INTRODUCTION
One of the primary responsibilities of every anaesthesiologist is to
maintain patent airway. The most definitive method of securing airway in
children remains intubation of trachea.
Paediatric patients have specific airway characteristics that are
rather different from those of adults, and their intubation therefore has a
number of unique features. This age group is more commonly associated
with higher rates of complications of laryngoscopy and intubation.
Supraglottic airway devices have been shown to be safe &
effective in paediatric anaesthesia. It has many advantages over
endotracheal tube by producing less sympathetic stimulation, less airway
irritability and they are well tolerated at lighter plane of anaesthesia.
Due to its large calibre, supraglottic airway devices produce less airway
resistance compared to an endotracheal tube and decreased work of
breathing during spontaneous ventilation under anaesthesia .
Laryngeal mask airway, a supraglottic airway device is designed to
provide and maintain a seal around the laryngeal inlet that could
overcome the complications associated with endotracheal intubation.
The laryngeal mask airway provides a useful alternative to the tracheal
tube when it is necessary to administer anaesthesia to children with an
upper respiratory infection. However, classic LMA widely used in
paediatric anaesthesia has many limitations like, less stability after
insertion and does not contain drainage tube.
The relatively new supraglottic airway devices, LMA-Proseal & IGel
have been introduced recently and are safely used in children
during spontaneous or controlled ventilation without complications.
LMA-ProSeal is a specialized laryngeal mask device that has an
integral bite block. It has two cuffs. The cuff design is modified to
improve the seal with the larynx, which allows ventilation at much higher
airway pressures. In the smaller paediatric sizes, there is no second
dorsal cuff but mask profile has been modified to improve the seal.
LMA-Proseal has an oesophageal drainage tube, placed lateral to the
main airway tube which reduces the risk of gastric insufflations and
pulmonary aspiration.23 Monitoring devices, Doppler probe, and
medications can be passed into the oesophagus through the oesophageal
drain tube.
I-Gel a novel supraglottic airway device with a non-inflatable cuff,
is composed of transparent, soft gel like, thermoplastic elastomer. The
shape and contour of the cuff accurately mirrors the peri-laryngeal
structures to attain a perfect seal. Airway seal tend to improve with time
likely due to the warming of the thermoplastic cuff to body temperature.
Due to its stability, the I-Gel device allows the child to be placed in the
lateral decubitus position to perform caudal anaesthesia, without causing
a leak or the displacement of the supraglottic device. Since I-Gel can be
used in spontaneously breathing patients, it also has gastric channel and
posses greater stability, it is a useful device for MRI suite in children. IGel
has been used as a rescue device in difficult, failed intubation
situation and resuscitation.
Although it has all the advantages and more stability, there are
very few controlled randomized studies comparing I-Gel with LMAProseal
in children.
We chose the I-Gel supra glottic airway device in comparison with
the LMA-Proseal because both devices attain an effective airway seal
associated with higher oropharyngeal seal pressures and both have
gastric channel for the drainage of gastric contents.
Therefore, a prospective randomized single blind study was
designed and the I-Gel was compared with LMA-Proseal with respect to
ease of insertion, number of insertion attempts, insertion time,
oropharyngeal leak pressure, and possible complications in paediatric
elective surgeries under general anaesthesia.
AIM OF THE STUDY:
The aim of this study is to compare the clinical performance of IGel and LMA -Proseal in anaesthetized, spontaneously breathing, paediatric age group patients posted for elective, below umbilical surgical procedures. The following parameters are compared between two devices,
1. Ease of insertion,
2. Success rate to place at first attempt,
3. Number of insertion attempts,
4. Time taken for device insertion,
5. Airway seal pressure,
6. Ease of gastric tube placement,
7. Occurrence of complications like bronchospasm, aspiration, cough, hoarseness, blood staining of the device, mucosal/ lip trauma.
METHODOLOGY:
Study design:
Our study was a single blinded, randomized comparative study
conducted in Government Stanley medical college hospital, Chennai
during the period of October 2011 to September 2012.
