Supraglottic Airway Devices Research Articles

Laryngeal tube suction for airway management during in-hospital emergencies

OBJECTIVE:The role of supraglottic airway devices in emergency airway management is highlighted in international airway management guidelines. We evaluated the application of the new generation laryngeal tube suction (LTS-II/LTS-D) in the management of in-hospital unexpected difficult airway and cardiopulmonary resuscitation.METHODS:During a seven-year period, patients treated with a laryngeal tube who received routine anesthesia and had an unexpected difficult airway (Cormack Lehane Grade 3-4), who underwent cardiopulmonary resuscitation, or who underwent cardiopulmonary resuscitation outside the operating room and had a difficult airway were evaluated. Successful placement of the LTS II/LTS-D, sufficient ventilation, time to placement, number of placement attempts, stomach content, peripheral oxygen saturation/end-tidal carbon dioxide development (SpO2/etCO2) over 5 minutes, subjective overall assessment and complications were recorded.RESULTS:In total, 106 adult patients were treated using an LTS-II/LTS-D. The main indication for placement was a difficult airway (75%, n=80), followed by cardiopulmonary resuscitation (25%, n=26) or an overlap between both (18%, n=19). In 94% of patients (n=100), users placed the laryngeal tube during the first attempt. In 93% of patients (n=98), the tube was placed within 30 seconds. A significant increase in SpO2 from 97% (0-100) to 99% (5-100) was observed in the whole population and in cardiopulmonary resuscitation patients. The average initial etCO2 of 39.5 mmHg (0-100 mmHg) decreased significantly to an average of 38.4 mmHg (10-62 mmHg) after 5 minutes. A comparison of cardiopulmonary resuscitation patients with non-cardiopulmonary resuscitation patients regarding gastric contents showed no significant difference.CONCLUSIONS:LTS-D/LTS-II use for in-hospital unexpected difficult airway management provides a secure method for primary airway management until other options such as video laryngoscopy or fiber optic intubation become available.

Comparison of I-gel with Baska Mask Airway for Controlled Ventilation in Obese Patients Undergoing Ambulatory Surgery: A Prospective Randomized Trial

The ideal supraglottic airway device must have high airway seal pressures during spontaneous and positive pressure ventilation also low resistance to the flow of gases. This study compared the utility of I-Gel with Baska Mask during general anesthesia in obese patients undergoing elective ambulatory surgeries. The study was conducted on sixty obese patients with body mass index (BMI) of ≥ 25 and ≤ 40 kg.m2, ASA I, II, III, 18-60 years old of either sex scheduled for short duration (<3 hr). I-gel was successfully inserted in 25 patients on the first attempt and in 2 patients on the second attempt (overall success rate = 90%). Baska mask was successfully inserted in 27 patients on the first attempt and in 2 patients on the second attempt (overall success rate = 96.97%). Successful insertion time was significantly shorter in the I-gel group. Oropharyngeal sealing pressure (OSP) was significantly higher following Baska mask insertion. Intra- and postoperative airway morbidity rates were not significantly different between both groups. So Concluded that both I-gel and Baska mask are suitable for ventilation in obese patients, but Baska mask gave a better laryngeal seal.

救急/集中治療領域のdifficult airway managementにおける声門上器具 &amp;mdash;その役割を再考する

救急/集中治療領域で気管挿管困難症に遭遇する確率は手術室より遥かに高く，かつ気道確保の失敗は致命的な結果を招く。一刻の猶予も許されない状況で使用するレスキューデバイスは「迅速，単純，容易」に操作できなければならない。声門上器具はこれらの観点からはほぼ理想的なデバイスであり，近年麻酔科領域のみならず，救急/集中治療領域のdifficult airway management（DAM）でもその有用性を示す報告が増加している。しかし，本邦の救急/集中治療領域における声門上器具の普及率は諸外国に比して低く，現状では声門上器具が適切に配備されているとは言い難い。一刻を争う事態での安全を確保するために，声門上器具を含め，平時より適切なDAMデバイスを配備し運用しておくことが望まれる。本稿を通し，救急/集中治療領域のDAMにおける声門上器具の役割を再考する。

