Comparison of Clinical Performance of Supraglottic Airway Devices I-GEL Vs LMA-Proseal in Paediatric Elective Surgeries

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