Endotracheal Intubation Using a Bougie Through the Air-Q Intubating Laryngeal Airway
Condition: Airway Complication of Anaesthesia
Study type: Interventional

Summary: 
      The purpose of this study is to assess the success rate of bougie-guided endotracheal
      intubation compared to blind intubation through the Air-Q intubating laryngeal mask
    

Detailed description: 
      After ethical committee approval and written informed consent, 140 patients of either sex, >
      18 years old, ASA physical status I and II scheduled to receive general anesthesia with
      tracheal intubation for an elective surgical procedure will be enrolled in the study. They
      will be randomly allocated to one of two groups according to a computer generated list of 70
      patients each. Blind endotracheal intubation will be performed through the air-Q with bougie
      assisted (Group B) or without assistance (Group Q). Patients ASA physical status >III, mouth
      opening <2 cm, increased risk of aspiration, those with poor lung compliance, with lesions of
      the oropharynx or epiglottis and known or anticipated difficult tracheal intubation or
      facemask ventilation will be excluded from the study.

      In the operating room, the following monitors will be attached to the patients: five leads
      ECG, noninvasive blood pressure, pulse oximetry, ETCO2, anesthetic gas analyzer and
      neuromuscular monitoring (Infinity Kappa, Dräger, Lübeck, Germany). After adequate
      oxygenation, general anesthesia will be induced with 2 mg kg-1 propofol, 1-2 µg kg-1 fentanyl
      and 0.6 mg kg-1 rocuronium. Mask-ventilation with a mixture of oxygen and sevoflurane for an
      end-tidal concentration of 2% will be followed. The air-Q/ILA will be inserted once ulnar
      nerve train-of-four stimulation produced no visually detectable response while the patient's
      head in a neutral position. All airway manipulations (device insertion and tracheal
      intubation) will be performed by a senior anesthesiology staff member. The size of the air-Q
      will be selected on the basis of the patient's weight, in accordance with the corresponding
      manufacturer's recommendations. If ventilation with the device is unsatisfactory, the "Klein
      maneuver" corrects downfolding of the epiglottis by using a jaw thrust and an up-down
      maneuver of the ILA. During tracheal intubation through the air-Q/ILA, the tracheal tube is
      advanced to a depth of 12 to 15 cm so that the tip of the tube is close to the air-Q/ILA
      opening. Intubation through these supraglottic devices will be facilitated using a
      water-based lubricant. Then removal of the ILA immediately after tracheal intubation can be
      assisted by a stylet produced by the manufacturer. Tracheal intubation will be successful if
      ventilation through the tracheal tube produced an adequate chest expansion and a capnographic
      curve is obtained.

      In group B, the operator gently inserts the bougie through the air-Q/ILA while looking at any
      bulges in the neck to judge the approximate positioning of the bougie. As soon as the bougie
      enters the trachea, a characteristic click is felt by the assistant and the operator feels
      the bougie entering in a hallow space. Another sign for intra tracheal bougie insertion when
      the bougie reaches the small bronchus between 30 and 40 cm marks (distal hold up sign). The
      air-Q/ILA is then removed and a tracheal tube is railroaded over the bougie.

      Conventional single-use polyvinyl chloride (PVC) tracheal tubes (Mallinckrodt Company,
      Juarez, Chihuahua, Mexico) will be used for blind tracheal intubation in both groups: size
      7.0 mm ID tracheal tubes for patients weighing ≥50 kg and 6.0 mm ID tubes for patients <50
      kg. In both study groups, 3 attempts at device insertion and intubation will be allowed.
      Intubation will be only attempted if appropriate ventilation is obtained. Lung ventilation
      through the supraglottic device is permitted between intubation attempts. If tracheal
      intubation through the device is unsuccessful, it is performed by direct laryngoscopy.

      The following parameters will be measured:

        -  Mallampati score, mouth opening (cm), thyromental distance (cm), neck circumference (cm)

        -  Air-Q™ /ILA insertion: insertion time (seconds), ease of insertion (easy, difficult),
           number of attempts, 1st attempt success rate and grade of ventilation (adequate,
           possible or impossible).

        -  Tracheal intubation: number of attempts, intubation time (seconds), 1st attempt success
           rate and overall success rate, ,

        -  Air-Q insertion time: is the time from introducing the device in mouth till attachment
           to the circuit and capnographic trace is obtained.

        -  Bougie insertion time: is the time from removal of the breathing circuit from air-Q to
           the feeling of hold up sign.

        -  ETT insertion time: is the time from insertion of the tracheal tube in the device until
           confirmation by capnographic trace.

        -  Total intubation time in group Q (air-Q™ /ILA insertion time plus intubation time) and
           the total intubation time in group B (air-Q™ /ILA insertion time plus bougie insertion
           time plus bougie guided intubation time) were calculated.

        -  We also recorded the types of and number of adjusting maneuvers for each attempt,
           frequency of esophageal intubation, and any incidence of hypoxia (SpO2<95%).

        -  Incidence of airway complications at insertion of air-Q™ /ILA, gum elastic bougie and
           ETT as trauma to mouth, lips or tongue and visible or occult blood.

        -  Incidence of Airway Morbidity at 18-24 h postoperatively in both groups as sore throat,
           dysphagia, dysphonia and its degree (mild/moderate/severe)

        -  Hemodynamic data heart rate (HR) and mean arterial blood pressure (MAP) were also
           recorded at the following time intervals:

      T0, baseline before induction T1, before air-Q™ insertion T2, after air-Q™ insertion T3,
      before bougie insertion T4, after bougie insertion T5, before ETT insertion through the
      device T6, after ETT intubation T7, 1 min after intubation T8, 5 min after intubation T9, 10
      min after intubation

      Statistical Analysis

      As no previous study researching bougie guided endotracheal intubation through air-Q™, we
      consider this research as a pilot study and 70 patients in each group is suitable. Results
      are expressed as mean ± standard deviation (SD) or number (%). Categorical data was compared
      using Chi square test. Variables in both groups were compared using either unpaired t test or
      Mann Whitney test whenever it was appropriate. Intra-group comparison (within group
      comparison) between mean values of variables measured at baseline and different times was
      performed using repeated measures ANOVA followed by Bonferroni test if significant results
      was recorded. Data analysis was performed using Statistical Package for Social Sciences
      (SPSS) version 19 computer program. Significance was considered when P-value ≤ 0.05.
    

Intervention name(s): Air-Q
Intervention type(s): Device
Intervention description(s): Air-Q/Intubating Laryngeal Airway (air-Q/ILA, Cookgas LLC, St. Louis, MO, USA) is an extra glottis airway (EGA) used as a primary airway device or as an adjunct to tracheal intubation. The air-Q/ILA is available as a disposable (air-Q) or nondisposable (ILA) device
Other intervention name(s): Intubating laryngeal Airway
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Supportive Care
Keywords: Bougie; Air-Q; Insertion