융복합적 기술이 적용된 성문위기구들의 삽관용이성 비교

융복합적 기술이 적용된 성문위기구들의 삽관용이성 비교

English

INTRODUCTION: Anaesthesia has made major advances in recent years. Considerable efforts have been devoted to airway management by the anesthesiologist during the past 20 years. A large number of supraglottic airway devices have been introduced recently. The original purpose was to reduce the need for more invasive methods of airway management while offering a more reliable alternative to the facemask. The laryngeal mask airway (LMA) is one such innovative device designed for airway management. One of the principal aims of anaesthesia is to counter surgically induced stress. So the anesthesiologist should be able to use a method of delivering the anaesthetic that is by itself not stress inducing3. Since the LMA is placed directly over the posterior pharynx, it avoids tracheal stimulation and hence the systemic and ocular stress response associated with tracheal intubation. AIM OF THE STUDY: The aim of the study is to observe the usefulness of Midazolam and mini-dose of Succinyl choline to facilitate the insertion of laryngeal mask airway during Propofol anesthesia in elective general surgery patients based on the following parameters. 1. Conditions during insertion of laryngeal mask airway such as jaw relaxation, ease of insertion, number of attempts for insertion, airway trauma and total dose of Propofol. 2. Patient’s response to insertion of laryngeal mark airway such as gagging, coughing, head and limb movements, laryngospasm, etc. 3. Hemodynamic parameters like mean arterial pressure, heart rate and oxygen saturation. MATERIALS AND METHODS: After obtaining institutional ethical committee clearance and the patient consent, the study was carried out on 75 patients posted for elective surgical procedures lasting less than or equal to 45 min at Madras Medical College & GGH, Chennai. Patients belonging to the age group of 18 – 50 years of both the sexes were selected. Inclusion Criteria: 1. Elective short surgical procedures lasting less than or equal to 45 min Patients of ASA physical status I and II, 2. Aged between 18 – 50 years of both sexes. Exclusion Criteria: 1. Patients with full stomach ,pregnant patient, 2. Patients posted for emergency surgery, 3. Patients with oral, peri oral pathology such as tumours, abscess or grossly enlarged tonsils. OBSERVATIONS AND RESULTS: This study was conducted on 75 patients who were divided into 3 Groups of 25 patients each. Group A - Propofol Group, Group B - Propofol with midazolam Group, Group C - Propofol with succinyl choline Group. Demographic Profile: In group A and C, 48% of patients are males and rest 52% are females, while in group B 52% of patients are males and rest females. The mean age of patient is 30.52, 30.12 and 30.84 in groups A, B and C respectively. The mean weight is 51.8, 53 and 53.22 in groups A, B and C respectively. Patients in each group were statistically comparable in relation to sex, age and weight. SUMMARY: In this study, the conditions of LMA insertion, patient’s response to LMA insertion and the hemodynamic changes during and after LMA insertion in the following three groups of patients were observed. Group A - Inj. Propofol 2.5mg/kg only. Group B - Inj. Propofol 2.5 mg/kg + 0.04mg/kg midazolam. Group C- Inj. Propofol 2.5 mg/kg + 0.1 mg/kg succinyl choline. • The jaw relaxation was adequate in 100% of Group B patients compared to 32 % of patients in Group A and 64% in Group C. • Overall insertion conditions were excellent in 100% of patients in Group B compared to 32% in Group A and 44% in Group C. • LMA was inserted successfully in the first attempt in 100% of patients in Group A compared to 40% in Group A and 64% in Group C. • Airway trauma as evidenced by blood staining of LMA was found in 36% of patients in Group A and 32% in Group C while none of the patients in Group B had any airway trauma. • Post op myalgia was present in 40% of patients in Group C. • Patient movements were present in 48% of patients in Group A compared to 12% in Group C while no movement was present in any of the patient in Group B. • The total dose of Propofol required for successful insertion of LMA was 2.76mg/kg in Group A and 2.60 mg/kg in Group C, while it is the least 2.06mg/kg in Group B which is the cause of significant hemodynamic stability in patients of Group B CONCLUSION: To conclude, addition of Midazolam (0.04mg/kg) to the standard dose of propofol provides better LMA insertion conditions than the addition of mini-dose Succinyl Choline (0.1mg/kg).

