|Year : 2015 | Volume
| Issue : 4 | Page : 521-528
I-gel against proseal laryngeal mask airway and endotracheal tube during minor surgical procedures: a comparative study
Hala E Zanfaly, Ali M Ali Hassan
Department of Anesthesia and Intensive Care, Faculty of Medicine, Zagazig University, Zagazig, Egypt
|Date of Submission||03-Feb-2015|
|Date of Acceptance||25-Jun-2015|
|Date of Web Publication||29-Dec-2015|
Hala E Zanfaly
Department of Anesthesia and Intensive Care, Faculty of Medicine, Zagazig University, 57 Elshaheed Ahmd Esmaeel St, Kawmia Square, Zagazig
Source of Support: None, Conflict of Interest: None
I-gel is the second generation of supraglottic airway devices with a noninflatable cuff that has several potential advantages over other supraglottic airway devices.
The aim of this study was to compare I-gel with proseal laryngeal mask airway (PLMA) and endotracheal tube (ETT) during elective minor surgical procedures using controlled ventilation.
Design and setting
A prospective, randomized, comparative study.
Patients and methods
A total of 60 adult female patients ASA I-II scheduled for elective breast lumpectomy surgery under general anesthesia with positive pressure ventilation were divided equally into three groups (20 patients each): group I used I-gel, group II used PLMA, and group III used ETT for airway maintenance. The three devices were compared with regard to the insertion characteristics, the ease of gastric tube insertion, tidal volumes, leak volumes, airway sealing pressures, hemodynamics, gas exchange parameters, and postoperative airway complications.
The mean insertion time for I-gel (9.8 ± 2.5 s) was significantly shorter than that of PLMA (15.4 ± 3.2 s) and ETT (14.1 ± 2.1 s) (P < 0.001). The I-gel group (19/20) and the ETT group (18/20) showed a significantly easier insertion compared with the PLMA group (13/20) (P < 0.05). There was a significant increase in the mean arterial blood pressure after the insertion of the airway device in the ETT group (110 ± 13 mmHg) compared with the I-gel group (100 ± 10 mmHg) and the PLMA group (102 ± 11 mmHg) (P < 0.05). There was a significantly lower incidence of hoarseness, nausea, regurge, vomiting, and dysphagia in the I-gel and the PLMA groups when compared with the ETT group.
I-gel is an effective alternative device to PLMA and ETT during minor surgical procedures using controlled ventilation as it produces minimal hemodynamic changes, less airway morbidity, and is rapid and easy to insert.
Keywords: endotracheal tube, I-gel, minor procedure, proseal laryngeal mask airway
|How to cite this article:|
Zanfaly HE, Ali Hassan AM. I-gel against proseal laryngeal mask airway and endotracheal tube during minor surgical procedures: a comparative study. Ain-Shams J Anaesthesiol 2015;8:521-8
|How to cite this URL:|
Zanfaly HE, Ali Hassan AM. I-gel against proseal laryngeal mask airway and endotracheal tube during minor surgical procedures: a comparative study. Ain-Shams J Anaesthesiol [serial online] 2015 [cited 2021 Oct 22];8:521-8. Available from: http://www.asja.eg.net/text.asp?2015/8/4/521/172727
| Introduction|| |
Airway management of patients has progressed from using endotracheal tubes (ETTs) to less invasive supraglottic airway (SGA) devices  . It is well known that the ETT is the most efficient in securing the airway with effective ventilation  . However, under some conditions, tracheal intubation fails because of a difficult airway, trauma, or an inexpert person  . SGA devices are documented in these situations and may be a life-saving procedure as supported by the European Resuscitation Council guidelines for resuscitation , .
SGA devices are usually used for minor surgical procedures during spontaneous or controlled ventilation  .
In 1989, Archie Brain described the first SGA device, the classic laryngeal mask airway (LMA)  .
Unlike ETT, SGA devices do not require a laryngoscope or a muscle relaxant for the insertion. It offers a safe airway for spontaneous or controlled ventilation. However, high positive-pressure ventilation must be avoided  . The proseal laryngeal mask airway (PLMA) was described by Archie Brain in clinical practice in 2000 with its advantages over the classic LMA, such as the modified cuff to improve the seal around the glottis and a drain tube that prevents gastric insufflations and allows the placement of the gastric tube ,,, .
I-gel (Intersurgical Ltd, Wokingham, UK) is a second-generation SGA device. It was introduced to overcome the limitation of other SGA devices  .
