Supraglottic Airway Devices (SADs) are devices that are used above the vocal cord to ventilate patients. SADs have also been called supraglottic airways and extra glottic or peri glottic airway devices. The Laryngeal Mask Airway (LMA) refers to SADs produced by the manufacturers of the LMA Classic (LMA North America [San Diego]). The acronym LM refers to a laryngeal mask manufactured by anyone other than the original manufacturers [1]. 

The I-Gel is a second generation supraglottic airway device that has a soft anatomical shaped cuff that produces an airway seal without need for air inflation. The I-Gel is notably easy to insert due to a combination of a very low coefficient of friction when lubricated and the fact there is no cuff to inflate. There are increasing numbers of formal evaluations, with most reporting positive findings [2].

The I-Gel is conventionally inserted with its concave curvature facing the mandible. Its passage from the oral cavity to the pharynx can get obstructed because of folding of tongue which can lead to fail in attempt of insertion, increase in insertion time and increase in insertion attempts. When multiple attempts are made, the I-Gel may cause trauma in the oral cavity or supraglottic structures due to the large size of its cuff and body. In addition, insertion failure will increase the time to secure the airway in the operating room or in emergency. Tongue folding is a significant obstacle preventing appropriate I-Gel placement [3].

Previous studies demonstrated that the rotational technique provides a higher success rate at the first attempt with minor pharyngeal mucosal trauma than the standard technique for insertion of the Pro Seal TM LMA [4]. In paralyzed patients, LMA insertion with triple airway manoeuvre provides wider pharyngeal space and decreases the incidence of epiglottic downfolding by LMA compared with the standard insertion method [5].

There have been no previous studies regarding the efficacy of rotational and triple manoeuvre techniques for I-Gel insertion when searching web-based data. The present study hypothesizes that the rotational and triple airway manoeuvre techniques would decrease tongue folding by reducing resistance between device and tongue, allowing the I-Gel to smoothly advance into the posterior hypopharynx compared to the standard technique. Hence it would be worthwhile to compare the three different techniques in terms of ease of I-Gel and gastric tube insertion.

Aim and Objectives

Comparison of ease of I-Gel and gastric tube insertion among three different insertion techniques of I-Gel placement i.e. standard, rotational and triple airway manoeuvre in anaesthetised paralysed adults.

Study Area

Department of Anaesthesiology, Dr. R.P.G.M.C. Kangra at Tanda, Himachal Pradesh.

Study Population

After approval by institutional ethnics committee, this study was carried out on 150 patients, 50 in each group, planned to undergo surgery under general anaesthesia with I-Gel as a primary airway device.

Study Duration

After approval by Institutional Ethics Committee (IEC), this prospective randomized study was conducted for period of 12 months including data collection, data organization, presentation, data analysis and data interpretation.

Sample Size

All patients within this duration and fulfilling our inclusion criteria were included in the study. For all three groups, 50 patients in each group were evaluated after randomization.

Inclusion Criteria

• Patients with age 18-65 years

• Patients with ASA I and ASA II

• BMI – 18.5-29.9 kg/m²

Exclusion Criteria

• Duration of surgery > 4 hours

• Mouth opening <2.5 cm

• Presence of sore throat

• Any contraindication for SGA placement e.g., facial trauma, facial deformity

• Pregnancy

• Patient at risk of aspiration e.g. patients of gastroesophageal reflux disorder, previous history of PONV and hiatus hernia

• Patient refusal to give consent for study

Study Design

The study commenced after obtaining institutional scientific review, protocol and ethics committee approval.

It was a prospective and randomized study. The patients were randomly assigned to three groups (Group-A) standard (n = 50), (Group-B) rotational (n = 50), and (Group-C) triple airway manoeuvre (n = 50) group using computer generated random numbers. Randomisation sequences were kept in opaque sealed envelopes and were opened at time of induction of GA by a person not involved in the study and handed over to anaesthesia team.

Methodology

Standard ASA fasting guidelines was followed in all patients. The patients were pre-medicated using oral alprazolam 0.25 mg a night before surgery. On patient’s arrival in operating room, the standard anaesthesia monitoring i.e. ECG, NIBP, SPO2 were applied. Following preoxygenation with 100% oxygen for 3 min, anaesthesia was induced with propofol 2 mg/kg, fentanyl 2 µg/kg and atracurium 0.5 mg/kg. The I-Gel insertion was performed after 4 minutes of administration of injection atracurium. The I-Gel was inserted by using one of the study insertion techniques. I-Gel size was standardized by weight (I-Gel size 3 for 30-60 kg and size 4 for 50 to 90 kg and size 5 for more than 90 kg).

Group-A (Standard group)

In the Group-A (Standard group) (n = 50), the I-Gel was inserted using the standard method described by AI Brain.

Group-B (Rotational group)

In the Group-B (Rotational group) (n = 50), I-Gel was inserted using the rotational technique. The I-Gel was inserted back-to-front, like a Guedel airway, and then rotated counterclockwise through 180 degrees as it was pushed into the hypopharynx.

Group-C (Triple airway manoeuvre group)

In the Group-C (Triple airway manoeuvre group) (n = 50), the technique involved the following steps described by Kuvaki et al. It involves:

• Holding the I-Gel from the middle third between the index finger and thumb of the dominant hand

• Performing a triple airway manoeuvre, the combination of head extension, mouth opening, and jaw thrust

• Pressing the I-Gel directly (front-to-back) against the hard palate and pushing it along the posterior palatopharyngeal curve using the index finger and thumb 

Table 1: Distribution of participants according to socio-demographic variables

Table 2: Ease of I-Gel insertion and gastric tube insertion

• When the index finger and thumb reach the mouth, the position of the index finger was adjusted so that it pulled upward on the lower surface of the tube

• Pushing the I-Gel into its final position holding the shaft

After I-Gel insertion, anaesthesia was maintained with isoflurane, oxygen and nitrous oxide. An anaesthesiologist with a clinical experience of 50 I-Gel insertion with standard technique placed the I-Gel in one of the three techniques and judged the effectiveness of the I-Gel based on a square-wave capnograph trace and no audible leak with peak airway pressures ≥ 10 cm H2O during manual ventilation. If air leak occurred at peak airway pressures < 10 cm H2O, the attempt was considered a failure and the I-Gel was reinserted using the same technique. 