Randomised Comparison of the Effectiveness of the Laryngeal Mask Airway Supreme, I-Gel and Current Practice in the Initial Airway Management of Out of Hospital Cardiac Arrest

(Abstracted from Br J Anaesth, 116(2):262–268, 2016) Effective ventilation is a crucial component of cardiopulmonary resuscitation (CPR) after cardiac arrest, but what constitutes effective ventilation is unclear. Although tracheal intubation has traditionally been viewed as the best airway management during out-of-hospital cardiac arrest (OHCA), this assumption has been challenged by the use of supraglottic airway devices (SGAs), which are faster and easier to insert.

Comparison of the Macintosh laryngoscope and blind intubation via the iGEL for Intubation With C-spine immobilization: A Randomized, crossover, manikin trial

IntroductionEndotracheal intubation (ETI) using a Macintosh laryngoscope (MAC) requires the head to be positioned in a modified Jackson position, slightly reclined and elevated. Intubation of trauma patients with an injured neck or spine is therefore difficult, since the neck usually cannot be turned or is already immobilized in order to prevent further injury. The iGEL supraglottic airway seems optimal for such conditions due to its blind insertion without the need of a modified Jackson position. MethodsProspective, randomized, crossover study in 46 paramedics. Participants performing standard intubation and blind intubation via iGEL supraglottic airway device in three airway scenarios: Scenario A – normal airway; Scenario B - manual inline cervical immobilization, performed by an independent instructor; scenario C: cervical immobilization using a standard Patriot cervical extraction collar. ResultsIn Scenario A, nearly all participants performed ETI successfully both with MAC and iGEL (100% vs. 95.7%). The time to intubation (TTI) using the MAC and iGEL amounted to 19 [IQR, 18–21]s vs. 12 [IQR, 11–13]s (P<0.001). Head extension angle as well as tooth compression were significantly better with the iGEL compared to the MAC (P<0.001). In scenario B and C, the results with the iGEL were significantly better than with MAC for all analyzed variables (TTI, success of first intubation attempt, head extension angle, tooth compression and VAS scores). ConclusionWe showed that blind intubation with the iGEL supraglottic airway was superior to ETI performed by paramedics in a simulated cervical immobilization scenario in a manikin in terms of success rate, time to definite tube placement, head extension angle, tooth compression, and rating.

The Effects of Endotracheal Tube and i-gel® Supraglottic Airway Device on Respiratory Impedance: A Prospective Observational Study.

BackgroundThe forced oscillation technique (FOT) is a non-invasive means of measuring respiratory resistance and reactance. We tested our hypothesis that endotracheal intubation would cause more substantial preoperative increases in FOT parameters than a supraglottic airway device (SGD).MethodsForty patients requiring general anesthesia and mechanical ventilation for transurethral bladder tumor resection underwent spirometry the day before surgery. Forced oscillation was measured using a MostGraph-01 device the day before surgery and immediately after removal of the airway adjunct. Changes in respiratory resistance and reactance were compared between those intubated and those who used SGD.ResultsThe trachea was intubated in 23 patients and SGD was used in the remaining 17 patients. Both airway adjuncts caused significant increases in preoperative respiratory resistance and reactance; however, the magnitude of the changes was significantly greater in the intubated patients.ConclusionsThe SGD appears to cause less pulmonary injury than tracheal intubation. Further study is needed to illuminate the influence of mechanical ventilation, and longer-term consequences and clinical significance of the changes we found in this study. Spontaneous ventilation through an SGD may be preferable in patients with severe respiratory disease.

