Evaluation of the i-gel® Plus supraglottic airway device in elective surgery: a prospective international multicentre study.

BACKGROUND: The i-gel® Plus is a modified version of the i-gel® supraglottic airway device. It contains a wider drainage port; a longer tip; ramps inside the breathing channel; and an additional port for oxygen delivery. There has been no prospective evaluation of this device in clinical practice. METHODS: This international, multicentre, prospective cohort study aimed to evaluate the performance of the i-gel Plus in adult patients undergoing elective procedures under general anaesthesia. The primary outcome was overall insertion success rate, defined as the ability to provide effective airway management through the device from insertion until the end of the surgical procedure. Secondary outcomes included device performance and incidence of postoperative adverse events. Data from the first 1000 patients are reported. RESULTS: In total, 1012 patients were enrolled; 12 forms were excluded from the final analysis due to incomplete data leaving 1000 included patients (545 female). Overall insertion success rate was 98.6%, with a first-attempt success rate of insertion of 88.2%. A significant difference between females and males was seen for the overall success rate (97.4% vs. 99.6% respectively) but not for first-attempt successful insertion. Mean (SD) oropharyngeal seal pressure was 32 (7) cmH2O. The only independent factor that increased the risk of first-attempt failure was low operator experience. Complications included desaturation < 85% in 0.6%; traces of blood on the device in 7.4%; laryngospasm in 0.5%; and gastric contents inside the bowl in 0.2% of patients. CONCLUSIONS: The i-gel Plus appears to be an effective supraglottic airway device that is associated with a high insertion success rate and a reasonably low incidence of complications.

Comparison of the effects of paratracheal pressure and cricoid pressure on placement of the i-gel® supraglottic airway: a randomized clinical trial.

PURPOSE: Anesthesiologists can use supraglottic airway devices as a rescue technique for failed intubation even in patients with an increased risk of gastric regurgitation. In this randomized study, we aimed to evaluate the effects of cricoid pressure and paratracheal pressure on placement of the i-gel® (Intersurgical Ltd., Wokingham, Berkshire, UK). METHODS: After induction of anesthesia in 76 adult patients, we inserted the i-gel under paratracheal or cricoid pressure, and assessed the success rate of i-gel insertion, resistance during insertion, time required for insertion, accuracy of the insertion location, tidal volumes, and peak inspiratory pressure with or without each maneuver after i-gel insertion. RESULTS: The overall success rate of insertion was significantly higher under paratracheal pressure than under cricoid pressure (36/38 [95%] vs 27/38 [71%], respectively; difference, 24%; 95% confidence interval [CI], 8 to 40; P = 0.006]. Resistance during insertion was significantly lower under paratracheal pressure than under cricoid pressure (P < 0.001). The time required for insertion was significantly shorter under paratracheal pressure than under cricoid pressure (median [interquartile range], 18 [15-23] sec vs 28 [22-38] sec, respectively; difference in medians, -10; 95% CI, -18 to -4; P < 0.001). Fibreoptic examination of the anatomical alignment of the i-gel in the larynx revealed no significant difference in the accuracy of the insertion location between the two maneuvers (P = 0.31). The differences in tidal volume and peak inspiratory pressure with or without the maneuvers were significantly lower with paratracheal pressure than with cricoid pressure (P = 0.003, respectively). CONCLUSIONS: Insertion of the i-gel supraglottic airway was significantly more successful, easier, and faster while applying paratracheal pressure than cricoid pressure. STUDY REGISTRATION: ClinicalTrials.gov (NCT05377346); first submitted 11 May 2022.

RéSUMé: OBJECTIF: Les anesthésiologistes peuvent utiliser des dispositifs supraglottiques comme technique de sauvetage en cas d'échec de l'intubation, même chez les personnes présentant un risque accru de régurgitation gastrique. Dans cette étude randomisée, nous avons cherché à évaluer les effets de la pression cricoïdienne et de la pression paratrachéale sur le positionnement du dispositif i-gel® (Intersurgical Ltd., Wokingham, Berkshire, Royaume-Uni). MéTHODE: Après l'induction de l'anesthésie chez 76 adultes, nous avons inséré l'i-gel en utilisant une pression paratrachéale ou cricoïdienne, et avons évalué le taux de réussite de l'insertion de l'i-gel, la résistance pendant l'insertion, le temps nécessaire à l'insertion, la précision de l'emplacement d'insertion, les volumes courants ainsi que la pression inspiratoire maximale avec ou sans chacune des manœuvres après l'insertion de l'i-gel. RéSULTATS: Le taux global de réussite de l'insertion était significativement plus élevé avec une pression paratrachéale qu'avec une pression cricoïdienne (36/38 [95 %] vs 27/38 [71 %], respectivement; différence, 24 %; intervalle de confiance [IC] à 95 %, 7,6 à 39,8; P = 0,006]. La résistance lors de l'insertion était significativement plus faible en utilisant une pression paratrachéale par rapport à une pression cricoïdienne (P < 0,001). Le temps nécessaire à l'insertion était significativement plus court après avoir exercé une pression paratrachéale plutôt que cricoïdienne (médiane [écart interquartile], 18,4 [15,3­23,1] secondes vs 28,4 [22,3 à 37,8] secondes, respectivement; différence dans les médianes, −10,0; IC 95 %, −18,4 à −3,6; P < 0,001). L'examen par fibre optique de l'alignement anatomique de l'i-gel dans le larynx n'a révélé aucune différence significative dans la précision de l'emplacement d'insertion entre les deux manœuvres (P = 0,31). Les différences de volume courant et de pression inspiratoire maximale avec ou sans les manœuvres étaient significativement plus faibles avec la pression paratrachéale qu'avec la pression cricoïdienne (P = 0,003, respectivement). CONCLUSION: L'insertion du dispositif supraglottique i-gel a été significativement plus réussie, plus facile et plus rapide lors de l'application d'une pression paratrachéale que d'une pression cricoïdienne. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05377346); soumis pour la première fois le 11 mai 2022.

