Feasibility and speed of insertion of seven supraglottic airway devices under simulated airway conditions

The placement of four different supraglottic airway devices by medical students: a manikin study

BACKGROUND AND OBJECTIVES

Although endotracheal intubation is the gold standard in airway management, this procedure requires both technical training and experience. Supraglottic airway devices are an alternative to endotracheal intubation and are simpler, less invazive, and require less time for placement compared with endotrakeal intubation. Aim of the study was to evaluate the success rates, ease of use, duration of application, and maneuver performance of different supraglottic airway devices (SADs) used by term-5 medical students on a manikin.

MATERIALS AND METHODS

This cross-sectional study was conducted in Zonguldak Bülent Ecevit University Hospital, Turkey, between April and June 2022. Term 5 Medical students (n = 111) were asked to place four different SAD [classical laryngeal mask, suprema laryngeal mask, ProSeal laryngeal mask (pLMA), I-gel] on an adult airway manikin. After the students were trained in the use of the devices, the ease of use for each, duration of successful application, success of application and use of optimization maneuvers were recorded. The participants were asked to distinguish the device they felt most confident to place and the most difficult to implement.

RESULTS

There was a significant difference between the groups in ease and duration of application (p < 0.001). The most difficult and longest application time was with pLMA and the easiest and shortest was with I-gel (p < 0.05). The number of application failure was also highest for pLMA (p < 0.001). It was found that the participants distinguished (41%) I-gel as the most confident device to use, (84%) pLMA as the most difficult device to use for airway control.

CONCLUSIONS

I-gel was found to be superior to others in terms of ease of use, duration and success of application.

A study to evaluate and compare intubating laryngeal mask airway and air-Q intubating laryngeal airway for intubation using Parker Flex Tip tube

Background and Aims

Though manufacturer recommendations suggest use of specific endotracheal tube (ETT) with intubating laryngeal mask airway (ILMA) and air-Q intubating laryngeal airway (ILA), Parker Flex Tip tube introduced by J D Parker has certain advantages and is also cost-effective. This study was conducted to compare ILMA and air-Q ILA for intubation using Parker Flex Tip tube.

Methods

Patients of either gender, aged 18-60 years, scheduled for elective surgery requiring endotracheal intubation were included in this study. In group A (n = 55), blind intubation was done through ILMA using Parker Flex Tip tube and in group B (n = 55), blind intubation was done through air-Q ILA using Parker Flex Tip tube. Success rate, number of attempts, ease and a total time of intubation were recorded.

Results

Intubation was successful in 54 patients (98.2%) in group A and in 46 patients (85.2%) in group B (P = 0.026). Intubation was significantly easy with ILMA (P = 0.048). Manoeuvres for intubation were used in 10.9% patients in group A while it was used in 27.8% patients in group B. Significantly, more manoeuvres were required with air-Q ILA for intubation (P = 0.026). Number of attempts for ETT placement (P = 0.092), insertion time of ETT (T_T) (P = 0.472) and total time taken for successful intubation (P = 0.526) were comparable in both the groups.

Conclusion

The intubating laryngeal mask airway was superior to the air-Q intubating laryngeal airway for blind intubation using Parker Flex Tip tube.

Comparison of blind intubation via supraglottic airway devices versus standard intubation during different airway emergency scenarios in inexperienced hand: Randomized, crossover manikin trial

BACKGROUND

Securing the airway and enabling adequate oxygenation and ventilation is essential during cardiopulmonary resuscitation (CPR). The aim of the study was to evaluate the success rate of blind intubation via the I-Gel and the Air-Q compared with direct laryngoscopy guided endotracheal intubation by inexperienced physician and to measure time to successful intubation.

METHODS

The study was designed as a randomized, cross-over simulation study. A total of 134 physicians, from specialties other than Anesthesia or Emergency Medicine, who considered themselves skilled in endotracheal intubation but who have never used any kind of supraglottic airway device performed blind intubation via the I-Gel and Air-Q and direct laryngoscopy guided endotracheal intubation in 3 randomized scenarios: normal airway without chest compression during intubation attempt; normal airway with continuous chest compression during intubation attempt; difficult airway with continuous chest compression.