Abstract 12806: Advanced Airway Management May Not be Effective Compared to Basic Airway Management After Pediatric Out-of-hospital Cardiac Arrest

Introduction: Respiratory care for pediatric out-of-hospital cardiac arrest (OHCA) may play an important role due to the asphyxial nature of the majority of pediatric OHCA events. Hypothesis: We assessed the hypothesis that prehospital advanced airway management (endotracheal intubation or supraglottic airway device) is associated with an increased chance of favorable outcomes compared with basic airway management (bag-valve-mask ventilation) after pediatric OHCA. Methods: This was a nationwide, population-based, propensity score-matched study of pediatric OHCA in Japan from January 1, 2011, to December 31, 2012, based on data from the All-Japan Utstein Registry. We included pediatric patients aged &lt; 18 years. Infants (≤ 1 year old) were excluded. The primary outcome was a favorable neurological state one month after OHCA defined as a Glasgow-Pittsburgh cerebral performance category (CPC) score of 1-2 (corresponding to a Pediatric CPC score of 1-3). The secondary outcomes included a neurologically favorable survival with a CPC score of 1 (corresponding to a Pediatric CPC score of 1), one-month survival, and prehospital return of spontaneous circulation (ROSC). Results: A total of 2,157 patients were included in the final cohort; 365 received advanced airway management and 1,792 received basic airway management. Among 2,157 patients, 213 (9.9%) survived with a favorable neurological status one month after OHCA. There were no significant differences in neurologically favorable survival between the advanced airway management group and the basic airway management group after adjusting for potential confounders: propensity score matching, OR 0.74 (95%CI 0.35-1.59), and multivariable logistic regression modeling, OR 0.55 (95% CI 0.24-1.14). Similar findings were observed for the secondary outcomes. In subgroup analyses (including the non-cardiac [mainly asphyxial] etiology group), there were no subgroups in which advanced airway management was associated with neurologically favorable survival. Conclusions: In conclusion, advanced airway management was not associated with an increased chance of neurologically favorable survival, one-month survival, or prehospital ROSC compared to basic airway management after pediatric OHCA.

Comparative Study of laryngeal mask airway Supreme and laryngeal mask airway Classic in paralyzed patients

Aim and Objectives: The present study was undertaken to compare the LMA Classic with LMA Supreme in assessing the ease of insertion, number of attempts, time for insertion, any unwanted responses, stability of device, peak airway pressure, leak volume and leak fraction and postoperative complications. Methods: A total of 274 patients of ASA grade 1 and 2 were included in the study and divided into two groups with 137 patients in each group: the LMA Classic group (group C) and LMA Supreme group (group S). All patients were induced with propofol 2.5 mg/kg and atracurium 0.5mg/kg after that appropriate sized supraglottic airway device was inserted. The ease of insertion, number of attempts, duration of insertion, stability of device, peak airway pressure, leak volume and leak fraction and postoperative complications were recorded. Results: The insertion of Supreme LMA was very easy in 134 patients and was easy in 3 patients, difficult in 0 patients while the insertion of Classic LMA was very easy in 122 patients, easy in 15 patients and difficult in 0 patients. The first attempt insertion rate was more with Supreme LMA as compared to Classic LMA. The mean duration of insertion was significantly lower with Supreme LMA than with Classic LMA. The mean airway pressure was similar in both groups. Both devices were stable. Leak volume and Leak fraction was significantly higher in Classic LMA than Supreme LMA. Peri-operative complications were not significantly different between Supreme LMA and Classic LMA. Conclusions: The LMA Supreme is superior to the LMA Classic because of its ease of insertion with lesser leak volume and leak fraction and better first attempt insertion rate.

Continuous ventilation during intubation through a supraglottic airway device guided by fiberoptic bronchoscopy: a observational assessment.

