Comparative study between I-gel, a new supraglottic airway device, and classical laryngeal mask airway in anesthetized spontaneously ventilated patients

Abstract

To compare two different supraglottic airway devices, the laryngeal mask airway (LMA) and the I-gel, regarding easiness of insertion of the device, leak pressure, gastric insufflation, end tidal CO(2), oxygen saturation, hemodynamic and postoperative complications in anesthetized, spontaneously ventilated adult patients performing different non-emergency surgical procedures.
The study was carried out as a prospective, randomized, clinical trial among 80 patients who underwent different surgical procedures under general anesthesia with spontaneous ventilation in supine position. They were equally randomized into two groups: I-gel and LMA groups. Both the devices were compared with regard to heart rate, arterial BP, SPO(2), end-tidal CO(2), number and duration of insertion attempts, incidence of gastric insufflation, leak pressure and airway assessment after removal of the device.
No statistically significant difference was reported between both the groups, regarding heart rate, arterial BP, SPO(2) and end-tidal CO(2). The mean duration of insertion attempts was 15.6±4.9 seconds in the I-gel group, while it was 26.2±17.7 seconds in the LMA group. The difference between both the groups regarding duration of insertion attempts was statistically significant (P=0.0023*), while the number of insertion attempts was statistically insignificant between both the study groups (P>0.05). Leak pressure was (25.6±4.9 vs. 21.2±7.7 cm H(2)O) significantly higher among studied patients of the I-gel group (P=0.016*) and the incidence of gastric insufflation was significantly more with LMA group 9 (22.5%) vs. I-gel group (5%) (P=0.016).
Both LMA and I-gel do not cause any significant alteration in the hemodynamic status of the patients, end tidal CO(2), and SPO(2). The postoperative complications were not significantly different except nusea and vomiting was statistically significant higher in LMA group (P=0.032). among both LMA and I-gel patients. Insertion of I-gel was significantly easier and more rapid than insertion of LMA. Leak pressure was significantly higher with I-gel than LMA and thus incidence of gastric insufflation was significantly lower with I-gel.

Full text

583 M.E.J. ANESTH 21 (4), 2012
COMPARATIVE STUDY BETWEEN I-GEL,
A NEW SUPRAGLOTTIC AIRWAY DEVICE,
AND CLASSICAL LARYNGEAL MASK
AIRWAY IN ANESTHETIZED SPONTANEOUSLY
VENTILATED PATIENTS
Hossam m. atef**, amr m. Helmy*,
ezzat m. el-taHer* and aHmed mosaad Henidak*
Abstract
Objective: To compare two different supraglottic airway devices, the laryngeal mask airway
(LMA) and the I-gel, regarding easiness of insertion of the device, leak pressure, gastric insufation,
end tidal CO2, oxygen saturation, hemodynamic and postoperative complications in anesthetized,
spontaneously ventilated adult patients performing different non-emergency surgical procedures.
Materials and Methods: The study was carried out as a prospective, randomized, clinical trial
among 80 patients who underwent different surgical procedures under general anesthesia with
spontaneous ventilation in supine position. They were equally randomized into two groups: I-gel
and LMA groups. Both the devices were compared with regard to heart rate, arterial BP, SPO2,
end-tidal CO2, number and duration of insertion attempts, incidence of gastric insufation, leak
pressure and airway assessment after removal of the device.
Results: No statistically signicant difference was reported between both the groups,
regarding heart rate, arterial BP, SPO2 and end-tidal CO2. The mean duration of insertion attempts
was 15.6 ± 4.9 seconds in the I-gel group, while it was 26.2 ± 17.7 seconds in the LMA group.
The difference between both the groups regarding duration of insertion attempts was statistically
signicant (P 0.0023*), while the number of insertion attempts was statistically insignicant
between both the study groups (P >0.05). Leak pressure was(25.6 ± 4.9 versus 21.2 ± 7.7 0.016*
cmH2O) signicantly higher among studied patients of the I-gel group and incidence of gastric
insufation was signicantly more with LMA 9 (22.5%) versus 2 (5%) 0.016* in I-gel group.
