AMBU AScope2 Fiberoptic Intubation Versus Fastrach Intubating LMA
Condition: Supraglottic Airway
Study type: Interventional

Summary: 
      The purpose of this study is to compare two types of supraglottic airways (SGA), the Ambu®
      Aura-I and the Intubating Laryngeal Mask Airway (ILMA), regarding time to intubate, ease of
      insertion, sealing properties, optical view upon fiberoptic examination regarding the Ambu
      Aura-I, ease and success rate of intubation, airway morbidity, and patient comfort in
      patients undergoing general anesthesia for elective surgery.
    

Detailed description: 
      The study will include a total of 66 patients. Patients will be randomized into 2 groups
      through a computer generated randomization schedule. Patients in group A (N= 30) will be
      intubated using Ambu Aura-I and the Ambu aScope and patients in group B (N= 30) will be
      intubated using Intubating LMA. Patients will only be tested with one device.In the operating
      room, standard monitoring devices will be applied including a pulse oximeter, 3 lead (at
      least) ECG and blood pressure cuff; the latter could be invasive or non-invasive depending on
      the nature of the surgery. Baseline measures of BP, pulse, oxygen saturation, and CO2 will be
      made. The time will be noted before any sedation or anesthesia is administered. Vital signs
      will be recorded after induction of anesthesia, after insertion of SGA, and again after
      successful intubation.

      General anesthesia will be induced by bolus administration of propofol (1.5 to 2mg/kg) and
      fentanyl (1mcg/kg), and maintained with an inhalational agent. Rocuronium (0.6 mg/kg) will be
      administered to provide muscle relaxation and a mixture of sevoflurane or isoflurane and
      nitrous oxide will be utilized for maintenance of anesthesia once the ability to mask
      ventilate is confirmed. The lungs will be mechanically ventilated with a semi-closed circle
      system to maintain an end-tidal CO2 near 35 mmHg. Patients' lungs will be ventilated via
      anesthesia mask 100% oxygen until the patient is completely relaxed.

      The size of the SGA device used will be based on manufacturer's recommendations and clinical
      evaluation of the anesthesiologist. The SGA device will be placed using standard technique
      and jaw lift will always be performed to aid in placement. The user will record ease of
      insertion on a scale (1-5) and number of insertions required will also be recorded. A new
      attempt is considered to begin if the tip of the cuff is withdrawn to the level of the lips.
      Accurate ventilation is achieved when the CO2 signal is rectangular and the mask is airtight
      at a respiratory pressure of up to 20 cm H2O. Time will be recorded from when the tip of the
      device cuff is at the mouth opening and stopped when first CO2 waveform is recorded.

      Once ventilation is achieved, the patients in group A will be intubated through the shaft of
      Aura-I via the the Ambu aScope. If the epiglottis is down folded and obscuring optical view,
      jaw lift can be performed by an assistant to improve visualization of the cords. The aScope
      will be advanced until the carina is visualized and then the ETT is railroaded via the aScope
      into position (5cm above carina or cuff of ETT just below vocal cords). Once the ETT is
      successfully inserted, the cuff of the Aura-I will be deflated and the patient is ventilated
      via the ETT. If it is not possible to intubate, the ETT should be rotated 90°
      counterclockwise and jaw lift should be performed to help with intubation. If unsuccessful
      after two attempts, the anesthesiologist will proceed to intubate in standard fashion. The
      patients in group B will be intubated by ETT via the Intubating LMA as is standard procedure.

      Once the procedure has finished and the patient is adequately reversed as determined by nerve
      stimulation, the cuff will be reinflated and the ETT will be removed. Ventilation will resume
      via the SGA. Once the ETT is withdrawn, the cuff will be adjusted to 60cm H2O using a cuff
      pressure manometer. The oropharyngeal leak pressure(OLP) is determined with a 60 cm H2O
      intracuff pressure by closing the expiratory spill valve and then closing the expiratory
      valve of the circle system at a fixed gas flow of 3 L/min, without any respiration. The
      airway pressure at which equilibrium is reached and air leaks from the mouth or into the
      stomach, as sign of leak of the laryngeal mask is noted. Esophageal leak is determined by
      stethoscopy of the epigastrium and oropharyngeal leak is dectected listening for air leak
      over the mouth.

      The peak airway pressure is not allowed to exceed 40 cmH2O. After OLP measurement and once
      the patient is adequately breathing on their own, the SGA can be removed.
    

Intervention name(s): AMBU Aura-I/aScope 2; LMA Fastrach Single Use
Intervention type(s): Device; Device
Intervention description(s): Once ventilation is achieved, the patients in group A will be intubated through the shaft of Aura-I via the the Ambu aScope.; The patients in group B will be intubated by ETT via the Intubating LMA as is standard procedure.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: Laryngeal Mask Airway; LMA; Intubation; AMBU; AScope; Aura-I; Fastrach; Fiberoptic; Disposable Fiberoptic; Blind Intubation; Fiberoptic Intubation