Effective bolus dose of remimazolam for i-gel® insertion in nonparalyzed patients: a dose-finding study.

PURPOSE: Remimazolam is a recently developed ultra-short-acting benzodiazepine used for anesthesia induction and maintenance. Nevertheless, the effective bolus dose of remimazolam for i-gel® (Intersurgical Ltd., Wokingham, Berkshire, UK) insertion without the use of neuromuscular blocking agents (NMBAs) has not been well established. METHODS: This study included 25 adult patients scheduled for surgery under general anesthesia who were eligible for i-gel use. Anesthesia was induced with predetermined bolus doses of remimazolam, starting at 0.3 mg·kg-1 for the first patient, without the use of NMBAs. All patients concurrently received remifentanil using target-controlled infusion (TCI) at a fixed effect-site concentration (Ce) of 3.0 ng·mL-1. Insertion of the i-gel was attempted 90 sec after remimazolam administration, and insertion conditions were assessed. Subsequent doses of remimazolam were decreased or increased by 0.05 mg·kg-1, depending on the success or failure of i-gel insertion. RESULTS: The mean (standard deviation) 50% effective dose (ED50) of a remimazolam bolus for successful i-gel insertion as determined by the modified Dixon's up-and-down method was 0.100 (0.027) mg·kg-1. The ED50 and ED95 estimated by isotonic regression were 0.111 (83% confidence interval [CI], 0.096 to 0.131) mg·kg-1 and 0.182 (95% CI, 0.144 to 0.195) mg·kg-1, respectively. None of the patients required treatment for hypotension or bradycardia during anesthesia induction. CONCLUSION: Based on the ED95 of remimazolam bolus dose determined in our study, we recommend using 0.182 mg·kg-1 of remimazolam in combination with remifentanil TCI at a Ce of 3.0 ng·mL-1 for successful i-gel insertion without NMBAs in adult patients. This regimen seems effective with a low risk of hemodynamic instability during anesthesia induction. STUDY REGISTRATION: ClinicalTrials.gov ( NCT05298228 ); first submitted 6 March 2022.

RéSUMé: OBJECTIF: Le remimazolam est une benzodiazépine à action ultra-courte récemment mise au point et utilisée pour l'induction et le maintien de l'anesthésie. Toutefois, la dose efficace en bolus de remimazolam pour l'insertion de l'i-gel® (Intersurgical Ltd., Wokingham, Berkshire, Royaume-Uni) sans utiliser de bloqueurs neuromusculaires (BNM) n'a pas été bien établie. MéTHODE: Cette étude a inclus 25 adultes devant bénéficier d'une intervention chirurgicale sous anesthésie générale qui étaient éligibles à l'utilisation d'un i-gel. L'anesthésie a été induite avec des doses prédéterminées en bolus de remimazolam, à partir de 0,3 mg·kg−1 pour la première personne, sans utiliser de BNM. Toutes les personnes anesthésiées ont reçu en parallèle du rémifentanil en perfusion à objectif de concentration à une concentration au site effecteur (Ce) de 3,0 ng·mL−1. L'insertion de l'i-gel a été tentée 90 secondes après l'administration de remimazolam, et les conditions d'insertion ont été évaluées. Les doses subséquentes de remimazolam ont été diminuées ou augmentées de 0,05 mg·kg−1, en fonction du succès ou de l'échec de l'insertion de l'i-gel. RéSULTATS: La dose efficace moyenne (écart type) de 50 % (DE50) d'un bolus de remimazolam pour une insertion réussie de l'i-gel, telle que déterminée par la méthode « up-and-down ¼ de Dixon modifiée, était de 0,100 (0,027) mg·kg−1. Les DE50 et DE95 estimées par régression isotonique étaient de 0,111 (intervalle de confiance [IC] à 83 %, 0,096 à 0,131) mg·kg−1 et 0,182 (IC 95 %, 0,144 à 0,195) mg·kg−1, respectivement. Aucun·e patient·e n'a eu besoin de traitement pour une hypotension ou une bradycardie pendant l'induction de l'anesthésie. CONCLUSION: D'après la DE95 de la dose de remimazolam en bolus déterminée dans notre étude, nous recommandons d'utiliser 0,182 mg·kg−1 de remimazolam en association avec une perfusion à objectif de concentration de rémifentanil à une Ce de 3,0 ng·mL−1 pour réussir l'insertion de l'i-gel sans BNM chez la patientèle adulte. Ce schéma semble efficace avec un faible risque d'instabilité hémodynamique lors de l'induction de l'anesthésie. ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT05298228); première soumission le 6 mars 2022.

