European Journal of Cardiovascular Medicine

Ensuring the patency of the airway is a fundamental aspect of administering general anaesthesia. An anesthesiologist's primary duty is to ensure the patient receives adequate ventilation. When comparing supraglottic airway devices (SAD) to endotracheal tubes, SADs have clear advantages. They allow for faster and more reliable placement, maintain stable blood pressure during the start and end of anaesthesia, improve oxygenation during recovery, and reduce the occurrence of postoperative sore throat and voice changes, leading to higher patient satisfaction. A diverse range of supraglottic airway devices are available for use in surgeries that require general anaesthesia, in order to prevent the hemodynamic response that is typically associated with endotracheal intubation.[1]

The LMA Classic™ is a frequently utilised supraglottic device. The device is furnished with an inflatable cuff that is used to close the perilaryngeal space. Precise placement and appropriate force and capacity within the cuff are essential for achieving optimal performance and minimising the risk of problems. [2-6]

The i-gel™ is a supraglottic device that is specifically designed to conform to the peri-laryngeal and hypo-pharyngeal structures. Unlike other devices, I gel is not having an inflatable cuff. The i-gel™ is made of  styrene ethylene butadiene styrene, which has  a gel-like consistency. This allows igel  to provide a seal in patients with  different airway anatomy . The purported benefits encompass effortless insertion and utilisation with less tissue compression and congestion, as well as reduced risk of airway problems and enhanced stability after insertion. A prior anatomical investigation conducted on cadavers has demonstrated that the i-gel™ may effectively establish a satisfactory seal around the larynx without the need for an inflatable cuff. Additionally, it possesses specific functionalities intended to facilitate the insertion of a gastric tube into the stomach. [7-9]

Supraglottic devices (LMA Classic™ or i-gel™)offer distinct advantages over the Endotracheal tube in terms of increased speed and reliability of placement, maintaining hemodynamic stability during induction and emergence.  But they are also prone for complications like tissue edema, nerve injury , dysphagia  ,dental trauma and even dreadful laryngospasm which can eventually lead to brain death if not timely intervened.

Even though there are multiple published studies comparing these two supraglotic devices in adults, there are only limited studies in paediatric population especially in south India. Hence the present study was conducted to compare LMA Classic™ and i-gel™ in terms of device related adverse effects, complications and hemodynamic changes in pediatric population undergoing General anesthesia for Ophthalmic surgeries.

The present prospective observational study was conducted at Regional Institute of Ophthalmology, Trivandrum among pediatric patients admitted for ophthalmic surgery during the study period of one year. Patient’s guardians were asked to sign an informed consent form before study commencement. Ethical permission was taken from institutional ethical committee of allied institution.

Hence the minimum sample size required in each group was 54.

Inclusion criteria

• Children in the age group of 6 to 15 year.
• Children satisfying criteria ASA  I and ASA II
• Children posted for short ophthalmic surgery.

Exclusion criteria

• Children having congenital Respiratory tract and cardiovascular abnormality.
• Children expected with difficulty in mask ventilation and Intubation.
• Children who are unable to report pain.
• Refusal for parental consent.
• Patients with acute repiratory infection.

Methodology – After obtaining informed consent form parents/guardians patients were  allotted randomly into two groups using  the sealed envelope method, Group A -LMA Classic and Group B i-gel. Induction & maintenance of general anesthesia was done by the Principal Investigator and the anesthesia post graduate students collected the data.  Hemodynamic parameters and respiratory parameters were measured by the help of multipara monitor. Heart rate, systolic and diastolic BP, end tidal CO2 and  SPO2  were recorded as per standard protocol. Presence or absence of post extubation cough,   lip/dental trauma, blood in the device, laryngeal spasm was noted.  Presence of sore throat, difficulty in swallowing, change in voice and cough was noted at 1hr, 4hr and 24 hr  after extubation. Comparison was done on the recorded parameters to find out which type of supraglotic device is better for pediatric patients.

Statistical analysis

Quantitative and Categorical variables were expressed as frequency and mean ± SD respectively. Between the groups Independent t test was used to compare quantitative parameters.  Association of method with categorical variables were done with Chi-square test. For statistical interpretations, p<0.05 was considered as statistically significant. statistical software package SPSS, version 20.0 was used to perform statistical analysis.

Table 1 displays the demographic characteristics of the patients in the two groups. The variables compared include sex, age, weight, and ASA physical status. No significant differences were observed.

Table 1: Demographic characteristic of the patients

The hemodynamic parameters of the two groups are compared and displayed in Table 2. There was  no statistically significant difference (p>0.05)  noted  in pulse rate, systolic /diastolic BP and SpO2 at different time intervals when  compared to the baseline values.

Table 2 :Distribution pattern of hemodynamic parameters 

Table 3 shows a comparison of respiratory parameters. There was no statistically significant difference (p>0.05) seen among  groups in terms of SpO2 and End Tidal Carbon Dioxide (EtCO2).