Conclusion: Both LMA and I-gel do not cause any signicant alteration in the hemodynamic
status of the patients, end tidal CO2, and SPO2. The postoperative complications were not signicantly
different except nusea and vomiting was statistically signicant higher in LMAgroup(P 0 .032).
among both LMA and I-gel patients. Insertion of I-gel was signicantly easier and more rapid than
insertion of LMA. Leak pressure was signicantly higher with I-gel than LMA and thus incidence
of gastric insufation was signicantly lower with I-gel.
Key words: Classical laryngeal mask airway, I-gel, supraglottic airway devices
* Department of Anesthesia and Intensive Care, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.
Corresponding author: Hosam Atef, Department of Anesthesia and Intensive Care, Faculty of Medicine, Suez Canal
University, Ismailia, Egypt, Email: hosamatef375@yahoo.com

584 H. M. ATEF ET AL.
Introduction
The major responsibility of the anesthesiologist
is to provide adequate ventilation to the patient. The
most vital element in providing functional respiration
is the airway. Management of the airway has come
a long way since the development of endotracheal
intubation by Macewen in 1880 to the present day
usage of sophisticated devices1. The tracheal intubation
is the gold standard method for maintaining a patent
airway during anesthesia2. However, this maneuver
requires skill and continuous training and practice and
usually requires direct laryngoscopy, which may cause
laryngopharyngeal lesions3.
Laryngoscopy and endotracheal intubation
produce reex sympathetic stimulation and are
associated with raised levels of plasma catecholamines,
hypertension, tachycardia, myocardial ischemia,
depression of myocardial contractility, ventricular
arrhythmias and intracranial hypertension4. The wide
variety of airway devices available today may broadly
be classied as intraglottic and extraglottic airway
devices, which are employed to protect the airway in
both elective as well as emergency situations5.
The laryngeal mask airway (LMA; Laryngeal
Mask Company, Henley-on-Thames, UK) has been
well established for more than a decade and is often
used when endotracheal intubation is not necessarily
required6. Nevertheless, simple handling of the LMA
is limited by the potential risk of aspiration7 (because
beroptic studies have found 6-9% visualization
of the esophagus via the LMA)8,9 or low pulmonary
compliance [(e.g. obesity) requiring peak inspiratory
pressures greater than 20 cm H2O]10.
I-gel is the single use supraglottic airway from
intersurgical, UK (Intersurgical Ltd, Wokingham,
Berkshire, UK) with an anatomically designed mask
made of a gel like thermoplastic elastomer. It has
features designed to separate the gastrointestinal
and respiratory tracts and allow a gastric tube to be
passed into the stomach4. The tensile properties of the
I-gel bowl, along with its shape and the ridge at its
proximal end, contribute to the stability of the device
upon insertion. Upon sliding beneath the pharyngo-
epiglottic folds, it becomes narrower and longer,
creating an outward force against the tissues. The ridge
at the proximal bowl catches the base of the tongue,
also keeping the device from moving upward out of
position (and the tip from moving out of the upper
esophagus)11.
The main aim of this study was to compare the
I-gel with the LMA in terms of the success of insertion
of the device, gas leak pressure, the incidence of
gastric insufations and postoperative device related
complications.
Materials and Methods
Subjects
This study was carried out as a prospective,
randomized, clinical trial. After getting approval
from our ethics committee, 80 patients aged 21-60
years, of both sexes, who underwent different surgical
procedures under general anesthesia with spontaneous
ventilation in supine position for not more than 2 hours
in routine surgical theaters in Suez Canal University
Hospital in Ismailia city, were enrolled based on
certain inclusion and exclusion criteria. Inclusion
criteria included the following: (i) patients of ASA
I or ASA II and (ii) patients whose body mass index
(BMI) was 20-25 kg/m2. Patients with reported history
of hypersensitivity for one or more of the medications
and latex, patients having any abnormality of the
neck, upper respiratory tract, patients with history of
obstructive sleep apnea or patients who underwent
thoracic, abdominal and neurosurgery operations were
excluded. The patients were equally randomized into
two groups: group 1 (I-gel group) and group 2 (LMA
group).
