Fiberoptic View Research Articles

A new video laryngoscope combined with flexible laryngeal mask insertion: A prospective randomized study

BackgroundThe video laryngoscope (VLS) has been proven to be an effective insertion device for airway management. However, no laryngoscope has been specifically designed for the placement of the laryngeal mask airway (LMA). We improved the current VLS and developed a novel VLS method. This study aimed to evaluate the clinical efficacy of an improved VLS for inserting a flexible laryngeal mask airway (F-LMA) compared with the standard blind method. MethodsOne hundred and fifty-seven patients who underwent F-LMA insertion under general anesthesia were randomly assigned to either the standard blind insertion technique (group B) or VLS -assisted insertion (group VL). First attempt success rates were recorded. Secondary outcomes included oropharyngeal leakage pressure (OLP), fiberoptic view, insertion time, position adjustment, reinsertion rate, and postoperative airway morbidity. ResultsThe first-attempt success rate was higher in group VL than that in group B (99% vs. 86%; p = 0.002). The OLP was significantly higher in the VLS-guided technique (26.4 ± 5.1 vs 23.8 ± 4.4 cmH2O, p = 0.002). The fiberoptic view was significantly better in the group VL (p < 0.001) and required less readjustment and reinsertion to establish an effective airway (p < 0.001). The insertion time was shorter in the group B than that in group VL (33.9 vs 41.3 s, p < 0.001). Hemodynamic stress responses and postoperative airway complications did not differ between the two groups. ConclusionsThe new VLS-guided insertion technology has a high success rate, achieves greater OLP, and provides an ideal anatomical position with minimal adjustment, without increasing the risk of hemodynamic stress or adverse events. Trial registrationChinese Clinical Trial Registry (registration number: ChiCTR2300075866; https://www.chictr.org.cn).

To Evaluate the Impact of Pneumoperitoneum on Oropharyngeal Seal Pressure of Proseal™ LMA and Baska™ mask in Patients Undergoing Laparoscopic Cholecystectomy: A Randomized Controlled Trial

Abstract Background: Newer supraglottic airway devices (SGADs) are becoming more and more popular as a means of maintaining the airway during laparoscopic procedures. The present study’s aim was to compare the impact of pneumoperitoneum on the oropharyngeal seal pressure (OPSP) of Proseal™ laryngeal mask airway (PLMA) and Baska™ Mask (BM) in patients undergoing laparoscopic cholecystectomy. Methods: We enrolled 60 American Society of Anesthesiologists physical Status I and II patients and randomised to either the PLMA group or the BM group. After induction of anaesthesia using a standardised protocol, one of the SGADs was inserted. The primary outcome was the effect of pneumoperitoneum on the OPSP of the two devices. The secondary outcomes were the time required for insertion of the airway devices, OPSP, fibre-optic view of the vocal cord, ease of insertion and any laryngopharyngeal morbidity. Results: The demographic parameters were comparable between the study groups. The insertion time was 18.034 ± 7.73 and 18.7 ± 6.96 s for the PLMA group and BM group, respectively (P = 0.7255). The OPSP in each group was not significantly impacted by pneumoperitoneum, although it remained the same throughout the procedure. Compared to the PLMA group, OPSP was higher in the BM group at all three time intervals (5 min after the insertion of the device [T1], 10 min after pneumoperitoneum [T2] and 5 min after the revoking of pneumoperitoneum [T3]). Conclusion: Pneumoperitoneum had no effect on OPSP in either group. Significantly higher OPSP was noted in the BM group (both before and following pneumoperitoneum) compared to the PLMA group.

Comparative evaluation of blind supraglottic airway device insertion versus videolaryngoscope-guided technique in adults undergoing laparoscopic cholecystectomy