Comparison between head rotation and standard techniques for i-gel™ insertion: a randomized controlled trial.

BACKGROUND: This study evaluated the effect of head rotation on the first-attempt success rate of i-gel insertion, aiming to alleviate the effect of gravity on the tongue and reduce resistance between the device and the tongue. METHODS: Adult surgical patients were randomized to standard and head rotation technique groups. In the head rotation technique group, patients' heads were maximally rotated to the left before i-gel insertion. The primary endpoint was the first-attempt success rate. Secondary endpoints included the success rate within two attempts (using the allocated technique), time required for successful i-gel placement within two attempts, and success rate at the third attempt (using the opposite technique). RESULTS: Among 158 patients, the head rotation technique group showed a significantly higher first-attempt success rate (60/80, 75.0%) compared to the standard technique group (45/78, 57.7%; P = 0.021). The success rate within two attempts was similar between the groups (95.0% vs. 91.0%, P = 0.326). The time required for successful i-gel placement was significantly shorter in the head rotation technique (mean [SD], 13.4 [3.7] s vs. 16.3 [7.8] s; P = 0.030). When the head rotation technique failed, the standard technique also failed in all cases (n = 4), whereas the head rotation technique succeeded in five out of the seven patients where the standard technique failed. CONCLUSIONS: The head rotation technique significantly improved the first-attempt success rate and reduced the time required for successful i-gel insertion. It was effective when the standard technique failed. The head rotation technique may be an effective primary or alternative method for i-gel insertion. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov (NCT05201339).

Predicted effect-site concentrations of remimazolam for i-gel insertion: a prospective randomized controlled study.

This study is the first to report 50% and 95% effect-site concentrations (EC50 and EC95, respectively) of the new short-acting benzodiazepine, remimazolam, for the successful insertion of i-gels with co-administration of fentanyl. Thirty patients (38 ± 5 years old, male/female = 4/26) were randomly assigned into five groups to receive one of five different remimazolam doses (0.1, 0.15, 0.2, 0.25, and 0.3 mg/kg bolus followed by infusion of 1, 1.5, 2, 2.5, and 3 mg/kg/h, respectively, for 10 min), which were designed to maintain a constant effect-site concentration of remimazolam at the time of i-gel insertion. At 6 min after the start of remimazolam infusion, all patients received 2 µg/kg fentanyl. i-gel insertion was attempted at 10 min and the success or failure of insertion were assessed by the patient response. Probit analysis was used to estimate the EC50 and EC95 values of remimazolam with 95% confidence intervals (CIs). In the five remimazolam dose groups, two, two, four, five, and six of the six patients in each group had an i-gel successfully inserted. Two patients in the lowest remimazolam dose group were conscious at the time of i-gel insertion and were counted as failures. The EC50 and EC95 values of remimazolam were 0.88 (95% CI, 0.65-1.11) and 1.57 (95% CI, 1.09-2.05) µg/ml, respectively. An effect-site concentration of ≥ 1.57 µg/ml was needed to insert an i-gel using remimazolam anesthesia, even with 2 µg/kg fentanyl. Trial registration: The study was registered in Japan Registry of Clinical Trials on 19 April 2021, Code jRCTs041210009.

Effect of superior laryngeal nerve block in alleviating sore throat after application of i-gel supraglottic airway: a randomized controlled trial.

BACKGROUND: Postoperative sore throat (POST) is a common complaint after supraglottic airway device (SAD) application. Internal branch of the superior laryngeal nerve (iSLN) block has the potential to alleviate POST. The aim of this trial was to explore the effect of iSLN block in alleviating sore throat, as well as to identify the potential risk factors for POST after SAD insertion. METHODS: One hundred thirty-four patients scheduled for elective gynecological surgery were randomized to either group T: tetracaine syrup (1%) for local lubrication on i-gel supraglottic device (n = 67) or group B: i-gel insertion with water based lubricant on it and followed by bilateral iSLN block (ropivacaine, 0.375%, 2 ml for each side) (n = 67). Under ultrasound guidance, iSLN was exposed below thyrohyoid membrane. The primary outcome was the intensity of sore throat at 6 h after surgery. In addition, POST score at 0.5 h and 24 h, the severity of postoperative swallowing discomfort, acoustic analysis and complications were measured. RESULTS: Compared with tetracaine syrup for local lubrication, iSLN block resulted in a reduced intensity of POST at 0.5 h (P = 0.044, OR = 1.99, 95%CI 1.02 to 3.88) and 6 h (P < 0.001, OR = 5.07, 95%CI 2.53 to 10.14) after surgery, as well as less severity of swallowing discomfort (P < 0.001, OR = 2.21, 95%CI 1.63 to 2.99) and cough (P = 0.039, OR = 1.97, 95%CI 1.04 to 3.73). The patients after iSLN block presented lower jitter and shimmer value in acoustic analysis at 6 h after surgery (P < 0.001). CONCLUSIONS: iSLN block was effective in alleviating POST, improving voice function, as well as reducing postoperative swallowing discomfort and coughing. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2000037974) on 8th Sept 2020.