RESULTS

Scenario A: Success rate with initial intubation attempt was 72% for endotracheal intubation, 75% in Air-Q, and 81% in I-Gel. Time to endotracheal intubation and ease of intubation was comparable with all 3 airway devices used. Scenario B: Success rate with the initial intubation attempt was 42% for endotracheal intubation, compared with 75% in Air-Q and 80% in I-Gel. Time for endotracheal intubation was significantly prolonged in endotracheal intubation (42 seconds, 35-49), compared with Air-Q (21 seconds, 18-32) and I-Gel (19 seconds, 17-27). Scenario C: The success rate with the initial intubation attempt was 23% in endotracheal intubation, compared with 65% in Air-Q and 74% in I-Gel. Time to intubation was comparable with both supraglottic airway devices (20 vs 22 seconds) but was significantly shorter compared with endotracheal intubation (50 seconds, P < .001).

CONCLUSIONS

Less to moderately experienced providers are able to perform endotracheal intubation in easy airways but fail during ongoing chest compressions and simulated difficult airway. Consequently, less to moderately experienced providers should refrain from endotracheal intubation during ongoing chest compressions during CPR and in expected difficult airways. Supraglottic airway devices are reliable alternatives and blind intubation through these devices is a valuable airway management strategy.

Performance and skill retention of five supraglottic airway devices for the pediatric difficult airway in a manikin

Supraglottic airway devices (SADs) have been introduced to assist medical professionals in emergency situations with limited experience in securing airways via conventional endotracheal intubation (ETI). Literature on the use of SADs for securing an airway during pediatric critical settings is scarce, and there is a lack of studies comparing different SADs to each other and to conventional ETI. We conducted a study comparing five different SADs to ETI with regard to success rate, time to first ventilation, and personal rating in a pediatric manikin under simulated physiologic and pathologic airway conditions in 41 pediatricians of varying clinical experience and training. Only the AirQ, AuraG, and laryngeal tube (LT) were inserted within 30 s correctly by all participants under physiologic conditions. In tongue edema (TE), AirQ and LT had the highest success rate. In limited mobility of the cervical spine (CS), AirQ, AuraG, and LT again all were inserted within 30 s. In a multivariate analysis, factors influencing the success were experience with the respective device and level of medical education. Under TE conditions, there were significantly longer insertion times for the ETI, laryngeal mask airway (LMA), and EzT. Under CS conditions, there were significantly longer insertion times for the ETI, LMA, LT, and EzT. A multivariate analysis showed experience with the respective device to be the only factor of influence on time to first ventilation.

CONCLUSION

LT, AuraG, and AirQ were superior in providing fast and effective ventilation during simulated difficult airway situations in pediatricians. What is Known: • Supraglottic airway devices have been introduced for medical professionals who lack experience for managing difficult airway situations. • A variety of these devices have been developed so far, but not compared to each other yet. What is New: • We compared five different supraglottic airway devices with regard to success rate, time to first ventilation, and personal rating in a pediatric manikin under simulated physiologic and pathologic airway conditions. • Laryngeal tube, AuraG, and AirQ were superior in providing fast and effective ventilation during simulated difficult airway situations in pediatricians with varying clinical experience.

Streamlined Liner of the Pharynx Airway: Randomised Comparison of Size Selection Strategies with Regard to Patient Height versus Thyroid Cartilage Width

Introduction

Streamlined Liner of the Pharynx Airway (SLIPA) is a disposable supraglottic airway. There are two strategies to select the size of SLIPA: by height and width of thyroid cartilage. This study compared the utility of the two strategies in selecting the optimal size.

Methods

One hundred forty-two patients were randomly divided into two groups with size selection by height (H) and the maximal width of the thyroid cartilage (T). The SLIPA size was selected by height in group H, and by the width of thyroid cartilage in group T. After inserting SLIPA, the investigator made note of the oropharyngeal leakage pressure (OLP) and the degree of insertion difficulty. We set the OLP as a primary outcome. In cases of an OLP <15 cmH2O, the investigator manipulated the apparatus to try to reposition it. If air still leaked, another attempt was made using a SLIPA one size larger until an OLP >15 cmH2O was achieved in up to three attempts. After insertion, the investigator measured the inspiratory and expiratory tidal volume. Post-operatively, the presence of blood or regurgitated fluid on the device was evaluated.