ABSTRACT Objectives A videolaryngoscope may decrease the high incidence of aberrant positioning of supraglottic airway devices (SAD) inserted with blind techniques. We aimed to compare Igel insertion characteristics between blind and videolaryngoscope-assisted techniques. Methods In this study 70 adult patients scheduled for elective laparoscopic cholecystectomy under general anesthesia were randomly divided into blind (Group B, n = 35) and videolaryngoscope-guided (Group V, n = 35) Igel insertion. Oropharyngeal leak pressure (OLP), fiber-optic view score, time for device insertion, first attempt success, ease of insertion, ventilation score, maneuvers, and adverse events were assessed. Results OLP was significantly higher in group V at 1 and 10 minutes (24.80 ± 1.91 vs 21.71 ± 2.37; p < 0.001 and 32.60 ± 2.32 vs 30.68 ± 2.93; p = 0.006). The mean fiberoptic scoring (3.63 ± 0.49 vs 3.38 ± 0.49; p = 0.043), a fibreoptic score of grade 4 (24 vs 13; p = 0.012) and time-to-device insertion (25.6 ± 3.5 vs 21.7 ± 4.1; p < 0.001) was considerably higher in group V. First-attempt success (p = 0.630), ease of insertion of SAD (p = 0.540) and nasogastric tube (p = 1), ventilation score (p = 1), number of maneuvers required (p = 1), number of attempts (p = 0.592) and postoperative complications (p = 0.800) were comparable in the two groups. Conclusion The videolaryngoscope-guided technique provided superior airway sealing and reduced malposition of Igel without an increase in adverse events compared to the blind technique. However, this was at the cost of increased time of device insertion. Clinical trial registration www.ctri.nic.in identifier is CTRI/2022/10/046269

Comparative evaluation of self-pressurized Air-Q® and Proseal™ LMA® in patients undergoing elective surgery under general anaesthesia: A randomized clinical trial.

Intra-cuff pressure of Air-Q self-pressurized laryngeal airways (Air-Q SP) balances airway pressure and adapts to patient's pharyngeal and periglottic structures, thus improves oropharyngeal leak pressure (OLP).This study was performed to compare efficacy of Air-Q SP with Proseal laryngeal mask airway (PLMA) in patients undergoing elective surgery. The study design was prospective, randomized and controlled. Ninety patients were randomly assigned to Air-Q SP or PLMA group. All patients were premedicated and shifted to operation theatre. Monitoring was instituted. After securing IV-line, induction with inj. Morphine + Propofol, relaxation with inj. Vecuronium was done. Supraglottic was inserted according to group allocation. Outcome measures were OLP, fibreoptic view of larynx, success rate, device insertion parameters, haemodynamic and respiratory parameters and post-operative laryngopharyngeal complications. Neostigmine + glycopyrrolate were given, device was extubated. All supraglottic airway devices (SADs) were successfully placed in two attempts. The mean initial OLP, OLP at 10 minutes, and device insertion time were significantly lower in Air-Q SP group. Fiber-optic laryngeal view grading was significantly better with Air-Q SP. No significant difference was observed with respect to rate of successful insertion in first attempt, ease of insertion, and manipulations required. The hemodynamic/respiratory parameters and post-operative sore throat in the two both groups were similar. Proseal LMA has a higher OLP than Air-Q SP but average insertion time was better, and fiber-optic grading of laryngeal view was shorter with Air-Q SP. However, Air-Q SP and Proseal LMA were both effective for lung ventilation.

Comparison of oropharyngeal leak pressure of LMA Protector and LMA ProSeal in anaesthetised paralysed patients - A randomised controlled trial.

In the present study, we hypothesised that the laryngeal mask airway (LMA) Protector would provide higher oropharyngeal leak pressure (OLP) than LMA ProSeal. Thus, we planned this study to compare the clinical performance of LMA Protector and LMA ProSeal in terms of OLP as a primary objective and insertion characteristics as secondary objectives. Ninety patients of either gender, aged 18-70 years, were randomised into groups PS (LMA ProSeal) and P (LMA Protector). Following anaesthetic induction, the device was inserted as per group allocation. OLP of both devices was taken as a primary objective. Secondary objectives such as insertion time, ease of insertion, number of attempts required, fibre-optic view grading, amount of air (mL) required to get a cuff pressure (CP) of 60 cm H2O, and CP adjustment required and complications, if any, were also noted. Data were analysed using coGuide statistics software, Version 1 (BDSS Corp. Bangalore, Karnataka, India). The median (interquartile range) OLP was significantly higher with LMA protector than with LMA ProSeal [33.00 (27.0, 36.0) versus [29.50 (26.0, 32.0) (P = 0.009)]. First-attempt success rate was 95.4% (42/44) in group PS and 93% (40/43) in group P. Insertion time, ease of insertion, and fibre-optic view grading were not different between the groups. Gastric tube placement failed in one patient in group PS and in three patients in group P (P = 0.606). The median amount of air (mL) required to get a CP of 60 cm H2O was 26.5 (20, 28) in group PS and 12 (8,13) in group P (95% confidence interval [CI] =10.808-14.575) (P < 0.001). At all time points, CP was significantly higher, and more CP adjustments were needed in group PS than in group P (P < 0.001). Incidence of blood staining and post-operative sore throat at 1 and 24 h were not different between the groups. LMA Protector provided a significantly higher OLP and less requirement of CP adjustments but comparable first-attempt success rate, mean insertion time, fibre-optic view, and gastric tube insertion as compared to LMA ProSeal.

