Three Different Techniques for Tracheal Intubation Via Supraglottic Airway Devices

Prospective, randomized, comparative, clinical, controlled study, that is approved by the Ethics Commitee of the University of Patras (10.12.2019) and takes part in the University Hospital of Patras. Depending on the supraglottic airway device (SGA)/ laryngeal mask airway (LMA) used to achieve intubation (Fastrach, I-gel, Protector), partcipants will be randomly allocated into three groups; Group A, B and C (Fastrach, I-gel, Protector respectively).

In the preoperative setting, a complete preanesthetic evaluation will be performed, including a detailed airway assessment (prediction of difficulty in face mask ventilation, insertion of SGA/LMA and intubation).

All patients are scheduled to undergo an elective surgery under general anesthesia. Before induction, all patients will be preoxygenated with FiO2 100% for at least 5 minutes. After induction, using rocuronium 0.6mg/kg to facilitate neuromuscular blockade, face mask ventilation follows.

• Group A- Fastrach: The intubating laryngeal mask airway (Fastrach) will be placed to the patients of this group. After the mask is correctly placed and patients are adequately ventilated, they will be intubated through the mask using its own endotracheal tube according to the blind technique insertion.
• Group B- I-gel: The supraglottic airway device (I-gel) will be placed to the patients of this group. After the mask is correctly placed and patients are adequately ventilated, they will be intubated through the mask using a fiberoptic bronchoscope to guide endotracheal tube's placement.
• Group C- Protector: The supraglottic airway device (Protector) will be placed to the patients of this group. After the mask is correctly placed and patients are adequately ventilated, they will be intubated through the mask using a fiberoptic bronchoscope to guide endotracheal tube's placement.

In all groups (A, B, C) up to 3 attempts of SGA/LMA placement and up to 3 attempts of intubation are allowed to be made.

In case of an emerging unpredicted difficult airway and a concurrent unsuccessful SGA/LMA placement, then the algorithm of the difficult airway will be immediately followed. Video-assisted laryngoscopy will be the first option rescue alternative.

The time of the whole procedure from the beginning of SGA's/LMA's placement effort until the successful intubation will be recorded, along with the evaluation of the success rate of first intubation attempt.

Inclusion criteria

• Patients (age ≥ 18 yrs) scheduled for an elective surgery under general anesthesia
• Written informed consent to participate in the trial

Exclusion criteria

• Age < 18 yrs
• Non- elective (urgent/ emergency) procedures or multi-trauma patients
• Obstetric population
• Surgery performed under regional anesthesia
• Contraindication to LMA insertion
• Predicted difficulty in LMA insertion (at least one out of four "RODS" criteria)
• Contraindication to the use of neuromuscular blockade or situations that require spontaneous breathing
• Indication for awake intubation or surgical airway
• Patients' involvement in another clinical trial