Securing a patent airway is a cornerstone of safe anaesthetic practice, particularly in scenarios involving trauma or anticipated difficult airways. Tracheal intubation, although a definitive method of airway management, becomes increasingly challenging when anatomical alignment is compromised, such as in patients with cervical spine injury (CSI) [1]. Cervical spine immobilization is a vital step in trauma management to prevent secondary neurological damage, yet it introduces significant difficulties in performing direct laryngoscopy due to the restriction in head and neck movement [2].

In patients with suspected or confirmed CSI, airway manipulation must be undertaken with extreme caution. Studies suggest that 3–25% of cervical spine injuries are iatrogenic, often due to improper handling during prehospital or early hospital phases [3]. Immobilization techniques, such as the application of rigid cervical collars or manual in-line stabilization (MILS), though protective, impede visualization of the glottis and limit mouth opening, significantly reducing the success of conventional intubation techniques [4]. Hence, the need for alternative airway devices that allow safe, effective intubation without cervical manipulation has become more prominent.

Fiberoptic-guided intubation (FOI) is widely accepted as the gold standard in anticipated difficult airway scenarios, especially when cervical spine movement must be minimized [5]. However, its use is limited by a steep learning curve, requirement of patient cooperation, and challenges in maintaining oxygenation during the procedure [6]. These limitations have sparked interest in using supraglottic airway devices (SADs) as conduits for FOI, offering the advantage of providing a secure airway for ventilation while also facilitating tracheal intubation.

The Intubating Laryngeal Mask Airway (ILMA), also known as Fastrach LMA, was designed specifically to enable blind or guided tracheal intubation without requiring head or neck movement [7]. Its rigid airway tube, integrated handle, and anatomical curvature are tailored to align the glottic opening with minimal manipulation. Studies have demonstrated its efficacy even in patients with immobilized cervical spines, with high success rates for both blind and fiberoptic-assisted intubation [8].

The I-GEL is a newer, second-generation SAD, notable for its non-inflatable cuff made from a gel-like thermoplastic elastomer that conforms to the pharyngeal anatomy. It offers additional advantages, such as a gastric drainage channel, an integrated bite block, and a wide, short stem facilitating easy insertion and potentially better visualization during FOI [9]. Preliminary studies have shown promising results for the I-GEL in both elective and difficult airway situations, but its role as a conduit for FOI in immobilized patients remains under-explored compared to the more established ILMA.

This study aims to address this gap by directly comparing I-GEL and ILMA as conduits for FOI in patients with simulated cervical spine immobilization. The primary focus is on evaluating the success of first-attempt intubation, with secondary outcomes including insertion time, fiberoptic view, and complication rates [10].

This prospective, interventional, randomized comparative study was conducted in the Department of Anaesthesiology, Critical Care and Perioperative Medicine at NDMC Medical College and Hindu Rao Hospital, Delhi, from August 2018 to May 2020. The study was approved by the Institutional Ethics and Scientific Committee, and written informed consent was obtained from all participants.

Study Population and Design

A total of 150 patients aged 18–65 years, belonging to the American Society of Anesthesiologists (ASA) physical status I or II, scheduled for elective surgery under general anaesthesia were included. Patients were randomized into two equal groups (n=75 each) using block randomization: Group I-GEL (I-GEL supraglottic airway device) and Group ILMA (Intubating Laryngeal Mask Airway). Patients with ASA grade III–V, inter-incisor gap <5 cm, Mallampati score >2, increased aspiration risk, or undergoing emergency or oral/pharyngeal surgeries were excluded.

Sample Size Estimation

Based on a prior study by Michalek et al., which reported success rates of 100% for I-GEL and 90% for ILMA as conduits for fiberoptic intubation, the minimum required sample size was calculated as 71 in each group with 80% power and 5% significance level. To account for potential dropouts, 75 patients were enrolled per group.

Anaesthetic Protocol

All patients underwent standard pre-anaesthetic evaluation. Premedication included oral alprazolam 0.25 mg and ranitidine 150 mg the night before surgery. On arrival in the operating theatre, standard monitoring (ECG, NIBP, pulse oximetry) was instituted. After securing intravenous access, patients received intravenous midazolam (0.03 mg/kg), glycopyrrolate (0.2 mg), and preoxygenation for 3 minutes.

Anaesthesia was induced using fentanyl (2 µg/kg) and propofol (2–2.5 mg/kg). Following confirmation of adequate mask ventilation, vecuronium (0.1 mg/kg) was administered to facilitate muscle relaxation. Manual ventilation was continued for 3 minutes with a mixture of oxygen, nitrous oxide, and isoflurane.

A rigid Philadelphia cervical collar was applied to simulate cervical spine immobilization. Depending on the group allocation, an appropriately sized ILMA or I-GEL was inserted. Proper device placement was confirmed using capnography, chest rise, and auscultation. A maximum of three attempts were allowed for SAD insertion; failure was defined as inability to insert the device within three attempts.

Fiberoptic Intubation and Measurements

A lubricated fiberoptic bronchoscope (Olympus BF Type TE2, 5.9 mm OD) preloaded with an appropriate-sized PVC endotracheal tube was introduced through the SAD. Glottic view was scored using Kapila's four-point fiberoptic grading system. The tube was railroaded into the trachea under vision, and successful placement was confirmed with end-tidal CO₂. Up to three intubation attempts were permitted; failure after three attempts was recorded.

The SAD was removed post-intubation using the ILMA stabilizing rod. Time taken for SAD insertion, FOI, and SAD removal were recorded using a stopwatch. Patients were monitored for perioperative complications and post-operative complaints (sore throat, hoarseness, dysphagia, etc.) for 24 hours.