Comparison of clinical performance of Baska mask and Ambu AuraGain in patients undergoing surgery: A single-blinded, randomised comparative trial.

The Baska mask (BM) and the Ambu AuraGain (AAG) have shown promising results in recent trials but have not been compared. Therefore, we aimed to compare the clinical performance of the BM and the AAG for airway management of adult patients. In this randomised comparative study, patients aged 18-60 years and with an expected surgical duration of less than 2 h were enroled. Patients were randomly allocated to AAG (Group A, n = 37) and BM (Group B, n = 37) for airway management. After induction of anaesthesia, an allocated supraglottic airway device (SAD) was inserted. Oropharyngeal leak pressure (OLP), time taken to insert SAD, number of insertion attempts, leak fraction (LF), first-attempt success rate, overall success rate, ease of insertion, fiberoptic view of the glottis, and complications were compared. The data were analysed using Student's t-test, Mann-Whitney U test, and Fisher's exact tests. Baseline and demographic characteristics were comparable. OLP (31.32 ± 2.59 versus 27.54 ± 1.32 cmH2O) was higher (P < 0.001), and LF (6.19% ± 1.20% versus 7.24% ± 1.72%) was lower (P = 0.003) in the BM group. First-attempt and overall success rate, time taken to insert, number of insertion attempts, ease of insertion, and fibreoptic view of glottis through the SADs were statistically similar between groups. However, the incidence of sore throat (P = 0.007) and cough (P = 0.028) was higher with AAG. Clinical performance of BM was better than AAG as the former had higher OLP, lower LF and complications.

I-gel Plus acts as a superior conduit for fiberoptic intubation than standard i-gel

The supraglottic airway (SGA) is widely used. I-gel Plus is a next-generation i-gel with some improvements, including facilitation of fiberoptic tracheal intubation (FOI). To compare the performance of i-gel Plus and standard i-gel as conduits for FOI, a Thiel-embalmed cadaveric study was conducted. Twenty-two anesthesiologists were enrolled as operators in Experiment 1. The i-gel Plus and standard i-gel were inserted into one cadaver, and the FOI was performed through each SGA. The primary outcome was time required for FOI. The secondary outcomes were the number of attempts and visual analog scale (VAS) score for difficulty in FOI. Moreover, fiberoptic views of the vocal cords in each SGA were assessed by an attending anesthesiologist using nine cadavers in Experiment 2. The percentage of glottic opening (POGO) score without fiberscope tip upward flexion and upward angle of the fiberscope tip to obtain a 100% POGO score were evaluated as secondary outcomes. The time for FOI through i-gel Plus was significantly shorter than that through standard i-gel (median (IQR), i-gel Plus: 30.3 (25.4–39.0) s, vs standard i-gel: 54.7 (29.6–135.0) s; median of differences, 24.4 s; adjusted 95% confidence interval, 3.0–105.7; adjusted P = 0.040). Although the number of attempts for successful FOI was not significantly different, the VAS score for difficulty in the i-gel Plus group was significantly lower (easier) than that in the standard i-gel group. Moreover, i-gel Plus required a significantly smaller upward angle of the fiberscope tip to obtain a 100% POGO score. FOI can be performed more easily using i-gel Plus than using standard i-gel because of the improved fiberoptic visibility of vocal cords.

Comparison of insertion characteristics of LMA ProSeal from the front and head-end of the patient: A randomized pilot study.

LMA ProSeal (PLMA) is a commonly used airway maintenance device in elective procedures and is routinely inserted from the head-end of the patient. It is also used in pre-hospital emergencies where it may not always be possible to access the head-end. This study aims to compare the insertion characteristics of PLMA when inserted while standing, either at the head-end or from the front. After institutional ethics committee approval, 60 consenting patients of either sex, between 18 and 60 years, ASA class I/II, and scheduled to undergo elective surgeries were randomly allocated to either group H (head-end insertion) or group F (front-end insertion). Patients with anticipated difficult airway, chronic respiratory disease, obesity, and who were pregnant were excluded. Insertion time, ease of insertion, fiber optic view, ease of drain tube insertion, number of attempts and success rate were noted. Normally distributed quantitative variables were compared using t-test, and qualitative variables were compared using Chi-squared test. A P < 0.05 was considered significant. Insertion time in group H (23.76 ± 4.48 s) was lesser than in group F (30.53 ± 6.23s) (P = 0.027). Ease of insertion (P = 0.052), fiber optic view, ease of drain tube placement (P = 1.000), and number of attempts (P = 1.000) were comparable among the groups. Although the insertion time from the front is longer than from the head-end, the other insertion characteristics of PLMA including ease of its insertion, placement and success rate of placement are similar when it is inserted from the front or from the head-end. It is an appropriate airway device for securing the airway when the head-end is inaccessible.