Methods
Preoperative assessment and medication
Complete medical history and physical
examination were done for all patients, including
assessment of vital signs and airway assessment. After
arrival in the pre-anesthetic area, the patients were given
2 mg midazolam intravenously (IV) as premedication,
and then 10 mg Metoclopramide IV was also given 3
minutes before induction of anesthesia Preoxygenation
for 3minutes, and anesthesia was induced with fentanyl
1mic/kg, and propofol 2mg/kg.

M.E.J. ANESTH 21 (4), 2012
585
COMPARATIVE STUDY BETWEEN I-GEL, A NEW SUPRAGLOTTIC AIRWAY DEVICE, AND CLASSICAL
LARYNGEAL MASK AIRWAY IN ANESTHETIZED SPONTANEOUSLY VENTILATED PATIENTS
Device insertion
After an adequate depth of anesthesia had been
achieved, each device was inserted by the same senior
anesthetist (A H). In group 1, the classical LMA was
inserted according to the manufacturer’s instruction
manual. A size 3 and 4 mask was used in females
and a size 4 and 5 mask in males. The LMA cuff was
inated with 20ml; 30ml; 40ml of air for size 3; 4; 5
respectively as recommended by the manufacture12.
For patients of group 2, the I-gel size #3, 4
or 5 was inserted according to the manufacturer’s
instructions13.
In both the groups, if it was not possible to
ventilate the lungs, the following airway maneuvers
were allowed: chin lift, jaw thrust, head extension, or
exion on the neck. In the case of I-gel, the position
was also allowed to be adjusted by gently pushing or
pulling the device. After any maneuver, adequacy of
ventilation was re-assessed. This maneuver was used
with one patient in LMA group. If it was not possible
to insert the device or ventilate through it, two more
attempts at insertion were allowed. If placements had
failed after three attempts, the case was abandoned and
the airway maintained through other airway device
as suitable and this case was considered as a failed
attempt.
Maintenance of anesthesia
After securing the device, spontaneous ventilation
in oxygen, air and inhalational agent was started.
Ventilation was judged to be optimal if the following
four tests will be passed: (i) adequate chest movement;
(ii) stable oxygenation not less than 95%; (iii) “square
wave” capnography and (iv) normal range end tidal
CO2.
Removal of the device
At the end of the operation, anesthetic agents
were discontinued, allowing smooth recovery of
consciousness. The device was removed after the
patient regained consciousness spontaneously and
responded to verbal command to open the mouth.
Dysphagia, dysphonia, nausea, vomiting and trauma of
mouth, tooth or pharynx, and sore throat were recorded
and reassessed within 24 hours.
Parameters measured
Monitoring equipments (Datex-Ohmeda™) were
attached to the patient including 3 leads ECG and non-
invasive blood pressure pulse oximetry and manometer
was connected to the inspiratory limb of the breathing
system to measure the airway pressure. The following
parameters were measured.
1) Heart rate, non-invasive blood pressure, end-
tidal CO2 tension and oxygen saturation (SpO2).
2) The leak pressure by closing the expiratory
valve of the circle system at a xed low gas ow
(3L/min), observing the air-way pressure at which
equilibrium was reached. At this point, gas leakage
was heard at the mouth, at the epigastrium (epigastric
auscultation) or coming out the drainage tube (I-gel
group). manometric stability test is one of the most
reliable test14.
3) Number of insertion attempts and each attempt
duration (time from picking up the device until
attaching it to the breathing system in minutes).
4) Incidence of airway complications caused by
supraglottic devices.
= reporting of post-extubation cough, breath holding
or laryngeal spasm,
= observing presence of blood on the I-gel or LMA,
and
= lip and dental injury.
Each patient
was questioned to determine the
following complications (in recovery room and 24
hours postoperatively): sore
throat (constant pain,
independent of swallowing), dysphagia
(difculty or
pain with swallowing), sore jaw, dysphonia (difculty
or pain with speaking), numbness of the tongue or the
oropharynx,
blocked or painful ears, reduced hearing,
or neck pain. Primary outcome measures: number
and duration of insertion attempts,sealing pressure
and peak airway pressure. Secondary outcome
measures: postoperative airway complications.