I-gel is made up of a thermoplastic elastomer that is soft, gel-like, transparent, and structured to be fit to the perilaryngeal and hypopharyngeal structure, so that it does not require an inflatable cuff  . There is also an independent gastric drain tube that allows the insertion of the gastric tube for the aspiration of air and the residual gastric fluid. A widened flat stem of I-gel has a rigid bite-block that prevents the occlusion of the airway during recovery  .
This study hypothesized that I-gel is the best SGA device to be used as an alternative to PLMA and ETT because it is inserted rapidly and easily, with better maintenance of hemodynamics.
I-gel is more reliable than cuffed ETT in patients with high risk and an anticipated difficult airway because of the ease of insertion and the maintenance of hemodynamic stability  .
Different studies proved that the I-gel airway is a better alternative device when compared with PLMA because of its ease of insertion and the maintenance of anesthesia , .
Another study suggests that I-gel can be used as an alternative to ETT during pressure-controlled ventilation (PCV) with moderate airway pressure  .
The aim of this study was to compare I-gel with PLMA and ETT with respect to the ease of insertion, the time of insertion, the number of insertion attempts, the ease of gastric tube insertion, tidal volumes, the leak volume, the airway sealing pressure, the hemodynamic response, oxygen saturation, end-tidal carbon dioxide, and postoperative airway complications during elective minor procedures using controlled ventilation.
| Patients and methods|| |
This prospective randomized comparative study was carried out at the Anesthesia Department of Zagazig University Hospitals from December 2013 to November 2014 after obtaining approval from the local Ethics Committee and a written informed consent from each patient.
A total of 60 female patients undergoing minor elective procedures (breast lumpectomy) under general anesthesia (with the predicted anesthesia duration of 45-60 min) using controlled ventilation were enrolled in this study.
Patient selection was based on certain inclusion and exclusion criteria.
- Age: 25-50 years.
- Female patients.
- ASA I-II.
- Mallampati 1 or 2.
The patients were allocated randomly into three equal groups (n = 20) using sealed opaque numbered envelops:
- Patients with a reported history of any pathology of the neck or the airway.
- A BMI>35 kg/m 2 .
- Significant acute or chronic lung diseases.
- Patients with known difficult airway.
- Patients at risk of aspiration (full stomach, hiatus hernia, or gastroesophageal reflux).
- Pregnant women.
- Emergency surgeries.
Group I: The I-gel group.
Group II: The PLMA group.
Group III: The ETT group.
The anesthetic technique was standardized for all patients. Intravenous access was secured and standard monitors were attached using ECG, a pulse oximeter, a capnograph, and noninvasive blood pressure.
All patients were premedicated with midazolam (0.02 mg/kg) and ranitidine (50 mg) intravenously.
After preoxygenation, anesthesia was induced with propofol (2 mg/kg) and fentanyl (1 mg/kg). Neuromuscular blockade for the insertion of the airway device was achieved in all groups with cis-atracarium (0.15 mg/kg).
After an adequate depth of anesthesia had been achieved, each device was inserted.
In group I, I-gel was used. The size was chosen according to the patient's body weight (size 3 was used for patients <50 kg, size 4 was used for those between 50 and 90 kg, and size 5 was for those over 90 kg in weight).
The back, sides, and the front of the I-gel were lubricated with a thin layer of lubricant. The lubricated I-gel was inserted according to the manufacturer's instruction manual  .
In group II, PLMA was used. The appropriate size of PLMA was chosen according to the weight of the patients. It was lubricated with a water-soluble jelly and then inserted according to the manufacturer's introducer technique  . Cuff of the LMA Proseal was inflated with air to 60 cm H 2 O pressure and maintained at this pressure throughout anesthesia using portex cuff inflator/pressure Gauge (SIMS portex limited, Hythe, UK).
In group III, ETT was used. The size was 7-7.5 D for female patients.
The gastric tube was inserted in the groups I and II through the gastric inlet, but in group III, it was inserted orally.
In each group, the breathing system was connected, and then the adequacy of ventilation was assessed by adequate chest movement, chest auscultation, stable oxygenation, square waveform on capnography, no audible leak of gases, and a lack of gastric insufflation  .
Maintenance of anesthesia
Anesthesia was maintained with oxygen, isoflurane (1-2%), and cis-atracurium 0.03 mg/kg; patients were allocated on PCV, at a rate of 12-14 breaths/min, and an inspiratory-to-expiratory ratio of 1 : 2, with no positive end-expiratory pressure.
At the end of the surgery, reversal of the neuromuscular blockade by 0.05 mg/kg neostigmine and 0.01 mg/kg atropine was performed. Removal of the airway devices and the gastric tube from each patient was performed when the patients were fully recovered and obeyed the command with adequate spontaneous ventilation and protective airway reflexes.