Randomized Clinical Trial Comparing the Success Rate of Blockbuster Intubating Laryngeal Mask Airway Versus Fastrach Intubating Laryngeal Mask Airway During Blind Endotracheal Intubation.

Background A new piece of equipment, the Blockbuster (BB) Intubating Laryngeal Mask Airway (ILMA; Tuoren MedicalIndia, Gurugram, India), was created in 2012. Dr. Chandy created the Fastrach (F) ILMA in 1997, which is another supraglottic airway equipment. The primary purpose of this study was to compare the success rateof intubation with BB-ILMA and F-ILMA. Methods In the chosen age category of >20 to <70 years, undergoing general anesthesia for intubation with ILMAs, 55 patients were in the BB-ILMA(group B), and 55 patients were in the F-ILMA (group F). These ILMAs were put in after the induction and checked to see if adequate ventilation was accomplished with either of these devices. Once ventilation had been attained, weproceeded with fiberoptic scope to visualize the glottis, followed by blind intubation. The primary objective was to compare the first pass successful intubation of BB-ILMA and F-ILMA. The secondary objectives were ease of LMA insertion, time taken for intubation, hemodynamic changes, glottis fiberoptic view, and complications. Results The first pass successful intubation of the BB-ILMA and F-ILMA are 94.5% and87.3%, respectively, whereas thetime taken for intubation in BB-ILMA and F-ILMA are 25.02 seconds (s) and42.77 s with ap-value of 0.0001, indicating a statistically significant relationship. Conclusion When compared to the F-ILMA (group F), the BB-ILMA (group B) has a higher success rate for blind tracheal intubation, with lesser time taken for intubation and fewer complications.

A randomized controlled study to compare oropharyngeal leak pressure between I-gel™ and laryngeal mask airway supreme™ in children in lateral position under general anesthesia

BackgroundSupraglottic airway devices (SADs) are the mainstay for airway management in pediatric ambulatory surgeries and may often be a suitable alternative to endotracheal intubation due to their favorable profile. Optimal oropharyngeal leak pressure of SAD is essential for adequate ventilation and prevention of aspiration. Occasionally, lateral position is required for administration of regional block or for the surgery itself.We aim to compare the oropharyngeal leak pressure of igel™ and LMA Supreme™ in children in lateral position.A prospective, randomized study was performed on eighty children of either sex, weighing 5–10 kg, belonging to ASA grade I and II undergoing elective surgery requiring lateral position. The primary objective was comparison of Oropharyngeal leak pressure of both devices in lateral position. Secondary objectives included assessment of insertion success rate, number of insertion attempts and manipulations, time and ease of insertion; and comparison of fiberoptic view of the larynx, fractional volume loss, and displacement with respect to both devices in supine and lateral position.ResultsOropharyngeal leak pressure of i-gel™ was higher than that of LMA Supreme™ in both supine (25.4 ± 1.4 cm H2O Vs 22.9 ± 1.5 cm H2O) and lateral position (23.9 ± 1.6 vs 21.5 ± 1.5 cm H2O) and was statistically significant (p < 0.001). The success rate of insertion of i-gel™ and LMA Supreme™ was similar (95% and 97.5% respectively). The ease of insertion for both devices was statistically similar (p = 0.593). The mean time for insertion was longer for i-gel™ (15.4 ± 1.72 s vs 12.4 ± 1.73 s) as compared to LMA Supreme™ (p < 0.001). Ventilatory parameters for both devices decreased in the lateral position, which was statistically significant. The fractional volume loss after change of position was 0.123 vs 0.478 for i-gel™ and LMA Supreme™ respectively. In both groups, fiberoptic views worsened with a change of position.ConclusionsOropharyngeal leak pressure of both devices reduced in lateral position as compared to supine position. I-gel™ yielded higher leak pressures in supine as well as in lateral position as compared to LMA Supreme™.ImplicationsThe above findings offer valuable insight for decision-making in pediatric daycare surgeries requiring lateral position where GA is warranted.Trial registrationCTRI NUMBER (CTRI/2021/01/030442)—the trial was registered with the Clinical Trial Registry of India on 13 January 2021.