Power analysis was based on Duration of insertion
attempts (sec.) with Standard deviation (s) 15.62 and
Variance (s
2
) 243.9.considering alpha (z
α
) error (p =
0.05; therefore, 95% condence desired (two-tailed

586 H. M. ATEF ET AL.
test); z
α
= 1.96) and beta (z
β
) error (20% beta error,
therefore, 80% power desired (one-tailed test); z
β
=
0.84). Difference to be detected (d) 10 sec. Or larger
difference between mean duration of the experimental
group and control group 39 patients were required in
each group.
Statistical Analysis
The Data was collected and entered into the
personal computer. Statistical analysis was done using
Statistical Package for Social Sciences (SPSS/version
17) software. A comparison of the overall abilities of
the two techniques to accurately classify the patients
was performed by a Z test to compare two portions.
Arthematic mean, standard deviation, number and
percent was calculated for each parameter. For
categorized parameters chi-square test was used, Fisher
exact test was used for data less than 5 in each cell,
while for numerical data t-test was used to compare
two groups. The level of signicant was 0.0515.
Results
Analysis of the demographic characteristics of
our patients under study has revealed that there was
no statistically signicant difference when comparing
the mean age between the two groups (P >0.05). The
same was found regarding the distribution of sex, as
no statistically signicant difference was found when
comparing the two groups. Most of the patients in the
groups of the study were found to be males (60 and 70%
in I-gel and LMA groups, respectively). There was no
statistically signicant difference found in BMI between
the two groups of the study (P >0.05) (Table 1).
Table 1
Personal characteristics of the patients under study
Characteristic I-gel group
(n = 40)
LMA group
(n = 40)
Age 38.29 ± 12.4 41.62 ± 13.4
Gender Male 24 (60%) 28 (70%)
Female 16 (40%) 12 (30%)
BMI (kg/m2) 23.13 ± 2.15 22.91 ± 4.03
Data are presented as mean ± SD or numbers (percentages)
NS: no statistically signicant difference (P >0.05)
No statistically signicant difference was found
between both groups of the study, regarding each of
systolic BP, diastolic BP, heart rate, SPO2 (%) and end-
tidal CO2 throughout the whole duration of the surgery.
Table 2 shows that insertion and ventilation was
possible at the rst attempt in 90% of patients in the
I-gel group and in 80% in LMA group. In 5% of the
patients in LMA group, intubation and ventilation was
possible after the third attempt. The mean duration of
insertion attempts was 15.62 ± 4.9 seconds in I-gel
group, while it was 26.2 ± 17.7 seconds in LMA group.
The difference between both groups regarding duration
of insertion attempts was statistically signicant (P
0.0023), while the number of insertion attempts was
statistically insignicant between both the study
groups (P >0.05). Leak pressure was signicantly
higher among patients of the I-gel group (25.62 ± 4.9
Table 2
Comparison between I-gel and LMA groups with respect to different parameters
Parameter I-gel group (n = 40) LMA group (n = 40) P value
Number of insertion attempts One attempt 36 (90%) 32 (80%)
0.45 (NS)
Two attempts 3 (7.5%) 6 (15%)
Three attempts 1 (2.5%) 2 (5%)
Duration of insertion attempts (seconds) 15.62 ± 4.9 26.2 ± 17.7 0.0023*
Leak pressure (cm H2O) 25.62 ± 4.9 21.2 ± 7.7 0.016*
Incidence of gastric insufation 2 (5%) 9 (22.5%) 0.016*
Data are presented as mean ± SD or numbers (percentages)
NS: no statistically signicant difference (P >0.05)
*Statistically signicant difference (P <0.05)

M.E.J. ANESTH 21 (4), 2012
587
COMPARATIVE STUDY BETWEEN I-GEL, A NEW SUPRAGLOTTIC AIRWAY DEVICE, AND CLASSICAL
LARYNGEAL MASK AIRWAY IN ANESTHETIZED SPONTANEOUSLY VENTILATED PATIENTS
versus 21.2 ± 7.7 cm H2O in LMA group; P <0.016).
The incidence of gastric insufation was signicantly
more with LMA (22.5% versus 5% in I-gel group; P
<0.016).
No statistically signicant difference was found
between both I-gel and LMA groups with regard to
the assessment of patients after removal of the airway
device (Table 3).