- Age, weight, and the duration of the surgery were recorded.
- The insertion time was recorded; it is the time from the start of the insertion of the airway device until securing the airway and confirmation of its effectiveness.
- The ease of insertion of the airway device was noted: Ease was defined as no resistance to insertion of the airway device in a single maneuver, but, in a difficult insertion, there was resistance to insertion or more than one maneuver was needed for correct insertion.
- Insertion attempts were recorded. The insertion of the airway device was reported as successful after the first or the second attempt. However, failure of insertion at the second attempt was reported as failure and the patient was excluded from the study.
- The ease, the difficulty, and failure of gastric tube insertion were also recorded; failure was defined as the failure of insertion of the gastric tube after two attempts.
- The leak volume was calculated as the difference between the inspired and the expired tidal volumes; these volumes were recorded 3 min after the insertion of the devices using the integral spirometer in the anesthetic machine (Datex-Ohmeda Inc., Madison, Wisconsin, USA).
- The airway sealing pressure was determined by closing the expiratory valve of the circuit system at a fixed gas flow of 3 l/min, stopping ventilation, keeping the patient apneic, and recording the airway pressure at which equilibrium was achieved. At this time, air leak can be detected at the mouth by hearing an audible noise coming from the mouth or by putting a stethoscope just lateral to the thyroid cartilage  .
- The mean arterial blood pressure (MAP), the heart rate (HR), and oxygen saturation were recorded before induction (T1), after induction (T2), and after insertion of the airway device (T3).
- End-tidal carbon dioxide was recorded only after the insertion of the airway device and the gastric tube.
- Postoperative airway complications, including blood on the device, bronchospasm, laryngospasm, hoarseness, regurge, dysphagia, tongue, lip, and dental trauma, nausea and vomiting, were evaluated in the recovery room and 24 h postoperatively.
The insertion time was 9.63 ± 2.23 min in the I-gel group, whereas in the PLMA group, it was 11.73 ± 2.5 min at 80% power and 95% confidence interval. The estimated sample was 20 patients in each group (open Epi).
Data were checked, entered, and analyzed using SPSS version 20 (IBM Corp. Armonk, NY). Data were expressed as mean ± SD for quantitative variables, and number and percentage for categorical variables. The c2 -test and the analysis of variance (F test) tests were used when appropriate. P value less than 0.05 was considered statistically significant.
| Results|| |
There were no significant differences between the three groups with respect to demographic data and the duration of surgery (P > 0.05) [Table 1]. The mean insertion time of the I-gel group (9.8 ± 2.5 s) was found to be significantly lower than that of the PLMA group (15.4 ± 3.2 s) and of the ETT group (14.1 ± 2.1 s) (P < 0.001) [Table 2]. The I-gel group (19/20) and the ETT group (18/20) showed a significantly easier insertion compared with the PLMA group (13/20) (P < 0.05) [Table 2].
|Table 2 Comparison of the insertion time, the ease of insertion, insertion attempts, and the ease of gastric tube insertion between the three groups|
Click here to view
In all patients, the I-gel, the PLMA, and the ETT were inserted within two attempts with no significant differences between the three group (P = 0.57) [Table 2]. The success of insertion of the airway device after the first attempt was recorded in 19 , 17, and 18 patients in the I-gel group, the PLMA group and the ETT group, respectively. The second attempt rate was 1/20 for the I-gel group, 3/20 for the PLMA group, and 2/20 for the ETT group [Table 2]. The ease of gastric tube insertion in the I-gel group (18/20) and the ETT group (19/20) was better than in the PLMA group (16/20), but the difference was statistically nonsignificant (P > 0.05) [Table 2]. Tidal volumes (inspired and expired) and leak volumes were comparable between the three groups. They were 540 ± 85, 505 ± 79, and 35 ± 22 ml for the I-gel group, respectively, 539 ± 82, 510 ± 75, and 29 ± 18 ml for the PLMA group, respectively, and 542 ± 84, 514 ± 73, and 28 ± 16 ml for the ETT group, respectively (P > 0.05) [Table 3]. The mean value of the airway sealing pressure was found to be lower in the I-gel group (24.8 ± 5.8 mmHg) than in the PLMA group (27.33 ± 6.5 mmHg) and in the ETT group (28.5 ± 5.7 mmHg), but statistically nonsignificant (P > 0.05) [Table 3].