LMA Protector ve Baska Maskın Retrograd Üreteroskopik Cerrahide Karşılaştırılması: Prospektif Randomize Klinik Çalışma

Objective: The Baska and the Protector Laryngeal masks are single-use second-generation supraglottic airway devices with a dual gastric channel. Material and Methods: 64 American Society of Anesthesiologists physical status 1-2 patients between the ages of 18-70 undergoing retrograde ureteroscopic surgery enrolled in this prospective randomized study. Results: Demographic airway variables and airway characteristics were similar between the groups. Insertion time was shorter in the Baska mask group [14 (11-20) versus 20 (13-27) seconds, p=0.035]. The need for optimization maneuvers during insertion was higher for the Baska mask group (p=0.009). The laryngeal mask airway (LMA) insertion was easier in the LMA Protector group (p=0.023). The first insertion success rate was 75% for the LMA Protector and 84% in the Baska mask. The total success rate of both devices was 91%. Nasogastric tube insertion was faster in the Baska mask group [14 (12-15) versus 17 (13-25) seconds; p=0.003]. Fiberoptic views were similar between the groups. Minute volume after insertion of the device was higher in the LMA Protector group [8 (6.5-10) L/min versus 6 (5-7) L/min; p<0.001]. Expiratory tidal volume was higher in the LMA Protector group after insertion of the device, 15 minutes, 30 minutes, and 45 minutes after insertion (p<0.001, p=0.032, p=0.001, p=0.027 respectively). The end-tidal sevoflurane concentration (ETsevo) 30 minutes after device insertion was higher in the Baska mask group (1.49±0.38 vs 1.75±0.36; p=0.014). Conclusion: The LMA Protector is superior to the Baska mask in providing higher tidal volumes and decreased need for optimization maneuvers in retrograde ureteroscopic surgery.

Comparison of Laryngeal tube suction II (LTS II) and Proseal laryngeal mask airway (PLMA) for controlled ventilation in anaesthetised and paralysed adult patients

Background: LTS II and PLMA are supraglottic devices that may be used for ventilation in patients with normal as well as difficult airways at risk of aspiration. Aim: Comparison of LTS II with PLMA during controlled ventilation in paralysed patients with respect to time to successful insertion, success rate of insertion, attempts at repositioning, airway leak pressure, ease of ventilation and Ryle’s tube insertion, fibreoptic laryngeal view and complications. Methods: Thirty patients were studied using a prospective, randomised cross-over design. Ethical committee clearance and informed consent were obtained from all patients. Anaesthesia was induced with propofol and fentanyl and neuromuscular blockade achieved with vecuronium. Patients were divided into two groups: Group LTS and Group PLMA. In each group, the first airway device was inserted, various parameters observed and then removed. The second airway device was then inserted and the same parameters noted. Anaesthesia was continued with the second device in position. Results: Success with insertion at first attempt and time to insertion were comparable with both devices [LTS II 27/30 (17.5 s) and PLMA 29/30 (15.5 s) respectively]. PLMA required repositioning in fewer patients and provided better fibreoptic view than LTS II. Ryle’s tube insertion failed in four patients with PLMA but in none with LTS II. No significant difference was found in the airway seal pressure [mean, PLMA (27 cm H2 O) and LTS II (26.4 cm H2 O)], ease of ventilation or overall complications. Conclusion: Insertion and ventilation are comparable with PLMA and LTS II. Ryle’s tube insertion is easier with LTS II but requires more repositioning attempts and does not provide a good view of the larynx

Comparison of the supraglottic airway device BlockBusterTM and laryngeal mask airway Supreme in anaesthetised, paralyzed adult patients: a multicenter randomized controlled trial

ABSTRACT Background This multicenter prospective, randomized controlled clinical trial compared the clinical performance of supraglottic airway device (SAD) BlockBusterTM and laryngeal mask airway (LMA) Supreme for airway maintenance in anesthetized, paralyzed adult patients. Methods A total of 651 adult patients scheduled for elective surgery in 13 hospitals were randomly allocated into BlockBuster group (n = 351) or Supreme group (n = 300). The primary outcome was oropharyngeal leak pressure (OLP). Duration and ease of insertion, fiberscopic view of positioning, airway manipulations, and complications were also assessed. Results The OLP was significantly higher in BlockBuster group compared with Supreme group (29.9 ± 4.2 cmH2O vs 27.4 ± 4.3 cmH2O, p < 0.001). Success rate of insertion at the first attempt (90.2% vs 85.1%, p = 0.027), rate of optimal fiberscopic view (p = 0.002) and satisfactory positioning of SAD (p < 0.001) were significantly increased in BlockBuster group. Conclusions Both SAD BlockBusterTM and LMA Supreme are safe, effective, and easy-to-use devices for airway maintenance in anesthetized, paralyzed adult patients, but the SAD BlockBusterTM is superior to LMA Supreme in terms of OLP, success rate at the first attempt, and fiber-optic view of positioning. Trial registration The trial is registered at www.chictr.org.cn (ChiCTR-ONC-16009105).