Effective dose of remimazolam co-administered with remifentanil to facilitate I-gel insertion without neuromuscular blocking agents: an up-and-down sequential allocation trial.

BACKGROUND: Remimazolam is a new anesthetic drug developed and is an ultra-short-acting agent with rapid onset and offset. The pharmacology of this drug seems to be ideal for short surgeries eligible for I-gel insertion. Therefore, this study aimed to determine the optimal bolus dose of remimazolam for I-gel insertion when co-administered with remifentanil without neuromuscular blocking agents (NMBAs). METHODS: Patients aged 19-65 years with American Society of Anesthesiologists physical status I or II scheduled for general anesthesia were enrolled. The first dose of remimazolam was 0.15 mg/kg and remifentanil was co-administered at an effect-site concentration (Ce) of 3.0 ng/mL. The dose of remimazolam for the following patient was decreased or increased by 0.05 mg/kg depending on the success or failure of I-gel insertion in the previous patient. RESULTS: The remimazolam bolus dose required for successful I-gel insertion in 50% of adult patients using modified Dixon's up-and-down method with remifentanil Ce 3.0 ng/mL and no NMBAs was 0.280 ± 0.048 mg/kg. Isotonic regression analysis showed that the 50% and 95% effective doses were 0.244 (83% confidence interval [CI] 0.213-0.313) mg/kg and 0.444 (95% CI 0.436-0.448) mg/kg, respectively. The mean time to loss of consciousness (Modified Observer's Assessment of Alertness/Sedation score < 2) was 52.2 s. Three patients (12.0%) showed a reduction in systolic blood pressure of more than 30% from baseline. CONCLUSIONS: Selecting the appropriate dose of remimazolam/remifentanil without NMBAs makes it feasible to insert the I-gel. TRIAL REGISTRATION: This study protocol was registered at http://cris.nih.go.kr (KCT0007801, 12th, October, 2022).

Comparison of SaCoVLM™ video laryngeal mask-guided intubation and i-gel combined with flexible bronchoscopy-guided intubation in airway management during general anesthesia: a non-inferiority study.

BACKGROUND: When a difficult airway is unanticipatedly encountered and the initial laryngoscopic intubation fails, a supraglottic airway device (SAD) may be placed to aid ventilation and oxygenation, and act as a conduit for intubation. SaCoVLM™, as new SAD, can offer a direct vision to guide intubation. However, no study has evaluated the performance of SaCoVLM™ video laryngeal mask (VLM) intubation and i-gel combined with flexible bronchoscopy (FB)-guided intubation in airway management during general anesthesia. METHODS: A total of 120 adult patients were randomly allocated into the SaCoVLM™ group (Group S) and i-gel group (Group I). After induction of general anesthesia, guided tracheal intubation under direct vision of the SaCoVLM™ was conducted in Group S, while Group I received FB-guided tracheal intubation using the i-gel. The success rate of SAD placement, first-pass success rate of guided tracheal tube placement, and total success rate in both groups were recorded. The time for SAD placement, time for guided tracheal intubation, total intubation time (time for SAD placement and intubation), glottic exposure grading and postoperative intubation complications (i.e., dysphagia, hoarseness, pharyngalgia, etc.) of both groups were also compared. RESULTS: The first-time success rate of SAD placement was 98% in two groups. The first-pass success rate of guided endotracheal intubation was 92% in Group S and 93% in Group I (P = 0.74 > 0.05). The total intubation time was 30.8(± 9.7) s and 57.4(± 16.6) s (95% CI = -31.5 to -21.7) in Group S and Group I, respectively (P < 0.01). The total complication rate was 8% in Group S and 22% in Group I (P < 0.05). The laryngeal inlet could be observed in the S group through the visual system of SaCoVLM™. No dysphagia or hoarseness was reported. CONCLUSION: SaCoVLM™ can reveal the position of laryngeal inlet, thus providing direct vision for tracheal intubation. SaCoVLM™ -guided intubation is faster, and does not rely on FB, compared to i-gel combined with FB-guided intubation. Besides, SaCoVLM™ has a lower post-intubation complication rate. TRIAL REGISTRATION: Chinese Clinical Trials Registry (ChiCTR2100043443); Date of registration: 18/02/2021.

Remifentanil requirement for i-gel insertion is reduced in male patients with Parkinson's disease undergoing deep brain stimulator implantation: an up-and-down sequential allocation trial.