|Table 3 Comparison of the inspired tidal volume, the expired tidal volume, the leak volume, and the airway sealing pressure between the three groups|
Click here to view
There were no significant differences between the three groups regarding the MAP and the HR before and after the induction of anesthesia (P > 0.05) [Table 4]. The MAP in the ETT group (110 ± 13 mmHg) was significantly increased after insertion (T3) when compared with the I-gel group (100 ± 10 mmHg) and the PLMA group (102 ± 11 mmHg) (P < 0.05) [Table 4].
|Table 4 Changes in the mean arterial blood pressure, heart rate, oxygen saturation, and end-tidal carbon dioxide at different times|
Click here to view
When comparing the changes of MAP before the induction (T1) and after the insertion of airway devices (T3) in each group, we found no significant differences in the I-gel and the PLMA groups (P>0.05), but there was a significant increase in MAP after the insertion (T3) in the ETT group (110 ± 13 mmHg) when compared with the preinduction of anesthesia (T1) (102 ± 10 mmHg) (P < 0.05) [Table 4].
In contrast, there were no significant changes in the HR after the insertion of the airway devices between the three groups (P > 0.05) [Table 4].
Other parameters such as oxygen saturation and end-tidal carbon dioxide were comparable between the three groups (P > 0.05) [Table 4].
Regarding the occurrence of postoperative complications such as blood on the device, bronchospasm, laryngospasm, and tongue, lip, or dental trauma, there were no significant differences between the three groups (P > 0.05) [Table 5]. In contrast, in the I-gel and the PLMA groups there was a significantly lower incidence of other postoperative airway complications such as hoarseness (P < 0.05), regurge (P < 0.01), dysphagia (P < 0.001), nausea (P < 0.05), and vomiting (P < 0. 01) when compared with the ETT group [Table 5].
| Discussion|| |
SGA devices widely introduce a major change in the anesthesia practice and airway management. It can be used as an alternative to tracheal intubation for elective short procedures requiring general anesthesia during spontaneous or controlled ventilation  .
SGA devices have a lot of advantages over ETT such as a low stress response for insertion, they do not require laryngoscopy or muscle relaxation for insertion, provide rapid access to the airway, and allow safe airway for spontaneous or controlled ventilation , .
The main difference between the I-gel and the other SGA devices is the absence of the inflatable cuff as it is made of a gel-like material, and so it provides a seal in patients with a wide range of anatomical variations  . Results of this study showed that the I-gel group had a significantly lower mean insertion time (9.8 ± 2.5 s) than the other two groups.
Chauhan et al.  reported that the mean insertion time in the I-gel group was significantly lower than in the PLMA group. In another study, a mean insertion time of 11 s was recorded with I-gel  .
In this study, both the I-gel and the ETT groups were significantly easy to be inserted when compared with the PLMA group.
Singh et al.  reported that the insertion of I-gel was much easier than with PLMA. Other studies concluded that I-gel had a lower insertion time and the ease of insertion was slightly better when compared with the LMA unique , .
I-gel was inserted rapidly and easily in both patients and manikins ,, . In contrast to this study, Weber et al.  reported that insertion difficulty and insertion attempts were higher in the I-gel group when compared with the LMA-unique group. They explained their results by the larger size of I-gel and its thicker proximal end with an integral bite block when compared with the size of LMA-unique.
Another explanation for the insertion difficulty with I-gel is that the patients in their study had a Mallampati score of 3 or more, but in the present study, the patients had a Mallampati score of 1 or 2 only. There were no significant differences between the three groups regarding the success rate of the first and the second insertion attempts.
In a study of Sharma et al.  , the success rate of the first insertion attempt was higher for the tracheal tube when compared with PLMA, but the difference was statistically nonsignificant.
In the present study, the ease of gastric tube insertion in the I-gel group and the ETT group was better than in the PLMA group, but the difference was statistically nonsignificant.
This result was in accordance with the result of Singh et al.  , who reported that the ease of gastric tube insertion was better in the I-gel group (30/30) than with PLMA (26/30), but the difference was statistically nonsignificant. However, Chauhan et al.  demonstrated that the ease of gastric tube insertion was significantly higher in the I-gel group (easy = 95%) when compared with PLMA (easy = 72.5%). Also, Siddiqui et al.  found that the gastric tube insertion was very easy in all patients within the I-gel group.
Leak volumes in this study were comparable between the three groups. In a cross-over trial for Uppal et al.  , the leak volume with ETT was similar to that with I-gel during PCV. The same results were reported by Uppal et al.  when I-gel was compared with LMA-unique during PCV. The similarity of the leak volumes between the three groups made the I-gel group to be better in producing a good seal compared with the other two groups. I-gel fit well onto the perilaryngeal tissue without an inflatable cuff, but the other devices depend on the inflatable cuff. Overinflation of the cuff applied excessive pressure on the mucosa, whereas underinflation caused gas leak and inadequate ventilation , . However, Teoh et al.  reported that the I-gel had a significantly higher leak volume when compared with LMA supreme. They attributed these results to the use of noninflatable cuff and the gel-like material of the I-gel, which made it more liable to airway leaks, especially if the wrong size was chosen.