Comparison of the third-generation streamlined liner of the pharynx airway (SLIPA-3G) with the laryngeal mask airway supreme for laparoscopic cholecystectomy: a randomized prospective study

BackgroundThe third-generation streamlined liner of the pharynx airway (SLIPA-3G) is a new-generation supraglottic airway device (SAD) that is non-cuffed and disposable, with a sealing pressure that varies dynamically with the airway pressure. This study compared the SLIPA-3G with the laryngeal mask airway supreme (LMAS) in patients undergoing laparoscopic cholecystectomy.MethodsTwo hundred and twenty patients scheduled for laparoscopic cholecystectomy were randomly allocated to either the SLIPA-3G group or the LMAS group. Data were collected on the patients’ hemodynamic parameters at different time points, ease of insertion, fiberoptic view, oropharyngeal leak pressure (OLP) at different time points and SAD-related complications.ResultsThe mean OLP immediately after device placement in the LMAS group was significantly higher than that of the SLIPA-3G group (31.34 ± 6.99 cmH2O vs.28.94 ± 6.01 cmH2O, P = 0.008, 95% CI 0.62–4.17). The OLPs of the two groups were not significantly different after the induction of a pneumoperitoneum until the end of surgery. The OLP increased gradually through the course of the operation in the SLIPA-3G group (P value = 0.035) but not in the LMAS group (P value = 0.945). There was no significant difference between the two groups in hemodynamic parameters, insertion time and success rate, fiberoptic view and complication rate.ConclusionsThe SLIPA-3G and LMAS were associated with comparable OLPs, hemodynamic parameters, ease of insertion, fiberoptic views and complication rates when used during laparoscopic cholecystectomy. The SLIPA-3G can be used as an effective alternative to the LMAS in patients undergoing laparoscopic surgeries.

Comparison of the oropharyngeal leak pressure between three second generation supraglottic airway devices during laparoscopic surgery in pediatric patients.

Previous studies have shown Proseal LMA and I gel similar to endotracheal intubation in ventilatory ability in pediatric laparoscopic surgeries. The primary aim of this study was to assess whether there is a significant difference in the oropharyngeal leak pressure between Ambu Auragrain, I-gel, and Proseal LMA during pediatric laparoscopic surgery. In this randomized controlled trial, 90 male patients of American Society of Anesthesiologists physical status I aged between 6 months and 10 years who were scheduled for laparoscopic single-sided inguinal hernia repair were recruited and randomly allocated to three groups in which airway was secured with Ambu Auragain, I gel, or Proseal LMA. The primary outcome was oropharyngeal leak pressure. The secondary outcomes were peak pressures before and after pneumoperitoneum, fiberoptic view, insertion attempts, insertion time, manipulations, perioperative and postoperative anesthesia-related problems. Continuous variables were compared using the one-way analysis of variance or the Kruskal-Wallis test with post hoc Turkey analysis. Categorical and ordinal data were compared using the chi-square test or Fisher's exact test. Oropharyngeal leak pressure before pneumoperitoneum was higher with I gel as compared to Ambu Auragain (27.36 ± 5.72 cm of H2 O vs 23.56 ± 5.72 cm of H2 O) (p = .021) and PLMA (27.36 ± 5.72 cm of H2 O vs 23.24 ± 4.35 cm of H2 O) (p = .011). Oropharyngeal leak pressure after pneumoperitoneum was also higher with I gel as compared to Ambu Auragain (31.58 ± 4.35 cm of H2 O vs 26.83 ± 5.00 cm of H2 O) (p = .001) and Proseal LMA (31.58 ± 4.35 cm of H2 O vs 27.03 ± 3.80 cm of H2 O) (p = .002). Oropharyngeal leak pressures of Ambu Auragain and Proseal LMA were comparable. Postoperative complications were similar in all the supraglottic airway devices. No regurgitation or aspiration-related problem was observed in our study. I gel had a higher oropharyngeal leak pressure than the other two supraglottic airway devices and therefore may represent a better choice in situations where higher ventilatory pressures may be necessary, for example, in extremes of weight trendelenburg position, etc. CLINICAL TRIAL IDENTIFIER: Clinical trial registry of India (CTRI/2018/11/016445).