BACKGROUND: Laryngeal mask airways have been widely used in clinical practice. The aim of this study was to investigate whether the remifentanil requirement for facilitation of i-gel insertion in Parkinson's disease (PD) patients undergoing deep brain stimulation (DBS) surgery was different from that in non-PD (NPD) patients undergoing intracranial surgery. STUDY DESIGN: An up-and-down sequential allocation trial. METHODS: Male patients aged between 40 and 64 years old were enrolled. The first patient in each group (PD and NPD) group received an effect-site concentration (Ce) of remifentanil (Minto pharmacokinetic model) of 4.0 ng.ml-1 during a target-controlled infusion (TCI) of 3.5 µg.ml-1 propofol (Marsh pharmacokinetic model). The next dose of remifentanil was determined by the response of the previous patient. The Ce of remifentanil required for i-gel insertion in 50% of patients (EC50) was estimated by the modified Dixon's up-and-down method and by probit analysis. RESULTS: The PD group included 24 patients and the NPD group included 23. The EC50 of remifentanil for i-gel insertion during a TCI of 3.5 µg.ml-1 propofol estimated by the modified Dixon's up-and-down method in PD patients (2.38 ± 0.65 ng.ml-1) was significantly lower than in NPD patients (3.21 ± 0.49 ng.ml-1) (P = 0.03). From the probit analysis, the EC50 and EC95 (effective Ce in 95% of patients) of remifentanil were 1.95 (95% CI 1.52-2.36) ng.ml-1 and 3.12 (95% CI 2.53-5.84) ng.ml-1 in PD patients and 2.85 (95% CI 2.26-3.41) ng.ml-1 and 4.57 (95% CI 3.72-8.54) ng.ml-1 in NPD patients, respectively. CONCLUSIONS: The remifentanil requirement for successful i-gel insertion is reduced in male PD patients undergoing DBS implantation during propofol TCI induction. Clinicians should closely monitor the remifentanil requirement in patients with PD. TRIAL REGISTRATION: Registered at http://www.chictr.org.cn ( ChiCTR1900021760 ).

A prospective observational study comparing two supraglottic airway devices in out-of-hospital cardiac arrest.

BACKGROUND: Airway management in patients with out of hospital cardiac arrest (OHCA) is important and several methods are used. The establishment of a supraglottic airway device (SAD) is a common technique used during OHCA. Two types of SAD are routinely used in Norway; the Kings LTS-D™ and the I-gel®. The aim of this study was to compare the clinical performance of these two devices in terms of difficulty, number of attempts before successful insertion and overall success rate of insertion. METHODS: All adult patients with OHCA, in whom ambulance personnel used a SAD over a one-year period in the ambulance services of Central Norway, were included. After the event, a questionnaire was completed and the personnel responsible for the airway management were interviewed. Primary outcomes were number of attempts until successful insertion, by either same or different ambulance personnel, and the difficulty of insertion graded by easy, medium or hard. Secondary outcomes were reported complications with inserting the SAD's. RESULTS: Two hundred and fifty patients were included, of whom 191 received I-gel and 59 received LTS-D. Overall success rate was significantly higher in I-gel (86%) compared to LTS-D (75%, p = 0.043). The rates of successful placements were higher when using I-gel compared to LTS-D, and there was a significant increased risk that the insertion of the LTS-D was unsuccessful compared to the I-gel (risk ratio 1.8, p = 0.04). I-gel was assessed to be easy to insert in 80% of the patients, as opposed to LTS-D which was easy to insert in 51% of the patients. CONCLUSIONS: Overall success rate was significantly higher and the difficulty in insertion was significantly lower in the I-gel group compared to the LTS-D in patients with OHCA.

Comparison of endotracheal intubation, laryngeal mask airway, and I-gel in children undergoing strabismus surgery.

BACKGROUND: Insertion of the advanced airway during induction of general anesthesia can cause undesirable sympathetic stimulation such as increased intraocular pressure (IOP) and hemodynamic parameters. In this study, we compared insertion of three different advanced airway devices; endotracheal tube (ETT), laryngeal mask airway (LMA) and I-gel in terms of IOP, hemodynamic changes and postoperative nausea and vomiting (PONV) following induction of general anesthesia with propofol and remifentanil in children undergoing strabismus surgery. MATERIALS AND METHODS: A total of 90 children (5.68 ± 1.49 years old) were randomly assigned to one of the three groups, ETT, LMA, or I-gel insertion as advanced airway devices IOP and also hemodynamic variables were measured before (T0 and T1) and immediately after (T2) the insertion of these airway devices, although 2 min (T3) and 5 min (T4) after it. PONV was assessed about 2 h after the completion of surgery in the recovery room. RESULTS: The mean arterial pressure (MAP), IOP, and systolic and diastolic blood pressures were significantly different between the three groups immediately (T2), 2 min (T3), and 5 min (T4) after the insertion of airway devices. The heart rate (HR) was significantly different between the three groups in all measurement times except of T0. Within-group comparisons showed that the three groups had significant changes in MAP, IOP, HR, systolic and diastolic pressure before and after airway insertion (T1 and T2). The trend in the LMA and ETT groups was descending-ascending-descending, whereas in the I-gel group, it was quite descending. There was no significant difference among the three groups in terms of PONV. CONCLUSION: As a result, our study showed that, compared with LMA and ETT, the I-gel had less impact on undesirable stress responses and seems to be superior to LMA and ETT in children undergoing strabismus surgery.

