Application of I-gel Laryngeal Mask Airway in Pediatric Patients
Condition: the Efficacy and Performance of the Pediatric I-gel Mask
Study type: Interventional

Summary: 
      Background The laryngeal mask airway (LMA) is a supraglottic airway device ,which is commonly
      used to manage children's airways, because it is typically easy to use and can avoid problems
      specific to tracheal intubation. Since the LMA was introduced into clinical practice in 1988
      , various types of LMAs have been developed, the safety and efficacy of which have been
      established in both adults and children.The paediatric i-gel is a relatively new and
      disposable supraglottic airway device for children, which is made of a soft gel-like
      elastomer with a non-inflatable cuff and a channel for gastric catheter placement . It does
      not require cuff inflation ,reducing the complications associated with compression trauma and
      high cuff pressure . Medical-grade thermoplastic elastomer creates a more intimate interface
      for interacting with supraglottic tissue. The usage of i-gel mask is more common in adults
      ,though a large scale study focusing on children is lacking.

      Objectives:

      To evaluate the efficacy and performance of the pediatric i-gel mask

      Methods:

      From November 2018 to March 2019, subjects are selected from patients who undergo elective
      surgery at Xi'an Children's Hospital, within the age of 0 to 108 months old, with an American
      Society of Anesthesiologists physical status I or II .They were assigned into four groups
      according to their weight. Four groups are : 2-5 kg (group 1#), 5.1-12.0 kg (group 1.5#),
      10-25kg (group 2#) 25-35kg(group 2.5#). The primary outcome is the clinical performance of
      the airways: the rate of insertion at first attempt,the ease of insertion,the insertion
      time,the oropharyngeal leak pressure(OLP),the fibreoptic view and the ease of gastric tube
      insertion. The secondary outcome is the frequency of other perioperative complications as
      listed in the detail information section.
    

Detailed description: 
      methods This is a prospective, randomized, parallel-group, single sample study ,which was
      approved by the Ethics Committee of Children's Hospital affiliated to Xi'an Jiaotong
      University.The experiment is expected to be completed between December 2018 and March 2019 in
      Xi'an children's Hospital, signed consent will be obtained from the parents or the guardian
      of the child participating in the study.The inclusion criteria are: children aged between 0
      to 108 months, Weighed between 2 to 35 kg,with an American Standards Association (ASA
      )physical status Ι or Ⅱ, who are scheduled for elective surgery shorter than four hours under
      general anesthesia . In addition,the operation of supraglottic airway devices needs to be
      seamless during perioperative period. Children with below condition will be excluded form the
      experiment:a suspected difficult airway, a history of upper respiratory tract infection two
      weeks before operation ,being at risk of aspiration (such as non-fasting status ,
      gastroesophageal reflux disease and hiatus hernia),lung diseases, limited head-neck
      movements, and those refusing to participate.The children with symptoms bradycardia and
      conduction block shown on EEG are also excluded from this experiment.The children were
      assigned into four groups based on their weights : size 1 for 2-5kg ,size 1.5 for 5-12 kg,
      size 2 for 10-25 kg, size 2.5 for 25-35 kg . The required device is prepared according to the
      child's weight and using the the manufacturer's guidelines . The children's group allocation
      were operated by a researcher who do not participate in post anesthesia care unit or outcome
      assessment. All children involved in the experiment, the children's parents, and the data
      analyzer are blind to the device used. In preparation for surgery,children are fasted 8h from
      solid food with fat content, 6h from semi-solid food and liquid food ,4h for breast milk and
      2 h for clear water .Premedication is provided about 20 minutes before entering the operating
      room, by which children receive intranasal dexmedetomidine 1.5ug/kg, so that children can
      enter the operating room quietly. On arrival in the operating room, children were monitored
      using pulse oximetry, electrocardiography, non-invasive blood pressure, and capnography.
      General anaesthesia was induced with 100% oxygen 2-4 Liter(L)/min. Injection atropine
      0.01mg/kg、fentanyl 2 μg/kg 、 propofol 2mg/kg 、vecuronium bromide 0.1 mg/kg intravenously (IV)
      in turn.After loss of consciousness, children are promptly positioned supine with an adequate
      sized roll underneath the neck to establish optimal position.Achieving appropriate anesthesia
      depth,children are randomised to have inserted i-gel ,The jaw thrust maneuver are used to
      confirm anesthesia depth whether it is suitable for placing the laryngeal mask and
      facilitating its placement. We do not administer neuromuscular blocking during intraoperative
      period. Two anesthesiologists came to the hospital for working at least one year and
      experienced in inserting supraglottic airway devices in at least 200 pediatric patients. The
      device was inserted according to the manufacturer's recommendations .Device insertion was
      considered successful by observing bilateral chest wall movement,as well as a stable
      square-wave capnogram trace ,the lung breath sound with no audible leak .Three failed
      insertion attempts are considered failed insertion of the device, and patients were withdrawn
      from the study.Tracheal intubation was considered after failure of three times of laryngeal
      mask airway placement.