Success rate of gastric tube insertion was
estimated to be 95%. Failed insertion was reported
only among two patients (5%) (Table 4).
Table 4
Success rate of gastric tube insertion among the patients of
I-gel group
Number Percent
Gastric tube insertion
Success 38 95
Failure 2 5
Total 40 100
Discussion
The I-gel is a new supraglottic device, without an
inatable cuff, designed for use during anaesthesia11.
It is a latex free, disposable device, made of a medical
grade thermoplastic elastomer. I-gel is anatomically
preformed to mirror the perilaryngeal structures. The
device contains an epiglottis blocker, which helps to
prevent epiglottis from downfolding or obstructing
laryngeal inlet. The soft non-inatable cuff seals
anatomically against perilaryngeal structures.
Furthermore, the I-gel has a gastric channel allowing
venting of the air and gastric contents or insertion of
gastric tube16.
It has features designed to separate the
gastrointestinal and respiratory tracts and allow a
gastric tube to be passed into the stomach. Early
reports have postulated its use as a potential airway for
use in resuscitation17. Many studies compared LMA
with I-gel18-20.
Regarding the hemodynamic stability and effect
of each of the supraglottic devices, no statistically
signicant difference was reported when comparing
heart rate, systolic and diastolic arterial blood pressure
throughout the surgery. Jindal et al.21 reported
hemodynamic stability with both LMA and I-gel
devices, with no statistically signicant difference
between both devices, which is consistent with our
ndings.
Richez et al.13 carried out one of the earliest
Table 3
Assessment of patients after device removal among the patients in both groups of the study
I-gel group (n = 40) LMA group (n = 40) P value
Presence of blood on airway device 2 (5%) 4 (10%) 0.46 (NS)
Lip or dental injury 1 (2.5%) 2 (5%) 0.69 (NS)
Post removal cough 2 (5%) 6 (15%) 0.6 (NS)
Laryngeal spasm 4 (10%) 4 (10%) 1 (NS)
Sore throat Mild 12 (32.5%) 10 (25%) 0.34 (NS)
Moderate 3 (7.5%) 5 (12.5%)
Dysphagia, dysphonia 2 (5%) 2 (5%) 1 (NS)
Postoperative nausea or vomiting 2 (5%) 8 (20%) 0.032*
Arrhythmia 2 (5%) 3 (7.5%) 0.69 (NS)
Pain on swallowing Mild 21 (52.5%) 26 (65%) 0.47 (NS)
Moderate 4 (10%) 8 (20%)
Ear pain 3 (7.5%) 5 (12.5%) 0.46 (NS)
Hearing change 1 (2.5%) 2 (5%) 0.69 (NS)
NS: no statistically signicant difference (P > 0.05)

588 H. M. ATEF ET AL.
studies to evaluate the I-gel. They found that insertion
success rate was 97%. Insertion was easy and was
performed at the rst attempt in every patient. I-gel
is easily and rapidly inserted, providing a reliable
airway in over 90% of cases. Acott22. assessed the
use of I-gel as an airway device during general
anesthesia. In accordance with our results, they
reported that a single insertion attempt was required
in the majority of patients and all the insertion times
recorded were less than 10 seconds. Similar results
were obtained in study done by Gatward et al.23, who
evaluated size 4 I-gel airway in 100 non-paralyzed
patients and found that rst insertion attempt was
successful in 86% of patients, the second attempt
in 11% of patients and the third attempt in 3% of
patients.
Levitan and Kinkle11 studied the positioning and
mechanics of this new device in 65 non-embalmed
cadavers with 73 endoscopies (eight had repeat
insertion), 16 neck dissections, and 6 neck radiographs.
A full view of the glottis (percentage of glottic opening
score 100%) occurred in 44/73 insertions, whereas only
3/73 insertions had epiglottis-only views. Including the
eight repeat insertions with a different size, a glottic
opening score of >50% was obtained in all 65 cadavers.
The mean percentage of glottic opening score for the
73 insertions was 82% (95% condence interval 75-
89%). In each of the neck dissections and radiographs,
the bowl of the device covered the laryngeal inlet.
They found that the I-gel effectively conformed to the
perilaryngeal anatomy despite the lack of an inatable
cuff and it consistently achieved proper positioning for
supraglottic ventilation.