Comparison of the standard and triple airway maneuvering techniques for i-gel™ placement in patients undergoing elective surgery: a randomized controlled study.

PURPOSE: The i-gel is a supraglottic airway device with non-inflatable cuff which can suffer insertion failure if its standard placement technique is implemented. The aim of this study was to compare the placement technique proposed by the manufacturer of i-gel with the triple airway maneuver in terms of successful device insertion time and first-attempt success. METHODS: After ethics committee approval, 103 ASA I-III patients were randomly allocated to the standard or triple airway maneuver groups. In the standard Group, the i-gel was inserted in the sniffing position while, in the triple group, it was inserted using the triple airway maneuver consisting of head tilt, jaw thrust, and open mouth. The time taken for successful insertion, first-attempt success rate, i-gel position, airway complications, and hemodynamic responses were assessed. RESULTS: Between the two groups patient characteristics were similar. Time for successful insertion was significantly shorter in the triple group (20 ± 7 s) than with the standard technique (32 ± 11 s; p < 0.001). Successful insertion at the first attempt was 78% and 92% for the standard and triple group, respectively (p = 0.092). The i-gel position, airway complications, and hemodynamic responses were similar in both groups. CONCLUSION: The triple airway maneuver required less i-gel insertion time as compared with the standard placement technique. First-attempt success rates were similar with both techniques, although the triple airway maneuver was superior to the standard method as a rescue technique in failed insertions. We therefore recommend use of the triple airway maneuver in i-gel insertion.

The effect of i-gel® insertion on the accuracy of cricothyroid membrane identification in adult females: a prospective observational study.

BACKGROUND: Identification of the cricothyroid membrane is frequently inaccurate in females because of less distinct anatomy compared with males. Supraglottic airway devices cause ventral displacement of the laryngeal structures. We investigated if this would impact on the accuracy of cricothyroid membrane identification using palpation. METHODS: We recruited 64 adult females who underwent assessment by volunteer participants with and without a sited i-gel® supraglottic airway device. The primary outcome was accuracy in identifying the cricothyroid membrane. Secondary outcomes included distance from participant estimate to actual cricothyroid membrane location and perceived difficulty using a visual analogue scale. Ultrasound images were analysed to determine the effect of the i-gel® on the anatomical structures relevant to cricothyroidotomy. RESULTS: The cricothyroid membrane was identified correctly in 42/64 subjects with the i-gel® in place (66%) vs 23/64 of controls (36%; P<0.001, mean difference 30%; 95% confidence interval, 12-47%). VAS (P<0.001) and distance to the cricothyroid membrane (P<0.001) decreased in the intervention group. Analysis of the ultrasound image series showed a reduction in the mean angle between the cricothyroid membrane and anterior wall of the trachea in the i-gel® group, because of the more ventral position of the cricoid cartilage compared with control images (166° vs 151°, P<0.001). CONCLUSIONS: The presence of the i-gel® improved accuracy of identifying the cricothyroid membrane using palpation in females. The cricoid cartilage was pushed ventrally by the i-gel® in the hypopharynx, creating a more palpable prominence. It may therefore be advantageous to retain a sited supraglottic airway, rather than remove it, before performing emergency cricothyroidotomy.

Fiberoptic intubation of severely obese patients through supraglottic airway: A prospective, randomized trial of the Ambu® AuraGain™ laryngeal mask vs the i-gel™ airway.

INTRODUCTION: Airway management in severely obese patients remains a challenging issue for anaesthetists and may lead to life-threatening situations. Supraglottic airway devices, such as the i-gel™ or the AuraGain™, were developed, with the possibility to ventilate the patient or use them as a conduit for endotracheal intubation. METHODS: In our randomized prospective trial, we hypothesized a 10 seconds faster fiberoptic trans-device intubation time through the AuraGain™ laryngeal mask compared to the i-gel™ laryngeal mask in severely obese patients. We randomly assigned 44 patients to the AuraGain or i-gel group and measured trans-device intubation time after 5 minutes of successful ventilation through the device. Secondary parameters relating to the trans-device intubation success, oropharyngeal leak pressure, and parameters regarding insertion of the supraglottic airway devices were measured. Postoperative airway morbidity was determined 5 hours after surgery. RESULTS: Mean (SD) intubation time was 55.7 (5.8) seconds for the AuraGain™ vs 54.1 (8.5) for i-gel™ mask (95% CI -2.7 to 5.9; P = 0.474), respectively, on a mean body mass index (BMI) of 39.4 kg/m2 in the AuraGain™ group vs 38.9 kg/m2 in i-gel™ group. No difference could be found in the other studied parameters. CONCLUSIONS: Time for intubation through both supraglottic airway devices was similar. Attributed to fast possibility of securing the airway with both supraglottic airway devices, we believe that both, AuraGain™ and i-gel™, can be a good alternative in the airway management in obese patients.