supraglottic airway devices remain, despite advances in video laryngoscopy, important tools in the management of unexpected difficult airways. Intubation through a functioning supraglottic airway device with the aid of a fiberoptic bronchoscope is a well-known technique usually performed in apnoea. With a simple modification, the patient can be ventilated during this procedure. In this observational study, Tracheal intubation Assisted by Bronchoscopy And Sad during Continuous Oxygenation (TABASCO) was performed as part of department training routine in 26 elective, fasted patients. A supraglottic airway device was used as a conduit for an endotracheal tube. All patients were easily intubated and ventilation was maintained during the procedure. The gap between the outer diameter of the fiberoptic bronchoscope and the inner diameter of the endotracheal tube was more than 2 mm in 25 of 26 patients. Effective ventilation was confirmed by clinical signs, capnography and pressure-volume curves. No signs of airtrapping occurred. No adverse events were observed during this form of airway management in this small series of elective and fasted patient when performed by an anaesthesiologist experienced in fiberoptic intubation. A gap between fiberoptic bronchoscope and endotracheal tube inner lumen seems to be prerequisite for easy ventilation through the supraglottic airway. In trained hands, this technique can be a means to secure an airway with an intubating bronchoscope without pausing ventilations. A prerequisite for this is a well-functioning supraglottic airway device.

Which Videolaryngoscope Should We Use in Airway Management?

Aim of review: This review elaborates on the role of different videolaryngoscopes in modern airway management and whether the outcomes of studies on patients and on manikins help anesthesiologists in determining which videolaryngoscope we should prefer.Methods: We reviewed the articles comparing the performance of different videolaryngoscopes published in the last decade.Recent findings: Airway problems that occur during the introduction of general anesthesia in the operating theatre, prehospital, emergency department and intensive care setting are commonly managed by skilled anesthesiologists. However, anticipated and unanticipated difficult airways do occur. Very seldom do these difficult airways result in a can't ventilate-can't intubate scenario, with potential death and brain damage as devastating outcomes. Standard Macintosh Laryngoscopy (SML) has its limitations, with Cormack-Lehane grade III-IV and percentage of glottic opening (POGO) scores of 0 being called difficult laryngoscopy. Percent of Intubation success with the direct classic Macintosh blade laryngoscopy (DML), without the use of adjuncts, is often limited to 90% (95% with adjuncts and extra manoeuvers). Videolaryngoscopy offers superiority over direct laryngoscopy as it allows an improved view of the larynx (Cormack-Lehane grade I-II; POGO 50-100%) and results in an almost 100% intubation success rate with decreased intubation time. In the rare event that an intubation attempt with a Macintosh blade videolaryngoscope (VLS) is not successful, acute angled blades can be used, or a combination technique offers an alternative. The market offers several videolaryngoscopes with alternative options (channelled, non-channelled, acute angled and Macintosh blades), each with their own indications. At this moment, there is no videolaryngoscope available which offers a solution for all problems. With our review we hope to determine the scope, based on publications in the last decade.Summary: Videolaryngoscopes have improved airway management and reduced airway related morbidity and mortality by improving the glottic view (laryngoscopy) and first attempt intubation success. Videolaryngoscopy is useful in video-guided insertion of endotracheal tubes, supraglottic airway devices, temperature probes and nasogastric tubes. However, not all videolaryngoscopes are created equally as there are definite differences which anesthesiologists must be aware of in order to make the best choice for individual patients. This review concluded that the most favored videolaryngoscope was the Pentax-Airway Scope of the channelled videolaryngoscopes and the Karl Storz C-MAC of the non-channelled videolaryngoscopes. However, the C-MAC VLS is the most versatile and can be used for direct and indirect laryngoscopy. Citation: Andre van Zundert, Cienwen Town, Lizanne Dagleish, Heather Reynolds. Which videolaryngoscope should we use in airway management? J Anesth Perioper Med 2016; 3: 247-57. doi: 10.24015/JAPM.2016.0034This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

A new laryngeal mask supraglottic airway device with integrated balloon line: a descriptive and comparative bench study.

Laryngeal masks are invasive devices for airway management placed in the supraglottic position. The Shiley™ laryngeal mask (Shiley™ LM) features an integrated inflation tube and airway shaft to facilitate product insertion and reduce the chance of tube occlusion when patients bite down. This study compared the Shiley LM to two other disposable laryngeal mask devices, the Ambu® AuraStraight™ and the LMA Unique™. Overall device design, tensile strength, flexibility of various structures, and sealing performance were measured. The Shiley LM is structurally stronger and its shaft is more resistant to compression than the other devices. The Shiley LM is generally less flexible than the other devices, but this relationship varies with device size. Sealing performance of the devices was similar in a bench assay. The results of this bench study demonstrate that the new Shiley LM resembles other commercially available laryngeal mask devices, though it exhibits greater tensile strength and lower flexibility.