The mean airway sealing pressure in this study was found to be lower in the I-gel group (24.8 ± 5.8 cmH 2 O) than in the PLMA group (27.33 ± 6.5 cmH 2 O) and the ETT group (28.5 ± 5.7 cmH 2 O), but the difference was statistically nonsignificant. The absence of the inflatable cuff with the I-gel group made it more susceptible to more airway leak during PCV  . The airway sealing pressure in this study was within normal limits.
This result was similar to those from Uppal et al.  , who demonstrated no significant difference in the airway leak pressure when comparing I-gel with the cuffed ETT during PCV.
Also, a study of Singh et al.  was in close approximation to the results of this study as the average airway sealing pressure was 25.27 cmH 2 O for the I-gel group and 29.6 for PLMA. Of note, Chauhan et al.  reported that there was a significant lower-airway sealing pressure in the I-gel group (26.73 ± 2.52 cmH 2 O) in comparison with the PLMA (29.55 ± 5.3 cmH 2 O).
However, other studies comparing I-gel with LMA-unique or the classic LMA showed a higher airway leak pressure with I-gel than with the other airway devices , . These studies render the improved seal to the thermoplastic elastomer material of the I-gel, which is modeled anatomically to fit the perilaryngeal and the hypopharingeal structures without an inflatable cuff.
After the insertion of the airway device, the ETT group had a significantly higher MAP (110 ± 13 mmHg) when compared with the I-gel group (100 ± 10 mmHg) and the PLMA group (102 ± 11 mHg) (P < 0.05).
On comparison between the preinduction period (T1) and after airway device insertion (T3) in each group, the MAP showed no significant changes in the I-gel and the PLMA groups (P>0.05), but in the ETT group there was a higher significant increase after insertion (P < 0.05).
Similar studies comparing SGA devices with ETT showed less hemodynamic changes during induction and maintenance of anesthesia with SGA devices than with ETT , . Also, these results were in agreement with the results of Uppal et al.  , who concluded that there were less hemodynamic changes with I-gel in comparison with ETT using PCV.
In this study, a comparison between the I-gel and the PLMA groups regarding the hemodynamic changes showed no significant differences (P > 0.05). This result is in a close approximation with the results of Chauhan et al.  .
Postoperative airway complications in this study were significantly more in the ETT group than in the other two groups. These results were in agreement with the results of Uppal et al.  , who reported less postoperative airway complications with I-gel when compared with ETT. Also, other studies comparing ETT with SGA devices concluded that postoperative airway complications and hemodynamic changes were more with ETT than with SGA devices ,, .
The inflatable cuff is the main reason for the increased incidence of postoperative airway complications in the ETT group. It causes tissue distortion, venous compression, and nerve injury  .
In contrast, when comparing postoperative airway complications in the I-gel group with the PLMA group, there was no significant difference. This result was similar to Singh et al.  when comparing I-gel with PLMA.
However, Chauhan et al.  demonstrated a higher incidence of some complications such as blood staining of the device, sore throat, and dysphagia in the PLMA group when compared with the I-gel group, but other complications such as bronchospasm, laryngospasm, aspiration, regurgitation, and hoarseness were comparable between the two groups.
This study had some limitations
The first limitation was that the sample size was relatively small and it included only low-risk patients (ASA I or II) who had a normal airway and were not obese.
The second limitation was that we did not use fibreoptic bronchoscopy to detect the anatomical position of the airway devices in relation to the vocal cord as the anatomical finding does not necessarily correlate with the clinical consequences  .
Finally, the present study did not include patients with a full stomach to examine the performance of I-gel in this situation.
| Conclusion|| |
This study concluded that I-gel is a good alternative device to PLMA and ETT during minor elective surgery using controlled ventilation as it produces minimal hemodynamic changes and less airway morbidity. In addition, it was rapid and easy to insert.
Financial support and sponsorship
- Attempts should be made using a large sample size.
- Studies should be conducted on patients having a Mallampati III, IV to detect the clinical performance of I-gel in difficult airway situations.
- Manufacturers must reduce the size of I-gel to be suitable in difficult airway management.
- Using I-gel in challenging situations such as laparoscopic surgeries and in hemodynamically unstable patients may be promising.
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]