European Journal of Cardiovascular Medicine

The most important responsibility of an anesthesiologist is to provide adequate ventilation for the patient. The variety of airway devices are available today which may be broadly classified as supraglottic airway devices which are employed to protect the airway in both elective as well as emergency situations.¹ They improved speed and reliability of placement, keeping hemodynamic balance all through induction and emergence, higher oxygenation during the emergence and increased patient’s satisfaction by reducing the incidence of postoperative sore throat and voice alteration.²

The Supraglottic Airway Devices (SAD’s) offer various advantages such as avoiding the pressor response associated with endotracheal intubation as well as lesser laryngo-tracheal morbidity. It also allows general anaesthesia to be administered without the use of neuromuscular blockade. Because of their ease of insertion, simplicity, and good ventilation, they have become extremely popular. ^3,4

Nowadays a modification of a LMA commonly known as I-gel is gaining popularity as an alternative to tracheal intubation in general anaesthesia.⁵ I-Gel is a true anatomical device without an inflatable cuff which fits into the laryngeal, pharyngeal and para laryngeal framework mirroring the shape of epiglottis, aryepiglottic folds, pyriform fossa, parathyroid, posterior cartilages and spaces. The non-inflatable cuff snugly fits onto the above structures and provides a tight seal sufficient for maintaining spontaneous as well as intermittent positive pressure ventilation. Present study was aimed to study I- Gel Device in patients posted for short duration elective surgeries in a tertiary care center.

Present study was a prospective, interventional study, conducted in the Department of Anaesthesiology, Dr Vasantrao Pawar Medical College, Hospital & Research Centre, Adgaon, Nashik, India. Study period was from August 2019 to December 2021. Study approval was obtained from the institutional ethical committee.

Inclusion criteria

• All patient aged 21-60 years of both sexes, with BMI range of 20-25 kg/m²,
• American society of anaesthesiologist classification 1 and 2,
• Mallampatti grade 1 and 2,
• undergoing different surgical procedures under general anesthesia with spontaneous ventilation in supine position for not more than 1 hour, willing to participate in present study

Exclusion criteria

• Patients with reported history of hypersensitivity for one or more of the medications and latex.
• Patients having abnormalities of the neck, upper respiratory tract.
• Patients having a history of obstructive sleep apnoea or patients who underwent thoracic, abdominal & neurosurgical operation.
• Emergency surgeries
• Patients with hepatic and renal dysfunction.
• Patients with cardiovascular disorders.
• Patients with any known drug allergies.
• Pregnant patients
• Patients with full stomach
• Mouth opening less than 2 fingers.

Study was explained to patients in local language & written informed consent was taken for participation in study. All patients included in the study were kept NBM orally for solids and liquids for at least 6 hours before surgery. On arrival of the patient in the operating room, 20G IV cannula was inserted and infusion of ringer’s lactate was started.

The patient was connected to multipara standard ASA monitors which records heart rate (HR), Non-invasive Blood pressure (NIBP), Peripheral oxygen saturation (SPO2) and continuous Electrocardiogram (ECG). Soft pillow was kept below the patient's head before induction, to achieve flexion of neck and extension of head. The baseline heart rate, systolic, diastolic blood pressure and saturation were recorded. Mean arterial pressure (MAP) was estimated.

I-Gel (2^nd generation supraglottic airway device) was used in all patients. According to the patient’s weight, I-gel size was chosen. Posterior surface of the device was lubricated with lignocaine jelly. Pre-medication was given with: Inj. Ondansetron 0.08 mg/kg, Inj. Midazolam 0.05 mg/kg, Inj. Fentanyl 2mcg/kg intravenously. The patient was pre-oxygenated with 100% oxygen for 3 mins with Bain’s circuit and face mask. Induction was done with Inj. Propofol 2 mg/kg of body weight (till abolition of eyelash reflex) and induction of anaesthesia was confirmed.

After achieving adequate depth of anesthesia, I- gel was inserted and end tidal carbon dioxide (EtCO2) monitoring initiated. Recommended size of I-Gel and maximum size of gastric tube which can be inserted through it.⁶

Sniffing the morning air position was given to the head of the patient. Same anaesthesiologist performed the insertion of I gel in all patients. When insertion of device or ventilation of patient was not possible even after 3 attempts, the patient was intubated and case was continued. These patients were excluded from our study.

In cases of inadequate ventilation of the lungs, following airway maneuvers were allowed: chin lift, jaw thrust, head extension or flexion on the neck. After any maneuver, adequacy of ventilation was re-assessed and air entry on both sides of the lung was confirmed by auscultation. Anaesthesia was maintained with oxygen support ventilation and Sevoflurane. SpO2 was maintained above 95% in all patients. Haemodynamic monitoring including heart rate, systemic blood pressure, continuous oxygen saturation, and end-tidal CO2 monitoring and electrocardiogram. Gastric Insufflation observation before I-Gel Insertion, immediately after insertion and later on at 5, 10 & 15-minutes interval from the time of insertion.