Influence of different head and neck positions on oropharyngeal leak pressures and cuff positions with Ambu® AuraGainTM laryngeal airway in children

Background: Ambu® AuraGain™ laryngeal airway is a supraglottic airway device designed to provide better airway protection and airway seal pressures. Aim of Study: To quantify oropharyngeal leak pressures (OPLPs), fibreoptic view, peak airway pressure and ventilation scoring with Ambu® AuraGain™ in children in different head and neck positions such as maximum flexion, maximum extension and lateral rotation. Patients and Methods: Sixty-eight children aged between 1 and 6 years posted for surgery were enrolled. Ambu® AuraGain™ was inserted after the induction of anaesthesia and ventilation was confirmed. OPLP, fibreoptic view, peak airway pressure and ventilation scores were noted in different head and neck positions such as maximum flexion, maximum extension and lateral rotation. Results: The OPLP significantly increased in flexion (P < 0.001) and significantly decreased in extension (P < 0.001) when compared to the neutral position. Airway pressure (Paw) increased significantly in flexion (P < 0.001) and decreased in extension (P = 0.04) when compared to the neutral position. Tidal volume delivery was comparable in all positions. There was a statistically significant decrease in ventilation scoring in the flexed position when compared to the neutral position (P = 0.005). There was a significant worsening of fibreoptic view in flexion when compared to the neutral position (P < 0.001). Fibreoptic view in the lateral position and extension was comparable with the neutral position. Conclusions: Use of Ambu® AuraGain™ laryngeal airway provides the best ventilatory parameters and Paw in children with head in the neutral and lateral position but lower OPLP with head in extension. However, flexing the head results in the worst ventilatory parameters and Paw among the positions studied.

Effect of diffusion of anaesthetic gases on fibre-optic view change of laryngeal mask airway and post-operative laryngo-pharyngeal morbidity in children - A randomised controlled trial.

Background and Aims:The diffusion of nitrous oxide (N2O) into the air-filled cuff of the classic laryngeal mask airway (LMA) may lead to an increase in cuff pressure (CP) and displacement of LMA affecting its performance. This study was conducted to evaluate the change in optimal position of LMA by fibre-optic bronchoscope, the changes in cuff pressure and oropharyngeal leak pressure (OLP), and post-operative laryngo-pharyngeal morbidity during N2O–oxygen (O2) anaesthesia in children.Methods:After ethics committee approval and written informed consent, 84 children, aged 2 to 8 years undergoing lower abdominal surgery using LMA were included. Anaesthesia was induced with sevoflurane and maintained with either 33% O2 in air (Group 1) or with 33% O2 in 67% N2O (Group 2) along with sevoflurane. The position of LMA using fibre-optic bronchoscope, CP and OLP were recorded at 30, 60 and 90 minutes and at the end of surgery. The incidence of post-operative sore throat, hoarseness of voice and dysphagia was assessed for 24 hours.Results:A mild (Grade 1) change in fibre-optic position of LMA was observed in 6 out of 42 children maintained with N2O–O2 anaesthesia. The cuff pressure was higher than baseline in group 2 at all three time points with the maximum at 90 minutes (93.23 ± 14.86 cm H2O vs. 39.78 ± 7.75 cm H2O; P < 0.05). The OLP was comparable between the groups during the initial 60 minutes and then increased in group 2. The incidence of post-operative sore throat was significantly higher in group 2 (P = 0.008).Conclusion:The diffusion of anaesthetic gases into the air-filled cuff does not change the fibre-optic position of the LMA significantly but increases the cuff pressure and incidence of post-operative laryngo-pharyngeal complications in children.

Comparison of Proseal LMA with i-Gel in children under controlled ventilation: a prospective randomised clinical study

BackgroundSupraglottic airway device is presently the most common modality of airway management in children for short surgical procedures. The i-gel is one such novel supraglottic airway device with a non-inflatable cuff. The objective of the present study was to evaluate the efficiency of i-gel compared to LMA Proseal regarding oropharyngeal leak pressure, insertion time, ease of insertion, and fibreoptic view of larynx. MethodsAfter obtaining ethical clearance and parental consent, 70 children aged 2–10 years, weighing 10–30 kg were randomised to receive LMA Proseal or i-gel for airway management. Data with respect to oropharyngeal leak pressure, insertion time, ease of insertion, number of attempts, and fibreoptic score were collected. The primary outcome was the oropharyngeal leak pressure with the two supraglottic airway devices measured by manometric stability. ResultsDemographic data were comparable between the two groups. The oropharyngeal leak pressure (LMA Proseal vs. i-gel, 20.51 ± 4.71 cmH2O vs. 19.57 ± 5.71 cmH2O), ease of insertion, number of attempts, and fibreoptic view score was similar between the two groups. The insertion time was faster with i-gel (22.63 ± 5.79 s) compared to LMA Proseal (43.26 ± 7.85 s). ConclusionI-gel was similar to LMA Proseal with respect to oropharyngeal leak pressure in children under controlled ventilation.