The I-gel has potential advantages over other
supraglottic airways for use by non-anesthetists
during cardiopulmonary resuscitation. It has no cuff to
inate, making it simple to use. Its drain tube allows
access to the gastrointestinal tract and it is designed to
reduce the risk of gastric ination and regurgitation.
Simple airway maneuvers were required to assist in
the placement but all devices were placed within two
attempts24. These ndings are consistent with our
results.
One of the most important parameters to be
compared between both supraglottic devices was
postoperative complications. It was estimated
that difference between LMA and I-gel regarding
postoperative complications was not statistically
signicant except nausea and vomiting which was
signicantly higher in LMA due to high incidence of
gastric insufation. Consistent with our results, no
major complications associated with I-gel have been
described to date. Protection against aspiration is
probably comparable with LMA family (but certainly
not 100%). Minor complications reported include
sore throat, temporary hoarseness, sore tongue,
hyperesthesia of tongue13.
In the present study, only in two patients of the
I-gel group, blood was on the device after removal.
Acott22, did not report any case of blood on airway
device (I-gel). In accordance with our results, he found
that airway trauma during insertion of the I-gel was
minimal.
Leak pressure was found to be signicantly
higher among patients of I-gel group than in LMA
group (25.62 versus 21.2 cm H2O, respectively). This
denotes that I-gel has better sealing pressure and that
it ts well with the anatomy of supraglottic region.
Acott22 reported a leak pressure greater than 20 cm
H2O in all patients.
Assessment of success rate of gastric tube
insertion with I-gel was found to be 95%. This is
consistent with what has been reported by Richez
et al.13, as the gastric tube was inserted in 100% of
cases. This helps in preventing gastric insufation and
decreasing air leak and thus decreasing postoperative
nausea and vomiting.
A potential risk of the LMA is an incomplete mask
seal, causing gastric insufation or oropharyngeal air
leakage25. Inconsistent with our ndings; Schmidbauer
and colleagues26 concluded that both the ProSeal
LMA and classical LMA provided better seal of the
esophagus than the novel I-gel airway. Consistent with
our results, Weiler et al.6 had reported high incidence
of gastric insufation with the use of LMA.
There are some limitations of the present study.
Firstly, we studied only low risk patients (ASA I and
II) who had normal airways and were mostly not obese.
Secondly, we did not compare performance with the
likely competitors of the I-gel such as ProSeal LMA
and laryngeal tube.

M.E.J. ANESTH 21 (4), 2012
589
COMPARATIVE STUDY BETWEEN I-GEL, A NEW SUPRAGLOTTIC AIRWAY DEVICE, AND CLASSICAL
LARYNGEAL MASK AIRWAY IN ANESTHETIZED SPONTANEOUSLY VENTILATED PATIENTS
In conclusion, both LMA and I-gel do not
cause any signicant alteration in the hemodynamic
status of the patients, end tidal CO2, and SPO2. The
postoperative complications are not signicantly
different among both LMA and I-gel patients. Insertion
of I-gel is signicantly easier and more rapid than
insertion of LMA. Leak pressure is signicantly higher
with I-gel than with LMA and thus incidence of gastric
insufation is signicantly lower with I-gel.

590
for assessing airway sealing pressure with laryngeal mask airway in
adult patients. Br J Anaesth; 1999, 82:286-7.
15. Snedecor George W, CocHran William G: Statistical methods. 8th
ed. Iowa State University Press; 1989.
16. MicHalek P, Hodgkinson P, D onaldson W: Fibreoptic intubation
through an I-gel supraglottic airway in two patients with predicted
difcult airway and intellectual disability. Anesth Analg; 2008,
106:1501-4.
17. Soar J: The I-gel supraglottic airway and resuscitation-some initial
thoughts. Resuscitation; 2007, 74:197.
18. Francksen H, Renner JP, Hanss R, ScHolz J, Doerges V, Bein B: A
comparison of the i-gel™ with the LMA-Unique™ in non-paralysed
anaesthetised adult patients. Anaesthesia; 2009, 64:1118-24.
