The general aim of the study is to observe whether the use of the Mc Grath™ videolaryngoscope instead of direct laryngoscopy can represent, as in the case of the single-lumen tube, an added value in the placement of the double-lumen tube for surgical procedures involving one-lung ventilation, making intubation on the first attempt more likely and quicker. Secondary objectives include evaluating the presence of an advantage of the Mc Grath™ videolaryngoscope over direct laryngoscopy for the correct placement of the double-lumen tube, the need for additional maneuvers during the intubation procedure, and the presence of intra- and post-procedural complications.

Placement of the double-lumen tube (DLT) can be more challenging because the endobronchial tube is larger (thus worsening glottic view) and more rigid (increasing the risk of trauma and reducing maneuverability during placement). An anatomically easy airway can become more demanding when there's a need to place a double-lumen tube. Success rates and intubation times can vary significantly. The superiority of videolaryngoscopy (VLS) over direct laryngoscopy (DL) is clear regarding the placement of the single-lumen endotracheal tube (SLT). Its use is now "recommended" as the first attempt in anticipated difficult airways and "suggested" for all routine intubations. To date, 19 prospective randomized controlled trials have compared the effectiveness of six VLS devices for DLT intubation versus DL in patients with anticipated non-difficult airways. Key endpoints included glottic view, intubation time, success rate, intubation difficulty rating, incidence of malpositioning, postoperative sore throat, hoarseness, procedure-related complications, and intubation-related stress response. Apart from a superior glottic view with VLS compared to DL, consistent results have not emerged across different studies. This heterogeneity may be attributed to differences in the experience of the operators involved, the type of VLS used, and finally the definition of the primary endpoint. Conducting a randomized controlled study with adequate and larger sample size than previous ones and a homogeneous population can ascertain whether VLS can represent, as in the case of SLT, an added value in DLT placement, guiding clinicians towards its routine use.

It is worth noting that current guidelines on DLT intubation do NOT recommend the "1st choice" use of VLS, a recommendation already existing for SLT placement. For this reason, in clinical practice, both devices are effectively used interchangeably, largely based on individual clinician preferences, which moreover possess comparable expertise in both direct laryngoscopy and videolaryngoscopy.

Aim: To compare the effectiveness of a single videolaryngoscope, the Mc Grath™, versus direct laryngoscopy in placing the double-lumen tube in surgery.

Experimental design: Multicentric Randomized Controlled Trial Primary endpoint: evaluation of the advantage of the Mc Grath™ videolaryngoscope over direct laryngoscopy for double-lumen tube intubation.

Secondary endpoints: Evaluation of the advantage of the Mc Grath™ videolaryngoscope over direct laryngoscopy for intra- and post-procedural complications, need for additional maneuvers, and correct placement of the double-lumen tube.

Study duration: 24 months

Inclusion Criteria:

• Age > 18 years
• General anesthesia
• One-lung ventilation via double-lumen tube

Exclusion Criteria:

• Patients who refuse to consent to participation in the study.
• Patients scheduled for awake intubation due to pre-operative evaluation findings of predictors of difficult oxygenation that contraindicate intubation under general anesthesia.
• Patients with anatomical anomalies leading to tracheal and/or laryngeal displacement/compression.
• Patients with contraindications to double-lumen tube placement.