Comparative evaluation of Air-Q blocker and Proseal laryngeal mask airway in patients undergoing elective surgery under general anaesthesia: A randomised controlled trial.

Background and Aims:The Air-Q blocker (Cook gas LLC, Mercury Medical, Clearwater, FL, USA) is a relatively new supraglottic airway device (SAD) with capability to serve as a conduit for intubation. As there is limited data on Air-Q blocker, the present study was performed to compare the efficacy of Air-Q blocker and Proseal laryngeal mask airway (PLMA) in patients undergoing elective surgery.Methods:A total of 90 American Society of Anesthesiologists (ASA) physical status I and II patients were randomly allocated to Air-Q blocker or PLMA group. Oropharyngeal leak pressure (OLP), insertion success, insertion time, ease of orogastric tube (OGT) insertion, fibreoptic visualisation of the glottis, haemodynamic and ventilation parameters, and complications at emergence and postoperatively were investigated.Results:OLPs were higher in PLMA group as compared to Air-Q blocker group (P = 0.002). Still, the OLP (27.5 ± 5.8 cm H2O) was clinically effective in Air-Q blocker group. The mean time for successful insertion was significantly shorter for Air-Q blocker than PLMA (P = 0.019). The number of attempts to insert both the devices was comparable (P ≥ 0.05). Air-Q blocker provided a significantly better fibreoptic score than PLMA (P = 0.038). The two groups were comparable in terms of ease of OGT insertion, haemodynamics and ventilation parameters, and complications at emergence and postoperatively.Conclusions:Air-Q blocker provides a clinically effective OLP though PLMA provides a slightly better sealing function in patients undergoing laparoscopic and non-laparoscopic surgeries under general anaesthesia requiring neuromuscular blockade. Air-Q blocker has shorter insertion time and a better fibreoptic view of glottis as compared to PLMA.

Comparison between I-gel and Classic Laryngeal Mask Airway for Airway Management of Patients with Anticipated Difficult Airway: A Randomised Clinical Trial

Introduction: I-gel and classic Laryngeal Mask Airway (cLMA) are two Supraglottic Airway Devices (SAD) used for management of airway in various situations, including for management of difficult airway. Despite widespread use of these devices, there are very few trials studying I-gel and classic LMA for management of patients with difficult airway. The outcome of present study determines which SAD is better for managing difficult airway. Aim: To compare I-gel and cLMA in managing anticipated difficult airway. Materials and Methods: This randomised and single blinded clinical trial study was conducted in King George’s Medical University, Lucknow, Uttar Pradesh, India, between February 2019 to January 2020. Adult patients with Mallampati class 3 or 4, thyromental distance &lt;6 cm, sternomental distance &lt;12 cm, restricted neck movement, micrognathia/retrognathia or short/thick neck undergoing elective short duration surgery under general anaesthesia were included in this study. Total 50 patients divided into group C received cLMA while group I patients received I-gel for airway management. Fifty patients were recruited in each group. Nominal variables were analysed using chi-squared test. A two-sided p&lt;0.05 were considered significant for all the tests. Analysis was performed using Statistical Package for Social Sciences (SPSS) version 25.0 for windows. Results: Mean age in group C was 40.38±12.96 (years) and in group I was 37.94±11.77 (years) with p-value 0.327. Overall (n=44 in group C, 50 in group I, p-value=0.012) and first attempt (n=10 in group C, 40 in group I, p-value &lt;0.001) success rate of device placement was higher for I-gel. Number of attempts, manipulations, time needed to insert and Leak Fraction was significantly lower for I-gel (p-value &lt;0.001). Compared to cLMA, Oropharyngeal Leak Pressure (OLP) was higher with I-gel. Fibreoptic view on a four-point scale was better with I-gel. Desaturation, tachycardia, bradycardia, and postoperative sore throat was more frequent with cLMA. Conclusion: Compared to cLMA, I-gel has higher success rate of insertion in patients with difficult airway and has added advantage of more rapid insertion, higher OLP and need for fewer insertion attempts and manipulations with lower rates of complications.