Results

OLP for group T was higher than that of group H (p=0.009). The need for manipulation and the leak fraction was higher in group H than in group T (p=0.008 and 0.034, respectively). The degree of insertion difficulty, number of trials and incidence of blood and regurgitated fluid on the device were similar between the two groups.

Conclusions

Both the width and height of thyroid cartilage can be used for selecting the optimal SLIPA size. (Hong Kong j.emerg.med. 2015;22:303-311)

Inter-center comparison of EasyTube and endotracheal tube during general anesthesia in minor elective surgery

Background

The EasyTube^® (EzT) is a supraglottic airway device (SAD) enabling ventilation irrespective of its placement into the esophagus or trachea. Data obtained on SADs from multicenter studies, performed in highly specialized centers cannot always be transferred to other sites. However, data on comparability of different sites are scarce. This study focused on inter-site variability of ventilatory and safety parameters during general anesthesia with the EzT.

Methods

400 patients with ASA physical status I-II undergoing general anesthesia for elective surgery in four medical centers (EzT group (n = 200), ETT group (n = 200)). Mallampati classification, success of insertion, insertion time, duration of ventilation, number of insertion attempts, ease of insertion, tidal volumes, leakage, hemodynamic parameters, oxygenation, and complications rates with the EasyTube (EzT) or endotracheal tube (ETT) in comparison within the sites and in between the sites were recorded.

Results

Intra-site and inter-site comparison of insertion success as primary outcome did not differ significantly. The inter-site comparison of expiratory minute volumes showed that the volumes achieved over the course of anesthesia did not differ significantly, however, mean leakage at one site was significantly higher with the EzT (0.63 l/min, p = 0.02). No significant inter-site differences in heart rate, blood pressure, or oxygenation were observed. Sore throat and blood on the cuff after removal of the device were the most frequent complications with significantly more complications at one site with the EzT (p = 0.01) where insertion was also reported significantly more difficult (p = 0.02).

Conclusion

Performance of the EzT but not the ETT varied between sites with regard to insertion difficulty, leakage, and complications but not insertion success, ventilation, hemodynamics, and oxygenation parameters in patients with ASA physical status 1–2 during general anesthesia undergoing minor elective surgery.

The EasyTube during general anesthesia for minor surgery: A randomized, controlled trial

BACKGROUND

The EasyTube (EzT) is a supraglottic airway device that is used for emergency airway situations. Ventilation during general anesthesia should also be feasible, but literature on the EzT is scarce. We evaluated the EzT in comparison with the endotracheal tube (ETT) in its use during general anesthesia in a comparative study.

METHODS

A total of 400 patients with American Society of Anesthesiologists (ASA) physical status I to II scheduled for minor surgery in 4 centers were randomized for ventilation via the ETT or EzT.

RESULTS

In all patients, the EzT and the ETT could be inserted within 3 attempts. In all EzT patients, the inspiratory and expiratory minute volumes (6.64 ± 0.71 and 6.34 ± 0.69 L/min) were sufficient to reach target oxygenation values, similar to ETT patients (P  =  .59). Mean peak pressure, mean plateau pressure, and mean dynamic compliance did not differ between the groups. Sore throat and blood on the cuff after removal were the most frequent complications in both groups.

CONCLUSION

Ventilation for up to 1 hour during general anesthesia in patients with ASA physical status I to II with the EzT is feasible and safe.

Supraglottic Airway Devices: the Search for the Best Insertion Technique or the Time to Change Our Point of View?

In the crowded world of supraglottic airway devices (SADs), many papers compare the easiness of insertion based on the different endpoints of an operator's satisfaction: first pass success, ventilation effectiveness, complications and morbidity. Proseal LMA^™ (Laryngeal Mask Airway, Teleflex Medical, Dublin, Ireland) has been extensively studied because on one hand it has a steeper learning curve and more complex insertion when compared with other SADs and on the other hand many alternative techniques are available to facilitate insertion. This research is part of a larger body of studies exploring the issue that some devices are more difficult to insert because of many features related to sizing, constructive material, airway conduit and cuff design, performance and last but not least experience. Nevertheless, the biggest question might be the search for a systematic categorization of insertion difficulty features and identification of criteria allowing the choice for the best device and consequently for the best insertion technique. Given that, as a result of many intrinsic characteristics of the device we are using, insertion might become the secondary issue to be considered only after we clearly identify what makes it difficult, and to be counterbalanced on the results we expect from the device, performance we can achieve and degree of airway protection it could grant. The aim of this narrative review is to consider which factors might affect or condition SAD insertion difficulty and to try identifying some criteria addressing physicians pertaining to the use of SADs in clinical practice.