At the end of the surgery, anaesthetic agents were discontinued allowing smooth recovery of consciousness in patient. Suctioning was done. The device was removed in a deep plane of anaesthesia. Oxygen support was given until the patient regains complete consciousness and obeys verbal commands. Hemodynamic stability of the patient was ensured before shifting the patient outside of the operating room. Each patient was examined for lip or pharyngo-laryngeal injury and was again examined after 24 hours for postoperative sore throat, dysphagia and cough.

Data was collected and compiled using Microsoft Excel, analyzed using SPSS 23.0 version. Frequency, percentage, means and standard deviations (SD) was calculated for the continuous variables, while ratios and proportions were calculated for the categorical variables. Difference of proportions between qualitative variables were tested using chi- square test or Fisher exact test as applicable. P value less than 0.05 was considered as statistically significant.

In the study 77 patients participated. The youngest patient was 22 years old and the oldest was 60 years. Most common age group amongst the study population was 40-49 years (46 %) followed by 20-29 years (20%), 30 -39 years (17 %) and 40-60 years (4%). There were more females (62 %) amongst the study population as compared to male (38 %).

Average body mass Index was in the range of 23 -23.9 (40.25%) and 24 -25 (28.57 %). The mean for body mass Index was 23.48 and SD was 1.006. Maximum duration of surgery was in the range of 20-30 minutes with 49 patients (64 %) followed by 21 patients in the range of 10 -20 minutes (27%). The mean surgery time noted was 23 minutes.

Table 1: General characteristics

It was observed that in 85% of patient’s insertion of I-Gel was successful in the first attempt. The second attempt of insertion was needed for 10 % of patients & the third attempt of insertion was needed only in 5% of patients.

Table 2: Number of attempts of I-gel Insertion

The heart rate, Mean Arterial Blood pressure (MAP), End tidal Carbon dioxide and Oxygen saturation was observed of each patient before administration I-Gel, immediately after administration and after 5, 10 and 15 minutes from insertion and the mean was calculated.

The mean heart rate was 93.81 ± 8.80 before the administration of I gel and at the end of 15 minutes the mean studied was 74.60 ± 4.38. The mean difference in all the four intervals and before insertion of I-Gel was within the range and had no major difference in Heart rate.

Table 3: Heart Rate (beats per minute)

The mean Arterial Blood pressure noted was 86.98 ± 5.26 before the administration of I gel. At the end of 15 minutes the mean studied was 76.50 ± 4.66. The mean difference in all the four intervals and before insertion of I-Gel was within the range and had no major difference in Mean Arterial blood pressure level.

Table 4: Mean Arterial Blood Pressure (mm of Hg)

The Mean Tidal Carbon dioxide noted was 31.84 ± 1.95 before the administration of I gel. At the end of 15 minutes the mean studied was 29.99 ± 1.38. The mean difference in all the four intervals and before insertion of I-Gel was within the range and had no major difference in Mean Tidal Carbon dioxide level.

Table 5: Mean End Tidal Carbon dioxide (mm of Hg)

The mean Oxygen Saturation percentage noted was 99.41 ± 0.67 before the administration of I gel. At the end of15 minutes the mean studied was 99.70 ± 0.72 The mean difference in all the four intervals and before insertion of I-Gel was within the range and had no major difference in Mean Oxygen Saturation in percentage (%).

Table 6: Oxygen Saturation in percentage (%)

The gastric insufflation was absent in all patients after the administration of I-Gel, which shows that I-Gel has better sealing pressure and it fits well with the laryngeal anatomy.

Table 6: Gastric Insufflation

It was observed that only 12 % patients reported sore throat, only 10 % patients reported postoperative cough after the safe removal of I-Gel. Dysphagia was reported by only 7 % after safe removal of I-Gel.

Table 7: Observation after I-Gel Removal

The supraglottic airway devices have radically changed anaesthesia practice and have become a key component of airway management in patients. Newer second generation supraglottic airway devices like I-Gel have truly revolutionized the approach of general anaesthesia in various surgeries.

This study was designed to gain better knowledge about the safety and efficacy of I-Gel by assessing ease of insertion of I-Gel, incidence of gastric insufflation and postoperative complications like sore throat, cough and dysphagia along with hemodynamic stability of the patient.