Laryngeal Mask Airway Supreme in Children: A Retrospective Audit

Background: The laryngeal mask airway (LMA) Supreme (LMAS) is a sophisticated, second-generation supraglottic airway device, with an improved seal, and gastric access. It is a capable device for use in more complex procedures and in younger children. No study has been able to analyze a large pediatric sample of patients to assess how the LMAS is being utilized. In this retrospective audit, we evaluated the use of the LMAS in routine clinical practice. In addition to this, utilization of LMAS performance test was evaluated.Methods: A retrospective audit was performed of a major tertiary children's hospital's electronic medical record database to identify all children in whom the LMAS was utilized for airway management over a two-year period. In addition to demographic data, we collected the following LMAS data: size of the LMAS, the number of insertion attempts, volume of air injected into the cuff, the cuff pressure, and the oropharyngeal leak pressure. We also recorded the performance of tests for proper position and function, the mode of lung ventilation, the use of muscle relaxants and use of any alternative airway devices.Results: The LMAS was used in 418 children accounting for only 4% of all LMA usage and only 0.6% of all usage for general anesthesia. The first-attempt placement success rate was 96.4% (382/396). Five of 418 (1.2%) insertions were reported as failures. Mechanical ventilation was used in only 26% of cases with a vast majority (74%) breathing spontaneously. Cuff pressure was measured in 74/418 (18%) of cases. Oropharyngeal leak pressures were measured in 90/418 (21.5%) cases. Maneuvers performed to verify correct placement and performance of the LMAS were rarely performed. Use of the LMAS for invasive procedures occurred in only 5 cases (1.2%).Conclusions: This study shows the LMAS to be highly successful in the hands of various cadres of anesthesia providers at a major tertiary hospital and performs reliably well. Our data reveals many areas of potential improvement for use of the LMAS in the pediatric population, as a device capable for usage in more invasive surgical procedures, younger patients, and mechanical ventilation. Citation: Nobuyuki-Hai Tran, Patrick N. Olomu, Ashley Bocanegra, Asif Khan, John Cheyney, Alexandra Handy, et al. Laryngeal mask airway Supreme in children: a retrospective audit. J Anesth Perioper Med 2016; 3: 241-6. doi: 10.24015/JAPM.2016.0033This is an open-access article, published by Evidence Based Communications (EBC). This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium or format for any lawful purpose. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Keep pushing! Limiting interruptions to CPR; bag-valve mask versus i-gel® airway ventilation

Background: Recent recommendations made by ILCOR have de-emphasised the role of advanced airway management such as “endotracheal intubation” (ETI) during cardiac arrest in favour of maximising the number of chest compressions performed by rescuers. Maximising time available for compressions is achieved by minimising hands-off time (HOT). This has led to first responders and paramedics performing single rescuer CPR using a bag-valve-mask (BVM) device as opposed to the historical practice of intubating and ventilating via an endotracheal tube. Bag-valve-mask ventilations, especially during single rescuer CPR, are however associated with complications potentially resulting in increased ventilation times. More time spent on ventilations in the single rescuer scenario naturally leads to an increase in HOT and less time being available for compressions. It is postulated that the use of an appropriate supraglottic airway device (SAD) may decrease the time spent on the ventilation component of CPR and result in a decrease in HOT.Objectives: This pilot study evaluated how interruptions to chest compressions or hands-off time (HOT) are affected by the placement of an i-gel® airway vs. simple BVM ventilation during single rescuer CPR.Method: 16 participants performed two, ten-minute single rescuer CPR simulations, firstly using the BVM and later the i-gel® airway for ventilation. Data pertaining to ventilations and HOT in each scenario was statistically analysed and compared.Results: The i-gel® airway demonstrated a superior ease of ventilation compared to BVM alone and resulted in a reduction of time spent on ventilations overall. The i-gel® however took a mean of 29 s, ± 10 s, to secure which contributes considerably to HOT.Conclusion: The use of the i-gel® airway resulted in a considerable decrease in the amount of time spent on ventilations and in more compressions being performed. The overall reduction in HOT was, however, offset by the time it took to secure the device. Further investigation into the use and securing of the i-gel® airway in single rescuer CPR is recommended.