After completion of procedure, patient was reversed with neostigmine 0.05 mg/kg and glycopyrrolate 0.01mg/kg and the I-Gel were removed when the patient was able to breathe spontaneously and open his/her eyes to command. The patients were evaluated for ease of I-Gel insertion and ease of gastric tube insertion.

Statistical Analysis

The data were recorded into Microsoft® Excel workbook 2019 and exported into SPSS v21.0 (IBM, USA) for statistical analysis. Categorical variables were expressed as frequency, percentage and compared using Chi square test. Quantitative variables were expressed as mean, standard deviation and compared using one-way analysis of variance (ANOVA). P value <0.05 was considered significant.

The present study was aimed to compare the ease of I-Gel insertion and ease of gastric tube insertion among three different techniques of I-Gel insertion i.e. standard, rotational, triple airway manoeuvre in anaesthetised paralysed adults. A total of 150 patients were included in this study at Department of Anaesthesia, Dr. R.P.G.M.C. Kangra at Tanda during the study period.

The patients were divided into 3 groups with 50 patients each. The patients in group A included standard technique, group B with rotational technique, and group C included triple airway manoeuvre.

In this study, there was no significant difference of age between three groups (p = 0.422). In this study, male to female ratio was 0.4:1 in standard group, 0.7:1 in rotational group and 0.6:1 in triple airway manoeuvre group. There was no significant difference of gender distribution between three groups (p = 0.466). In this study, there was no significant difference of weight (p = 0.395), height (p = 0.321), and BMI (P = 0.660) between three groups (Table 1).

In this study, in standard group I-Gel insertion was easy in 84% of the patients, moderate in 14% and difficult in 2% of patients. In rotational group I-Gel insertion was easy in 94% of the patients and moderate in remaining 6% of patients. In triple airway manoeuvre group, I-Gel insertion was easy in 92% of the patients and moderate in 8% of patients Ease of I-Gel insertion was statistically not significant and were comparable between all the three groups (p = 0.384) (Table 2).

There are very few studies that have shown improvement in successful placement of I-Gel by rotational or triple airway manoeuvre technique. But no randomised controlled trial comparing all three techniques is conducted till now. In our study, three groups were compared with respect to outcome of ease of I-Gel insertion and ease of gastric tube insertion.

In this study, in standard group I-Gel insertion was easy in 84% of the patients, moderate in 14% and difficult in 2% of patients, in rotational group I-Gel insertion was easy in 94% of the patients and moderate in remaining 6% of patients, in triple airway manoeuvre group I-Gel insertion was easy in 92% of the patients and moderate in 8% of patients. Ease of I-Gel insertion was statistically not significant and were comparable between all the three groups (p = 0.384).

In the study by Bhardwaj et al, I-Gel insertion was easy among 82.2%, 89%, and 84.4% in standard, reverse, and rotational technique respectively. Ease of I-Gel insertion was statistically not significant and was comparable in all three groups (p = 0.651) [6]. Our results were similar to the study done by Bhardwaj et al showing ease of I-Gel insertion was comparable in all the groups [6].

In standard group gastric tube insertion was easy in 88% of the patients and moderate in 12%, in rotational group gastric tube insertion was easy in 96% of the patients and moderate in 4% and in triple airway manoeuvre group gastric tube insertion was easy in 100% of the patients. Ease of gastric tube insertion was significantly better in triple airway manoeuvre group in comparison to other groups (p = 0.025).

In the study by Bhardwaj et al., ease of gastric tube placement was non-significant in rotational, reverse, and standard. Therefore, all the three groups were comparable (p = 0.548) [6].

In our study, gastric tube insertion was significantly better in triple airway manoeuvre than standard and rotational techniques. This might be due to better positioning and sealing in the triple airway manoeuvre technique with respect to both techniques.

Present study concluded that gastric tube insertion was significantly better in triple airway manoeuvre than standard and rotational techniques while Ease of I-Gel insertion was comparable between all the three groups.

1. Brain, A.I. "The Development of the laryngeal mask a brief history of the invention, early clinical studies and experimental work from which the laryngeal mask evolved." European Journal of Anesthesiology Supplement, vol. 4, 1991, pp. 5–17.

2. Gatward, J.J. et al. "Evaluation of the size 4 i-gel airway in one hundred non-paralyzed patients." Anaesthesia, vol. 63, 2008, pp. 1124–1130.

3. Taxak, S., and A. Gopinath. "Insertion of the i-gel airway obstructed by the tongue." Anesthesiology, vol. 112, 2010, pp. 500–501.

4. Hwang, J. et al. "Comparison of two insertion techniques of proseal laryngeal mask airway: standard versus 90-degree rotation." Anesthesiology, vol. 110, 2009, pp. 905–07.

5. Eglen, M. et al. "Comparison of three different insertion techniques with lma-unique™ in Adults: Results of a Randomized Trial." Revista Brasileira de Anesthesiologic, vol. 67, 2017, pp. 521–526.

6. Bhardwaj, M. et al. "A prospective randomized trial to compare three insertion techniques for i-gel™ placement: standard, reverse, and rotation." Indian Journal of Anesthesia, vol. 64, 2020, pp. 618–623.