Ease of insertion of I-gel was assessed based on attempts of insertion required. I-gel was successfully inserted in the first attempt in 66 (85%) patients amongst 77 patients, 8 (10%) patients required two attempts and 3 (5%) patients required three attempts. These findings show a high success rate at first attempt securing an effective airway and providing adequate ventilation. In many therapeutic trials, first attempt success rates obtained were between 85% to 95 %.

The use of I-Gel in 2049 patients undergoing general anaesthesia was recently reported in a large observational cohort study. The authors reported a total success rate of 94.30 % to 95.9% for first attempt insertion. Some failures were due to the impossibility of insertion (2%) and inadequacy of ventilation (5%).⁷

The firmness of the shaft of the I-gel and its alignment with natural oropharyngeal structures allows the device to be easily and successfully inserted by grasping the proximal part, which helps to glide the leading edge against the hard palate into pharynx.

Hemodynamic stability of the patients was analyzed by recording heart rate (HR), mean arterial pressure (MAP) and ECG before inserting I-gel and immediately after inserting I-gel and then at intervals of 5 minutes, 10 minutes and 15 minutes. These hemodynamic parameters were assessed and statistically analyzed. In comparison to the baseline values, it was observed that there was no significant rise in HR, MAP and there were no significant changes noted in ECG immediately after insertion if I-gel and then at 5 minutes, 10 minutes and 15 minutes intervals. Insertion of I-gel does not lead to increase in sympatho-adrenal activity since it does not require laryngoscopy hence no oropharyngeal and laryngotracheal stimulation. Thus, it clearly suggests that I-gel is a soft gel elastomer structure that easily aligns with oropharyngeal and Para laryngeal structures and thus offers more hemodynamic stability on insertion and maintenance and extubation.

Furthermore, on comparison of hemodynamic response to insertion of I-gel and laryngeal mask airway (LMA) or an endotracheal tube in one of the studies, it was found that Insertion of the I-gel device offers better stability of Intraocular pressure (IOP) and the haemodynamic parameters as compared with insertion of an endotracheal tube or LMA in patients undergoing elective non-ophthalmic surgery.²

Values of end tidal carbon dioxide (EtCO2) and oxygen saturation in percentage (SPO2) were compared before and after insertion of I-gel and it was concluded that adequate oxygenation and ventilation was provided through I-gel device throughout the procedure as it forms effective seal around the glottis along with maintaining patient’s hemodynamic stability.

All patients were clinically observed for evidence of abdominal distension intraoperatively after insertion of I-gel to rule out incidence of gastric insufflation, while the patient is breathing spontaneously. Our study showed that none of the patients showed any signs of abdominal distension and no incidence of regurgitation was observed. According to the I-gel user guide,⁸ air venting out through the gastric channel seems to be a useful mechanism to protect against gastric insufflation. Nasogastric tube can be inserted and gastric contents can be suctioned out through gastric channel if regurgitation is suspected or noticed during anaesthesia.

We observed that out of 77, only 9 patients (12%) developed sore throat after removal of I-gel device, only 7 patients (10%) reported cough and 3 patients (7%) complained of dysphagia postoperatively. There are very few researches focusing on the incidence of postoperative side effects related to the I-gel device.

Donaldson et al.,⁹ found that 17 percent of patients in the I-Gel group had a sore throat immediately after the surgery, which decreased to 12 percent after 24 hours. The sore throat was described as very mild. The percentage of those who had difficulty swallowing was 4% immediately after surgery and 3% after 24 hours. Other symptoms include mouth discomfort, neck pain, tongue numbness, coughing, and hiccoughs.

Serious complications like bronchospasm and aspiration were not noted in any of the patients. Also, a study conducted by Keijzer et al.,¹⁰ observed that I-Gel had a 6 % rate of postoperative sore throat at 1st hour, 24 hours, and 48 hours, which was much lower than the LaPremiere disposable Laryngeal mask. Swallowing difficulties reported with the I-Gel were around 4% at 24 hours and then dropped to 3% after 48 hours. The researchers concluded that the I-Gel performed better than the LaPremiere disposable Laryngeal Mask in terms of postoperative complaints.

Thus, from our study we came to the conclusion that I-Gel is safe and can be effectively used in short duration (up to 30 minutes) surgeries while patients breathing spontaneously since it is easy in insertion and is designed to form non-inflatable anatomical seal with thermoplastic elastomer by mirroring around perilaryngeal framework avoids trauma by tissue compression hence causing minimal side effects.

I-Gel is a simple, effective, and safer supraglottic airway device, which is easy to insert and secures airway successfully without requiring much airway manipulation. Use of proper sized I-Gel suits to be ideal and seems to be an efficient and safe device for adult airway management in short duration (up to 30 minutes) minor surgeries while patient breathing spontaneously.

Conflict of Interest: None to declare

Source of funding: Nil

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