Design and implementation of the AIRWAYS-2 trial: A multi-centre cluster randomised controlled trial of the clinical and cost effectiveness of the i-gel supraglottic airway device versus tracheal intubation in the initial airway management of out of hospital cardiac arrest

Health outcomes after out of hospital cardiac arrest (OHCA) are extremely poor, with only 7–9% of patients in the United Kingdom (UK) surviving to hospital discharge. Currently emergency medical services (EMS) use either tracheal intubation or newer supraglottic airway devices (SGAs) to provide advanced airway management during OHCA. Equipoise between the two techniques has led to calls for a well-designed randomised controlled trial.The primary objective of the AIRWAYS-2 trial is to assess whether the clinical effectiveness of the i-gel, a second-generation SGA, is superior to tracheal intubation in the initial airway management of OHCA patients in the UK. Paramedics recruited to the AIRWAYS-2 trial are randomised to use either tracheal intubation or i-gel as their first advanced airway intervention. Adults who have had a non-traumatic OHCA and are attended by an AIRWAYS-2 paramedic are retrospectively assessed against eligibility criteria for inclusion.The primary outcome is the modified Rankin Scale score at hospital discharge. Secondary objectives are to: (i) estimate differences between groups in outcome measures relating to airway management, hospital stay and recovery at 3 and 6 months; (ii) estimate the cost effectiveness of the i-gel compared to tracheal intubation. Because OHCA patient needs immediate treatment there are several unusual features and challenges to the design and implementation of this trial; these include level of randomisation, the automatic enrolment model, enrolment of patients that lack capacity and minimisation of bias.Patient enrolment began in June 2015. The trial will enrol 9070 patients over two years. The results are expected to influence future resuscitation guidelines.Trial Registration ISRCTN: 08256118.

LMA Supreme™ and Ambu® AuraGain™ in anesthetized adult patients: a prospective observational study

Second-generation laryngeal masks with gastric access are increasingly used in daily practice and expand the indications for laryngeal masks in the OR. Only limited data exist comparing different types of laryngeal masks. We investigated the second-generation laryngeal masks LMA Supreme™ and Ambu® AuraGain™ in a clinical setting. We hypothesized that the two devices would be comparable in terms of success rate and airway complications. After approval from the local ethics committee, data were collected in a prospective trial. Endpoints were success rate, time to insertion and airway morbidity. Anesthesiologists used either the Supreme (Teleflex Medical GmbH) or Gain (Ambu GmbH) laryngeal mask. Patients <18 years and those with a possible risk of regurgitation were excluded. Data from 351 adult patients were documented (Supreme N.=177; Gain N.=174). Success rate for first attempt was 80% (Supreme) and 72% (Gain; P=0.08). Overall success rate was 89% and 92%, respectively (P=0.38). Providers with minimal experience were more successful at first attempt using Supreme (95%), compared to Gain (67%; P=0.01). The median insertion time was shorter in Supreme at 18 s [interquartile range (IQR), 14-25 s] compared to 30 s for Gain [18-41s] (P<0.0001). A higher incidence of airway complications was observed after device removal for Gain (P=0.009). Supreme was superior to Gain in terms of insertion time and airway morbidity. Novices were more successful at first attempt using Supreme. These differences between supraglottic airway devices might be due to the different shapes and materials of the masks.