      Insertion time was measured from the moment a device was picked up until confirmation of the
      first wave on a capnogram，The ease of device placement was assessed using a subjective
      grading score of 1-4 (1: no resistance, 2: mild resistance, 3: moderate resistance, 4:
      inability to place the device) by the anesthesiologist. We also record the manipulations for
      improving device position, such as adjusting the insertion depth, conducting a jaw thrust
      maneuver, or flexion/extension of the head.

      Oropharyngeal leak pressure and fiberoptic view through the device were assessed.
      Oropharyngeal leak pressure was determined by closing the adjustable pressure-limiting valve
      to 30 centimeter water column(cmH 2 O) at the fresh gas flow rate of 3 L/min, switching the
      mechanical ventilation to manual ventilation, and reading the airway pressure on the monitor
      in the anesthesia machine which an audible leak on auscultation over neck was defined as OLP.
      The OLP was not allowed to exceed 30 cmH 2 O to avoid barotrauma, If mean airway pressure is
      higher than OLP or insufficient ventilation (lesser than 5 ml/kg) occurred during the airway
      maintenance, proper manipulations (pushing or pulling of device, extension or flexion of the
      head, jaw thrust) were performed. If appropriate manipulation does not solve the problem, the
      device should be removed and endotracheal intubation be performed. The anatomical position of
      the LMA in relation to the glottis was evaluated by placing a fiberoptic bronchoscope through
      the device .The fiberoptic view is classified into four grades by observing the fiberoptic
      views (grade 1: vocal cords not visible, grade 2: vocal cords and anterior epiglottis
      visible, grade 3: vocal cords and posterior epiglottis visible, grade 4: only vocal cords
      visible). The 8-12 French size gastric tubes are used for those groups. A well-lubricated
      gastric tube is prepared before inserted into the stomach through gastric port of airway
      device. The assessment of correct placement is through detection of injected air by
      epigastric auscultation or by aspiration of gastric content .A grading
      scale(1:easy,2:difficult,3：failure) is used for assessing the ease of gastric tube
      insertion.Easy is defined as placing the tube successfully in the first attempt,difficult is
      defined as placing the tube successfully within two attempts, failure is defined as inability
      to establish correct placement within three placements.Anesthesia was maintained using 2%~3%
      sevoflurane and remifentanil 0.2~0.4ug/kg•min.1 ug/kg fentanyl is added again before the skin
      incision and suture. At the end of surgery, the anesthetics are terminated. The patient was
      then moved to the postanesthesia care unit (PACU).We recorded heart rate, mean blood
      pressure, oxygen saturation, peak inspiratory pressure and complications during the induction
      and maintenance of anesthesia. At the conclusion of the surgery, when the tidal volume is >6
      ml/kg or end-tidal carbon dioxide(CO2) is less than 50 mmHg,we can stop the mechanical
      ventilation and keep the patient's spontaneous respiration. The LMA is removed when evidence
      of adequate emergence including spontaneous eye opening, grimacing using forehead and/or
      eyebrow, and purposeful movement. In addition,we also observed the complication such as
      coughing, bronchospasm, laryngospasm, desaturation (SpO 2 < 90%), regurgitation, aspiration,
      sore throat, blood-on LMA, postoperative nausea and vomiting (PONV), breath-holding and teeth
      or lip injury during anesthesia maintenance and emergence . A blinded investigator assessed
      all patients in the PACU and conducted a ward visit or telephone interview 24 h after the end
      of surgery. In our study, the primary outcome is oropharyngeal leak pressure，the secondary
      outcome are the rate of successful insertion at first attempt, fiberoptic view，insertion
      time，ease of insertion，ease of gastric tube insertion。 We recorded complications including
      coughing, breath-holding, desaturation, laryngospasm or bronchospasm，blood-on LMA, sore
      throat, postoperative nausea and vomiting (PONV), regurgitation, aspiration, teeth or lip
      injury.
    

Intervention name(s): laryngeal mask airway
Intervention type(s): Device
Intervention description(s): i-gel laryngeal mask airway is a supraglottic airway device made from a medical grade thermoplastic elastomer , is a non-inflatable device to create anatomical seal of the pharyngeal, laryngeal and perilaryngeal structures and avoid compression trauma.
Other intervention name(s): i-gel
Allocation: Non-Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: i-gel; pediatric; laryngeal mask airway; children