19. Janakiraman C, CHetHan DB, Wilkes AR, Stacey MR, Goodwin N:
A randomised crossover trial comparing the i-gel supraglottic airway
and classic laryngeal mask airway. Anaesthesia; 2009, 64:674-8.
20. Uppal V, G angaiaH S, FletcHer G, Kinsella J: Randomized
crossover comparison between the i-gel and the LMA-Unique in
anaesthetized, paralysed adults. BJA; 2009, 103:882-5.
21. Jindal P, Rizvi A, SHarma JP: Is I-gel a new revolution among
supraglottic airway devices? A comparative evaluation. Middle East
J Anesthesiol; 2009, 20:53-8.
22. Acott CJ: Extraglottic airway devices for use in diving medicine-
part 3: The i-gel. Diving Hyperbaric Med; 2008, 38:124-7.
23. Gatward JJ, Cook T, Seller C, Handel J: Evaluation of the size
4 i-gel airway in one hundred non-paralyzed patients. Anesthesia;
2008, 10:1365-9.
24. WHarton NM, Gibbison B, Gabbott DA, Haslam GM, Cook TM:
I-gel insertion by novices in manikins and patients. Anesthesia;
2008, 63:991-5.
25. Latorre F, Eberle B, Weiler N, Mienert R, Stanek A, Goedecke
R, et al: Laryngeal mask airway position and the risk of gastric
lnsufation. Anesth Analg; 1998, 86:867-71.
26. ScHmidbauer W, Berker S, Volk T, B oguscH G, Mager G, Kerner
T: Oesophageal seal of the novel supralaryngeal airway device I-gel
in comparison with the laryngeal mask airways classic and ProSeal
using a cadaver model. Br J Anesth; 2008, 10:1093.
H. M. ATEF ET AL.
References
1. James CD: Sir William Macewen and anaesthesia. Anaesthesia;
1974, 29:743-53.
2. The European Resuscitation Council (ERC) and the American Heart
Association (AHA) in collaboration with the International Liaison
Committee on Resuscitation (ILCOR): International Guidelines
2000 for Cardiopulmonary Resuscitation and Emergency Cardiac
Care. An International Consensus on Science. Resuscitation; 2000,
6:29-71.
3. Peppard SB, Dickens JH: Laryngeal injury following short-term
intubation. Ann Otol Rhinol Laryngol; 1983, 92:327-30.
4. Gal TJ: Airway management. In: Miller RD, editor. Textbook of
anesthesia, 6th ed. p. 1617-52. Philadelphia: Elsevier; 2005.
5. JayasHree S: Laryngeal mask airway and its variants. Indian J
Anaesth; 2005, 49:275-80.
6. Weiler N, Latorre F, Eberle B, Goedecke R, HeinricHs W:
Respiratory mechanics, gastric insufation pressure, and air leakage
of the laryngeal mask airway. Anesth Analg; 1997, 84:1025-8.
7. Barker P, Langton JA, MurpHy PJ, RowbotHam DJ: Regurgitation
of gastric contents during general anaesthesia using the laryngeal
mask airway. Br J Anaesth; 1992, 69:358-60.
8. Payne J: The use of the breoptic laryngoscope to conrm the
position of the laryngeal mask. Anaesthesia; 1989, 44:865.
9. Morgan EG, Maged MS: Airway management. In: Clinical
anesthesiology. 4th ed. p. 65. McGraw-Hill Companies; USA 2006.
10. Asai T, M urao K, SHingu K: Efcacy of the laryngeal tube during
intermittent positive pressure ventilation. Anaesthesia; 2000,
55:1099-102.
11. Levitan RM, Kinkle WC: Initial anatomic investigations of the
I-gel airway: A novel supraglottic airway without inatable cuff.
Anaesthesia; 2005, 60:1022-6.
12. Brain A, Denman WT, Goudsouzian NG: Laryngeal Mask Airway
Instruction Manual. San Diego, Calif: LMA North America Inc;
1999.
13. RicHez B, Saltel L, BancHereau F: A new single use supraglottic
device with a noninatable cuff and an esophageal vent: An
observational study of the I-gel. Anesth Analg; 2008, 106:1137-9.
14. Keller C, Brimacombe JR, Morris R: Comparison of four methods