Comparison of I-Gel and classic Laryngeal Mask Airway in paediatric population: a parallel group study

Background: I-gel, the novel Supraglottic airway device, is easier to insert, has improved stability after insertion with reduced tissue compression.The study aims to compare the efficacy of I-gel with classic Laryngeal Mask Airway in the paediatric population.Methods: A randomised parallel group study was done in Department of Anesthesiology, Kanti Children Hospital, Kathmandu for a period of three months. I gel and classic LMA was compared based on leak airway pressure, time of insertion and ease of insertion.Results: Age and weight are comparable among groups. Compared to cLMA, I-gel provides a better leak pressure seal (16.40+-3.42 vs. 23.11+- 6.17 cm of H2O, p 0.027), faster time of insertion (19.42+-4.40 vs. 29.84+-7.70 seconds, p-0.02) and similar ease of insertion (p-0.571).Conclusions: I-gel compared to classic Laryngeal Mask Airway provides better resistance to leak airway pressure, faster time of insertion with comparable ease of insertion.

A proposal for a new scoring system to predict difficult ventilation through a supraglottic airway

BackgroundThe aim of this study was to propose and validate a new clinical score to predict difficult ventilation through a supraglottic airway device. MethodsThe score was proposed from our previously reported derivation data, and we prospectively validated the score in 5532 patients from November 2013 to April 2014. Predictive accuracy of the score was compared by the area under the receiver operating characteristic (ROC) curve (AUC). We assigned point values to each of the identified four risk factors: male, age >45 yr, short thyromental distance, and limited neck movement, their sum composing the score. The score ranged between 0 and 7 points. The optimal predictive level of the score was determined using ROC curve analysis. ResultsThe AUC of the score was 0.75 (95% CI 0.66 to 0.84) in the validation data set, and was similar to that in the derivation data set (0.80; 95% CI 0.75 to 0.86). In derivation and validation data sets, the incidence of low risk categories (scores 0–3) was 0.42% vs 0.32% and of high risk categories (scores 4–7) was 3% vs 1.7% respectively. A score 4 or greater is associated with a six to seven fold increased risk of difficult ventilation through a supraglottic airway device. ConclusionsThe new score for prediction of difficult ventilation through a supraglottic airway device is easy to perform and reliable, and could help anaesthetists plan for difficult airway management.

A comparative study between i-gel and classical laryngeal mask airway in elective surgery under general anaesthesia

&lt;p class="abstract"&gt;&lt;strong&gt;Background:&lt;/strong&gt; Supraglottic airway devices have been widely used as an alternative to tracheal intubation during general anesthesia both in adults and children. This study was carried out to compare classical laryngeal mask airway (LMA) and i-gel, regarding ease of insertion, adequate placement of device, ability to maintain ETCO&lt;sub&gt;2&lt;/sub&gt; and SPO&lt;sub&gt;2&lt;/sub&gt;, perioperative hemodynamic parameters and intra operative and postoperative complication.&lt;/p&gt;&lt;p class="abstract"&gt;&lt;strong&gt;Methods:&lt;/strong&gt; This prospective, randomized clinical study was done on 100 patients of either sex, age between 5 to 60 years, ASA grade I-III who underwent different surgical procedures under general anesthesia in supine position. After giving premedication, induction of anesthesia was done with inj. Propofol 2-3 mg/kg and inj. Succnylcoline 1.5-2 mg/kg. In “sniffing air” position, airway was secured with either LMA or i-gel. An effective placement of device was checked by a square wave capnography, normal chest expansion, SPO&lt;sub&gt;2&lt;/sub&gt; &amp;gt;95%, and absence of audible leak. Patients were observed for time and ease of insertion, number of attempts, perioperative hemodynamic changes and complications.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt; No statistically significant difference was reported between both the groups, regarding heart rate, BP, SPO&lt;sub&gt;2&lt;/sub&gt; and ETCO&lt;sub&gt;2&lt;/sub&gt;. Duration of insertion was more in group LMA. Insertion was easy and was possible in first attempt in 88% of patients without much manipulation in group i-gel.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt; I-gel is a better alternative supraglottic airway device than LMA in view of ease of insertion with minimal manipulations and minimal complications. Hemodynamic parameters, SPO&lt;sub&gt;2&lt;/sub&gt; and ETCO&lt;sub&gt;2 &lt;/sub&gt;were maintained in both the groups. &lt;/p&gt;