A prospective, randomized comparison of the LMA-protector™ and i-gel™ in paralyzed, anesthetized patients.

BACKGROUND: In the present study, we compare the LMA-Protector™ and the i-gel™ in terms of adequacy of the airway seal, insertion time, ease and accuracy of insertion, and the incidence of postoperative sore throat. METHODS: In 110 anesthetized and paralyzed adult patients, the i-gel™ (n = 55) or the LMA-Protector™ (n = 55) was inserted. The primary outcome was airway leak pressure. The secondary outcomes included the first-attempt success rate, insertion time, ease and accuracy of the device insertion, ease of gastric tube placement, blood staining on the device after removal, and incidence and severity of postoperative sore throat. RESULTS: The airway leak pressure was higher with the LMA-Protector™ than with the i-gel™ (31 [7] cmH2O vs. 27 [6] cmH2O, respectively; P = 0.016). Insertion time was longer with the LMA-Protector™ than with the i-gel™ (27 [16] sec vs. 19 [16] sec, respectively, P < 0.001), but ease of insertion and the first-attempt success rate were not different between the two groups. The LMA-Protector™ provided a worse fiberoptic view of the vocal cords and more difficult gastric tube insertion than the i-gel™ (both P < 0.001). Blood staining on the device was more frequent with the LMA-Protector™ than with the i-gel™ (P = 0.033). The incidence and severity of postoperative sore throat were not different between the two groups. CONCLUSION: The LMA-Protector™ provided a better airway sealing effect than the i-gel™. However, it required a longer insertion time, provided a worse fiberoptic view of the vocal cords, and caused more mucosal injury compared to the i-gel™. TRIAL REGISTRATION: ClinicalTrials.gov (NCT03078517). Registered prior to patient enrollment, Date of registration: Mar 13, 2017.

Changes in hardness and resilience of i-gelTM cuffs with temperature: a benchtop study.

The i-gelTM is a supraglottic airway with a gel-like thermoplastic cuff. It has been suggested that the seal around the larynx improves following insertion. Perhaps the most intuitive hypothesis proposed for this is that cuff softening occurs during warming from ambient to body temperature. We investigated this using a food industry texture analyser over a wide temperature range. Size 2 and 3 i-gels were secured to a platform within a temperature-controlled water bath, which was in turn mounted on a texture analyser test stand. Both water and i-gel cuff temperatures were recorded. A spherical probe was advanced 4 mm into the surface of each i-gel at a rate of 1 mm.s-1 , then retracted at the same rate while the upward pressure on the probe was recorded. Three runs made at each of the 11 temperatures (10 °C to 60 °C, 5 °C increments) gave 105,864 data points, from which values for hardness (the peak force on the probe at maximum indentation), and resilience (the rate at which the material recovers its original shape) were calculated. Over 10 to 60 °C, the smallest hardness value expressed as a proportion of the largest was 88.2% and 89.8% for size 2 and 3 i-gels, respectively, and for resilience these were 92.8% and 86.2%, respectively. Over room temperature to body temperature range (21-37.4 °C), hardness decreased by 3.15% and increased by 0.47% for i-gel sizes 2 and 3, respectively, whereas resilience values decreased by 1.85% and 2.68%, respectively. Cuff hardness and resilience did generally reduce with warming, but the effect was minimal over temperature ranges that may be encountered during clinical use.

I-Gel is a suitable alternative to endotracheal tubes in the laparoscopic pneumoperitoneum and trendelenburg position.

BACKGROUND: The use of supraglottic airway devices (SADs) in surgeries with laparoscopic pneumoperitoneum and Trendelenburg (LPT) positioning is controversial due to concerns about insufficient pulmonary ventilation and aspiration. In this prospective, randomized-controlled trial, we evaluated whether the i-gel, a new second generation SAD, provides an effective alternative to an endotracheal tube (ETT) by comparing respiratory parameters and perioperative respiratory complications in non-obese patients. METHODS: In a randomized controlled trial, forty anesthetized patients with ASA I-II were divided into equally sized i-gel and ETT groups. We evaluated the respiratory parameters in the supine and LPT position in comparison between the two groups. The leak fraction was our primary outcome, which was defined as the leak volume divided by the inspired tidal volume. The leak volume was the difference between the inspired and expired tidal volumes. We also monitored pulmonary aspiration and respiratory complications during the perioperative period. RESULTS: In the LPT position, there were no differences in the leak fraction (median [IQR]) between the i-gel and ETT groups (6.20[3.49] vs 6.38[3.71] %, P = 0.883). In the i-gel group, notably less leakage was observed in the LPT position than in the supine position (median [IQR]: 7.01[3.73] %). This phenomenon was not observed in the ETT group. The rate of postoperative sore throat was also significantly lower in the i-gel group than in the ETT group (3/17 vs 9/11). No vomitus nor any signs associated with aspiration were noted in our patients after extubation in the follow-up prior to discharge. CONCLUSIONS: The i-gel provides a suitable alternative to an ETT for surgeries with LPT positioning in non-obese patients. TRIAL REGISTRATION: Registered at Clinicaltrials.gov NCT02462915 , registered on 1 June 2015.