Study setting and population:
After obtaining the approval from the institutional ethical
committee of the Stanley Medical College, a pilot study was done to
define the study population and decide on inclusion and exclusion
criteria. A target population of 100 patients was decided. The parents
were explained about the purpose of the study, the procedure, and the
intended study methods. An informed consent was obtained.
Criteria for selection:
Inclusion Criteria:
1. ASA PS I and ASA PS II,
2. Child of age 2 to 8 years,
3. Patients of either sex,
4. Weight of 10 to 25 kgs,
5. Mouth opening of more than 3 cm,
6. Elective surgeries of duration up to 60 minutes, such as
Herniotomy, Circumcision, Orchidopexy, Vesicolithotomy,
Hydrocele.
Exclusion Criteria:
1. Restricted mouth opening,
2. Altered airway anatomy,
3. Congenital heart disease,
4. Emergency surgeries,
5. Risk of aspiration,
6. Bleeding disorders.
Relative contraindication would be a child with an uncontrolled
respiratory tract infection.
The selected children were randomized into one of two groups
labelled as I and P by allotting lots with alphabets I and P. Children with
lot I were assigned to group I. Those with lot P were assigned to group P.
Each group was allotted with 50 children.
All children were fasted six hours pre-operatively for solids and 2
hours for clear fluids. The patients were brought into the operation theatre
and intravenous access obtained with appropriate size venous cannula.
Intravenous fluid Ringer’s lactate was started. Standard monitors like
Pulse Oximeter, Automated Non-invasive Blood Pressure, ECG,
Precardial stethoscope were connected and baseline values were
recorded. All patients were premedicated with Inj. Atropine 20 μg / kg
I.V, Inj.Midazolam 0.02 mg / kg I.V, Inj.Fentanyl 2 µg/kg I.V, and
Inj.Ondansetron 0.1 mg/kg I.V, 5 min prior to induction of anaesthesia.
Preoxygenation was done with 100% oxygen for 3 minutes. Induction
was achieved with Inj.Propofol 3 mg/kg I.V mixed with Inj. Lignocaine
0.5 mg/kg. Facemask ventilation was done with 2% to 3% Sevoflurane
and oxygen until optimal conditions for supraglottic device insertion were
attained.
SUMMARY:
The aim of this study is to compare the clinical performance of IGel and LMA- Proseal in anaesthetized, spontaneously breathing, paediatric age group patients posted for elective, below umbilical surgical procedures. This a prospective single blind randomized comparative study.
After obtaining Institutional Ethical committee approval, hundred paediatric patients of ASA physical status I and II of either sex were included in the study. Patients were randomly assigned into two groups, Group P: LMA-Proseal (n=50) and Group I: I-Gel (n=50). The technique of anaesthesia was standardised in both the groups. The following parameters were compared.
1. Ease of insertion,
2. Success rate to place at first attempt,
3. Number of insertion attempts,
4. Time taken for device insertion,
5. Airway seal pressure,
6. Ease of gastric tube placement,
7. Occurrence of complications like bronchospasm, aspiration, cough, hoarseness, blood staining of the device, mucosal/ lip trauma.
Both groups were comparable in demographic characteristics. The mean insertion time for I-Gel was significantly less than LMA-Proseal (p0.001). The oropharyngeal seal pressure of I-Gel was significantly less when compared with LMA-Proseal (p0.0001). There was no statistical difference between the two groups in regards with number of attempts required for the placement of the supraglottic airway device and ease of insertion of gastric tube. Complications like cough, hoarseness, blood stained device were high in LMA-Proseal group. I-Gel aids easy and rapid insertion with an acceptable airway seal pressure. However, effective airway seal pressure with LMA-Proseal is better than I-Gel.
CONCLUSION:
Based on the results of our study, we conclude that I-Gel aids easy and rapid insertion with an acceptable airway seal pressure. I-Gel scores well than LMA- Proseal in terms of lesser insertion time and lesser incidence of postoperative complications due to its noninflattable cuff and facilitate effective gastric drainage. However, effective airway seal pressure with LMA-Proseal is better than I-Gel. Both devices can be safely used in anaesthetized spontaneously ventilating children for short surgical procedures.