ILMA includes sore throat, hoarse voice and epiglottic oedema. Haemodynamic changes associated with intubation via the ILMA are of minimal clinical consequence. The ILMA is a valuable adjunct to the airway management armamentarium, especially in cases of difficult airway management. Success with the device is more likely if the head of the patient is maintained in the neutral position, when the operator has practised at least 20 previous insertions and when the accompanying lubricated armoured tube is used.

Airway management outside the operating room

The choice of airway device for resuscitation depends on the skill of the user, the equipment available, the conscious state of the patient, the location of the patient and the probable cause of the cardiorespiratory arrest. Extraglottic airway devices are recommended by the European and American Resuscitation Councils for use when intubation skills are lacking. In this review, we discuss recent research relevant to the use of extraglottic airway devices in resuscitation.

Prehospital and resuscitative airway care: should the gold standard be reassessed?

In the context of prehospital care and resuscitation, tracheal intubation has been regarded as the standard in airway treatment. The evidence for this status is rather weak. It does not take into account the level of training and experience of the personnel attempting intubation, and whether they use neuromuscular blockers. In unskilled hands, attempted tracheal intubation is harmful; unrecognized esophageal intubation is disastrous. When healthcare providers lack adequate skills in tracheal intubation, alternative airway devices, such as the laryngeal mask airway or the Combitube, may be better options than a simple facemask. Healthcare personnel using any of these devices should be adequately trained and maintain frequent practice.

Intubating laryngeal mask airway, laryngeal tube, 1100 ml self-inflating bag-alternatives for basic life support?

Insufficient oxygenation, ventilation and gastric inflation with subsequent regurgitation of stomach contents is a major hazard of bag-valve-face mask ventilation during the basic life support phase of cardiopulmonary resuscitation (CPR). The European Resuscitation Council has recommended smaller tidal volumes of approximately 500 ml as an effort to reduce gastric inflation; furthermore, the intubating laryngeal mask airway and the laryngeal tube have been recently developed in order to provide rapid ventilation and to secure the airway. The purpose of our study was to examine whether usage of a newly developed medium-size self-inflating bag (maximum volume, 1100 ml) in association with the intubating laryngeal mask airway, and laryngeal tube may provide adequate lung ventilation, while reducing the risk of gastric inflation in a bench model simulating the initial phase of CPR. Twenty house officers volunteered for our study. When using the laryngeal tube, and the intubating laryngeal mask airway, respectively, the medium-size (maximum volume, 1100 ml) versus adult (maximum volume, 1500 ml) self-inflating bag resulted in significantly (P<0.05) lower mean+/-S.E.M. lung tidal volumes (605+/-22 vs. 832+/-4 ml, and 666+/-27 vs. 887+/-37 ml, respectively), but comparable peak airway pressures. No gastric inflation occurred when using both devices with either ventilation bag. In conclusion, both the intubating laryngeal mask airway and laryngeal tube in combination with both an 1100 and 1500 ml maximum volume self inflating bag proved to be valid alternatives for emergency airway management in a bench model of a simulated unintubated cardiac arrest victim.