Table 3: Distribution of respiratory parameters between study groups

When postoperative complications after  the removal of air way devices were compared between two groups, there was no statistically significant difference (p>0.05), except for dysphagia, (table 4). In the LMA group, a mild lip/dental damage was observed in 6%. In the I-gel  group, 9% experienced a mild lip/dental injury.
One instance 2% of mild laryngospasm was found in the group where LMA was inserted, while 6% of mild laryngospasm were observed in the group where I-gel was placed.
At one hour after the operation, 20%  of LMA and 18% of I-gel reported experiencing a mild sore throat. After 24 hours following the surgery, no instances of sore throat were observed in Group-B. However, 8% experienced sore throat after 24 hours of removing the LMA. It was discovered that 22% who had an LMA inserted experienced dysphagia within 1 hour of its removal. Additionally, 3% experienced dysphagia within 1 hour of removing the I-gel. There were no recorded cases after 24 hours. Dysphonea was detected in 3% case in both group after 1 hour but all of them recovered in 24 hours after removal of the devices.

Table 4 :Complications reported among study groups

Supraglottic airway devices have revolutionized the field of anesthesia and are currently being widely employed as a superior substitute for  tracheal intubation, because of its lesser  complications. These air way devices can be utilized in elective minor procedures where  intubation is not required, as well as in emergency situations during cardiopulmonary resuscitation (CPCR) for patients with challenging intubation or when it is not possible to intubate and ventilate. Second generation devices are specifically developed to enhance safety by addressing increased oropharyngeal leak pressures and reducing the risk of aspiration. Second generation supraglottic airway devices (SADs) has the capability of positive pressure ventilation, are constructed using disposable materials, incorporate bite blocks, and exhibit improved suitability for facilitating the installation of tracheal tubes.[11]

Nevertheless, there are still some issues associated with these devices, such as insufficient ventilation, which can lead to airway injury and an increased risk of pulmonary aspiration of gastric contents.[12,13] Successful utilization of these devices requires meticulous patient selection and exceptional technical proficiency.[11]

The I-gel and LMA are second-generation supraglottic airway devices designed for use under anesthesia. The device is equipped with an elliptical bite block that reduces axial rotation, as well as a small drain tube that prevents the displacement of the gastric tube and the inflation of the stomach during breathing.[14] Hence the present study was conducted to compare LMA Classic™ and i-gel™ in terms of device related adverse effects, complications and hemodynamic changes in pediatric population undergoing General anesthesia for Ophthalmic surgeries.

In our study, the two groups exhibited similar demographic characteristics, including age sex, weight, and ASA status.  No statistically significant difference was noted between the two groups (p>0.05) regarding the above-mentioned factors. These above  results align with  discoveries made by Park et al.[15]

Both  the groups were  compared for Hemodynamic parameters , such as pulserate, Systolic BP, and Diastolic BP, from baseline, immediately after device insertion, as well as at 5 minutes and 10 minutes after the introduction of device. The levels of oxygen saturation and end tidal CO2 remained consistent during the entire duration of the trial.

No significant changes were noted  in the baseline  and post-insertion parameters like PR, systolic BP, diastolic BP, EtCO2 and SpO2. Gupta et al made a similar observation on a sample of 60 patients, divided into two groups of 30 each.[16]

In our investigation on the extraction of SGA devices, we did not find any notable postoperative problems in either of the groups. Five individuals in the I-gel group and three instances in the LMA group exhibited minor dental injuries. Laryngospasm was observed in one and three patients in each of the two groups. The occurrence of a sore throat was more frequent in the LMA group after 1 hour and 24 hours, but the difference was not statistically significant at 1 hour. Park et al and Belena et al made comparable discoveries.[15,17] Similarly Ragazzi et al. found that the incidence of sore throat was higher in the LMA group compared to the I-gel group.[18] At one hour, the LMA group reported a higher incidence of dysphagia compared to the I-gel group . None of the patients experienced dysphagia after 24 hours. The study conducted by Liew et al also found that there was a similar occurrence of dysphagia  in 7 cases of LMA group and  no cases in the I-gel group out of a total of 50 cases.[19] Small sample and study at a single centre serves as a limitation to our research.

In our study  we found that both LMA and I-gel are appropriate for ventilating the  Pediatric patients  during ophthalmic surgery and can serve as a substitute for endotracheal intubation. These devices are easy to use and do not result in any major changes in the patients' hemodynamics . Both I-gel and LMA  showed  minimal complications after procedure , such as lip/dental damage, laryngospasm, sore throat, and dysphonia. However, the occurrence of dysphagia was higher with the LMA compared to the I-gel. Therefore, I-gel provides superior airway control compared to LMA for patients who are undergoing brief surgical operations while under general anesthesia.

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