Comparison of the i-gel and other supraglottic airways in adult manikin studies: Systematic review and meta-analysis

BACKGROUND

The i-gel has a gel-like cuff composed of thermoplastic elastomer that does not require cuff inflation. As the elimination of cuff inflation may shorten insertion time, the i-gel might be a useful tool in emergency situations requiring prompt airway care. This systematic review and meta-analysis of previous adult manikin studies for inexperienced personnel was performed to compare the i-gel with other supraglottic airways.

METHODS

We searched PubMed, the Cochrane Library, and EMBASE for eligible randomized controlled trials (RCTs) published before June 2015, including with a crossover design, using the following search terms: "i-gel," "igel," "simulation," "manikin," "manikins," "mannequin," and "mannequins." The primary outcomes of this review were device insertion time and the first-attempt success rate of insertion.

RESULTS

A total of 14 RCTs were included. At the initial assessment without difficult circumstances, the i-gel had a significantly shorter insertion time than the LMA Classic, LMA Fastrach, LMA Proseal, LMA Unique, laryngeal tube, Combitube, and EasyTube. However, a faster insertion time of the i-gel was not observed in comparisons with the LMA Supreme, aura-i, and air-Q. In addition, the i-gel did not show the better results for the insertion success rate when compared to other devices.

CONCLUSION

The findings of this meta-analysis indicated that inexperienced volunteers placed the i-gel more rapidly than other supraglottic airways with the exception of the LMA Supreme, aura-i, and air-Q in manikin studies. However, the quicker insertion time is clinically not relevant. The unapparent advantage regarding the insertion success rate and the inherent limitations of the simulation setting indicated that additional evidence is necessary to confirm these advantages of the i-gel in an emergency setting.

Comparison of blind intubation through supraglottic devices and direct laryngoscopy by novices: a simulation manikin study

OBJECTIVE

This study aimed to compare intubation performance between blind intubation through supraglottic airway devices and direct laryngoscopy by novices under manikin simulation. We hypothesized that the intubation time by novices using supraglottic airway devices was superior to that with the Macintosh laryngoscope (MCL).

METHODS

A prospective, randomized crossover study was conducted with 95 participants, to evaluate i-gel, air-Q, LMA Fastrach, and MCL devices. Primary outcomes were the intubation time and the success rate for intubation.

RESULTS

The i-gel showed the shortest insertion and tube passing time among the four devices; the i-gel and air-Q also showed the shortest total intubation time (all P<0.0083; i-gel vs. air-Q, P=0.03). The i-gel and MCL showed the highest cumulative success rate (all P<0.0083; i-gel vs. MCL, P=0.12).

CONCLUSION

Blind intubation through the i-gel showed almost equal intubation performance compared to direct laryngoscopy.

The Easytube for airway management: a systematic review of clinical and simulation studies

STUDY OBJECTIVE

Endotracheal intubation is considered the criterion-standard technique for securing the airway. Supraglottic airway devices (SADs) represent a major advance in airway management and are recommended by the guidelines in difficult situations such as Advanced Life Support and "cannot ventilate-cannot intubate" scenarios. The Easytube (EzT) is an SAD introduced a decade ago but not included yet in the above guidelines.

DESIGN

Systematic review of MEDLINE and EMBASE according to PRISMA guidelines available up to January 12, 2016.

SETTING

We collected experimental and clinical evidence regarding EzT positioning performed by medial students, anesthesiologists, paramedics, or nurses.

PATIENTS

Manikins, cadavers, or patients.

INTERVENTIONS

EzT positioning in both clinical and simulation studies, both under standard and under difficult scenarios.

MEASUREMENTS

Time to insertion and time to ventilation, success rate and operator's assessment of the device, change in ventilatory parameters, and major complications.

MAIN RESULTS

Fifteen manuscripts were found: 6 prospective clinical studies and 9 conducted under experimental conditions (7 with a simulator and 2 on cadavers). The EzT inserted by both inexperienced and experienced personnel in most studies had high success rate, and it showed excellent results also during simulated cardiopulmonary resuscitation and in difficult airway scenarios. The EzT had better ventilatory parameters as compared with the Combitube and showed great airway sealing capacity, comparable to the Combitube and to the laryngeal mask airway and superior to other SADs. EzT allowed the insertion of large nasogastric tubes and has only mild adverse effects like other SADs. No major complications were described.