Statistical Analysis

Data were analyzed using SPSS version 21.0. Continuous variables were expressed as mean ± SD and compared using the unpaired t-test or Mann–Whitney U test, depending on normality. Categorical variables were expressed as percentages and analyzed using the Chi-square or Fisher’s exact test. A p-value <0.05 was considered statistically significant.

Table 1: Success Rate of FOI at First Attempt
In this study, fiberoptic intubation was successfully performed at the first attempt in 98.6% of patients in the I-GEL group and in 94.7% of those in the ILMA group. Although the success rate appeared slightly higher for I-GEL, the difference was not statistically significant (p = 0.367), suggesting that both supraglottic devices are comparably effective as conduits for fiberoptic intubation in patients with simulated cervical spine immobilization.

Table 1: Success Rate of FOI at First Attempt

Table 2: Number of Attempts Taken for Insertion of SAD

A first-attempt insertion success rate of 98.7% was noted with I-GEL and 100% with ILMA. Only one patient in the I-GEL group required a second attempt. The p-value of 1.000 indicated no significant difference between the two groups. These results reflect high ease of insertion for both devices, supporting their clinical utility even in difficult airway scenarios.

Table 2: Number of Attempts Taken for Insertion of SAD

Table 3: Time Taken for Insertion of SAD
The I-GEL group demonstrated a significantly shorter mean insertion time (20.3 seconds) compared to the ILMA group (25.59 seconds), with a p-value of <0.001. This statistically significant difference highlights the faster and more user-friendly nature of I-GEL during airway establishment, an important factor in time-critical anaesthetic management.

Table 3: Time Taken for Insertion of SAD

Table 4: Time Taken for FOI
The mean time required to complete fiberoptic intubation through I-GEL was 28.55 seconds, while that through ILMA was 32.53 seconds (p = 0.023). This significant difference reinforces the relative efficiency of I-GEL over ILMA in facilitating quicker fiberoptic intubation, especially valuable in high-risk or time-sensitive cases.

Table 4: Time Taken for FOI

This study compared the effectiveness of two supraglottic airway devices, I-GEL and Intubating Laryngeal Mask Airway (ILMA), as conduits for fiberoptic-guided intubation in patients with simulated cervical spine immobilization. Both devices demonstrated high first-attempt success rates and minimal complications, confirming their clinical utility in managing difficult airways.

A key observation was the high success rate for first-attempt fiberoptic intubation, with 98.6% in the I-GEL group and 94.7% in the ILMA group. Though statistically non-significant (p = 0.367), this aligns with prior findings by Michalek et al., who reported similar success rates in manikin-based simulations, highlighting I-GEL’s reliability in challenging airway scenarios [6]. Comparable clinical trials have shown consistent results for both devices, with I-GEL showing particular utility in achieving swift and successful intubation in restricted airway conditions [7].

Regarding ease of supraglottic airway device (SAD) insertion, both groups performed exceptionally well—98.7% of I-GEL and 100% of ILMA insertions were successful on the first attempt. This finding corresponds with the results of Bhandari et al., who observed a 95% first-attempt success with I-GEL in live patients [8]. Although not statistically significant, the slightly better outcome in the ILMA group reiterates its well-established performance in airway management [9].

Significantly, I-GEL required less time for SAD insertion (20.3 seconds vs. 25.59 seconds; p < 0.001). This efficiency is consistent with results from Kleine-Brueggeney et al., who reported faster insertion times with I-GEL compared to ILMA in difficult airway settings [10]. The reduced insertion time makes I-GEL a practical choice in emergencies, where rapid airway access is crucial.

Similarly, fiberoptic intubation time was significantly shorter with I-GEL (28.55 seconds vs. 32.53 seconds; p = 0.023). This can be attributed to I-GEL’s design advantages, including a wider airway lumen and non-inflatable cuff, which reduce resistance during endoscope navigation and ETT railroading [11]. Sastre et al. demonstrated better glottic visualization with I-GEL during FOI, supporting the anatomical and practical benefits offered by its construction [12].

Demographic variables such as age, gender, weight, and height were statistically comparable between both groups, ensuring that procedural outcomes were unaffected by baseline imbalances. The female predominance observed (77.3% in I-GEL and 85.3% in ILMA) was not associated with any significant variation in success rates, echoing the device performance consistency across genders [13].

The graphical analyses further support the numerical results. Figure 5 visually affirmed the higher success rate of FOI at first attempt with I-GEL, and Figure 6 emphasized the near-perfect insertion rates for both devices. Figures 1 and 2 demonstrated balanced demographic parameters, reinforcing the homogeneity of the study sample and the internal validity of comparative outcomes. Clinically, both I-GEL and ILMA are confirmed as effective and safe conduits for fiberoptic intubation in cervical immobilization scenarios. However, I-GEL showed a statistically significant advantage in both insertion and intubation time, making it a more time-efficient option. Furthermore, I-GEL’s disposability, cost-effectiveness, and anatomical conformity offer added benefits for routine and emergency use [14]. In trauma cases and anticipated difficult airways, particularly when cervical spine movement must be minimized, supraglottic devices are essential tools. Our findings are consistent with the recommendations of the Difficult Airway Society and ASA guidelines, which endorse the use of SADs like ILMA and I-GEL in situations where direct laryngoscopy is impractical or contraindicated [15].

In this prospective randomized study comparing I-GEL and ILMA as conduits for fiberoptic-guided endotracheal intubation in patients with simulated cervical spine immobilization, both supraglottic airway devices were found to be effective and safe. I-GEL showed a slightly higher first-attempt success rate and significantly shorter times for both SAD insertion and fiberoptic intubation compared to ILMA. These differences, though modest, have important clinical implications in time-sensitive scenarios and difficult airway management.

Further multicentric studies in real-world trauma settings and among less experienced operators may provide additional evidence supporting device choice in emergency airway management.

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