Observation of ventilation effects of I-gel™, Supreme™ and Ambu AuraOnce™ with respiratory dynamics monitoring in small children.

The shortcomings of laryngeal mask airway (LMA™), such as upper airway obstruction and gastric distension or airway leakage, may limit its application in small children. The I-gel™ (I-gel), LMA-Supreme™ (LMA-S), and Ambu AuraOnce™ (Ambu) are three improvements upon these shortcomings. This study adopted respiratory dynamic monitoring to observe the ventilation parameters of the three laryngeal masks in small children. A total of 105 children were randomized into Ambu (n = 35), I-gel (n = 35), and LMA-S (n = 35) groups. Primary outcomes included leak pressure and respiratory dynamic data. Secondary outcomes included hemodynamic data and bispectral index values after induction (T0), time after successful laryngeal mask insertion (T1) and at three recording points every 10 min after insertion (T2, T3, and T4), as well as laryngeal mask related adverse reactions. The inspiratory/expiratory tidal volume per kilogram of body weight in the Ambu group was significantly different from those in the other groups (P < 0.05), while the leak pressure in the Ambu group was significantly lower (P < 0.05). At T3 and T4, the expiratory resistance values in the Ambu group were significantly lower than those in the LMA-S group (P < 0.05). We have shown that the three laryngeal masks provided secure ventilation in children <6 years of age by using continuous respiratory dynamic monitoring. We concluded that the I-gel presented a better sealing effect and fewer adverse reactions.

Insertion of i-gel™ by the reversed technique improves the success rate and reduces the time taken for its placement: A prospective, randomized, controlled, interventional trial.

BACKGROUND AND AIMS: We hypothesized that the i-gel™ supra-glottic airway can be inserted with relative ease in a reversed manner just like a Guedel's airway. MATERIAL AND METHODS: A prospective, randomized, controlled interventional trial was conducted on 100 patients to compare reversed insertion of the i-gel™ (Group R) with the conventional insertion (Group C). In Group C, i-gel™ was introduced in a conventional manner, whereas in the Group R, i-gel™ was introduced into the oral cavity with the concavity facing the hard palate. On reaching the oropharynx, the device was rotated 180° and advanced further until it fitted over the larynx. The time of insertion, ease, and placement appropriateness were compared. RESULTS: All patients completed the study. Better success rate of the first attempt insertion was achieved using the reversed technique (96% vs. 86%), but it was not statistically significant. Mean time required for i-gel™ insertion in Group R was 17.5 ± 6.9 s as compared to 20.8 ± 5.9 s in Group C, which was statistically significant. In Group R, it could be inserted within 20 s in 84% of cases, but only in 62% in Group C. The seal of the i-gel™ was similar in both the groups with the leak volumes (inspired - expired tidal volumes) being similar. CONCLUSION: Reversed insertion technique for the placement of i-gel™ resulted in appropriate placement with easier insertion and lower placement time than that with the conventional technique.

Male patients require higher optimal effect-site concentrations of propofol during i-gel insertion with dexmedetomidine 0.5 µg/kg.

BACKGROUND: The pharmacokinetics and pharmacodynamics of an anesthetic drug may be influenced by gender. The purpose of this study was to compare effect-site half maximal effective concentrations (EC50) of propofol in male and female patients during i-gel insertion with dexmedetomidine 0.5 µg/kg without muscle relaxants. METHODS: Forty patients, aged 20-46 years of ASA physical status I or II, were allocated to one of two groups by gender (20 patients per group). After the infusion of dexmedetomidine 0.5 µg/kg over 2 min, anesthesia was induced with a pre-determined effect-site concentration of propofol by target controlled infusion. Effect-site EC50 values of propofol for successful i-gel insertion were determined using the modified Dixon's up-and-down method. RESULTS: Mean effect-site EC50 ± SD of propofol for successful i-gel insertion was significantly higher for men than women (5.46 ± 0.26 µg/ml vs. 3.82 ± 0.34 µg/ml, p < 0.01). The EC50 of propofol in men was approximately 40% higher than in women. Using isotonic regression with a bootstrapping approach, the estimated EC50 (95% confidence interval) of propofol was also higher in men [5.32 (4.45-6.20) µg/ml vs. 3.75 (3.05-4.43) µg/ml]. The estimated EC95 (95% confidence interval) of propofol in men and women were 5.93 (4.72-6.88) µg/ml and 4.52 (3.02-5.70) µg/ml, respectively. CONCLUSIONS: During i-gel insertion with dexmedetomidine 0.5 µg/kg without muscle relaxant, male patients had higher effect-site EC50 for propofol using Schnider's model. Based on the results of this study, patient gender should be considered when determining the optimal dose of propofol during supraglottic airway insertion. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02268656. Registered August 26, 2014.