CONCLUSION

The EzT appears to be a safe and a good alternative to established SADs. It may be considered among SADs by future guidelines on Advanced Life Support and "cannot ventilate-cannot intubate" scenarios.

Preheating of streamlined liner of pharyngeal airway (SLIPA) reduced the related complications: a randomized control study

This study was designed to verify whether preheating could decrease the complications that may be associated with the use of streamlined liner of pharyngeal airway (SLIPA). We evaluated the incidence of sore throat, maximum sealing pressure, hoarseness and blood stains after preheating of SLIPA. Eighty patients scheduled for hysteroscopic surgery to whom the SLIPA was considered suitable were randomly allocated to preheating group or control group. The SLIPA in preheating group was placed in the incubator at 42 °C. The control group temperature was 24 °C. The mean maximum sealing pressure and duration of insertion were compared. Patients were interviewed at recovery room about sore throat and other complications. There were statistical differences in incidence of sore throat, severity of sore throat and blood stains between groups. However there was no statistical difference in the maximum sealing pressure. Our results suggest preheating of the SLIPA decreased the complications related with the insertion of SLIPA. Clinical Trials.gov Identifier NCT02539485.

Concluding results from the first phase of the Zurich Unexpected Difficult Airway course based on exercise of technical skills

We analysed the results of the first phase of the Zurich Unexpected Difficult Airway course. Two hundred and twenty-eight staff members performed a total of 2712 standardised airway rescue procedures with four airway devices: SensaScope™, LMA Fastrach™, Laryngeal Tube and needle cricothyrodotomy. Four consecutive attempts were performed using each device. We analysed the success rate and the time needed for successful completion for each attempt and device. The success rates and mean (SD) completion times for all participants were 96.2% and 30.2 (15.3) s for the SensaScope, 88.1% and 40.4 (17.2) s for the LMA Fastrach, 99.0% and 12.1 (10.6) s for the Laryngeal Tube and 99.0% and 12.3 (6.1) s for needle cricothyroidotomy. The learning curves resulting from the four consecutive attempts with each device showed a clear pattern of improvement. This institutional airway training course represents a promising method to improve the capability of practitioners to cope with unexpected difficult airway situations.

Alternative airways for the pediatric emergency department

Securing the pediatric airway in the emergency setting is an uncommon event that is complicated by anatomic, physiologic, and environmental factors. Even more uncommonly, practitioners are faced with the added complication of a difficult airway, and the question of what alternatives to traditional endotracheal intubation are available and most useful may arise. Timely and effective intervention determines the patient's clinical outcome. The purpose of this review was to detail specific alternative airway management strategies and tools for use in the pediatric emergency department.

A comparative study among normal saline, water soluble gel and 2% lidocaine gel as a SLIPA lubricant

BACKGROUND

This study was designed to find appropriate lubricant for streamed lined liner of pharyngeal airway™ (SLIPA™). We evaluated the incidence of sore throat, nausea, vomiting, hoarseness, paresthesia and blood stain after using saline, water soluble gel and 2% lidocaine gel as a SLIPA™ lublicant.

METHODS

One hundred twenty three patients scheduled for minor surgery to whom the SLIPA™ was considered suitable were randomly allocated to one of three groups which receive normal saline, water soluble gel or 2% lidocaine gel as a SLIPA™ lublicant. Patients were interviewed at recovery room, post operation 6-12 hour, post operation 18-24 hour about sore throat and other complications.

RESULTS

There were no statistical difference in sore throat and blood stain among three groups. Also there were no statistical differences in hoarseness, nausea, vomiting. The incidence of paresthesia in 2% lidocaine gel group was significantly higher than those of the other two groups immediately after operation, but it was resolved after leaving the recovery room.

CONCLUSIONS

Our results suggest that normal saline, water soluble gel and 2% lidocaine gel are all available as a SLIPA™ lubricant. Size of SLIPA™, insertion technique and difficulty of insertion should be further investigated as the main causes of a sore throat and other complications which can occur after the insertion of SLIPA™.