The goal of this study is to assess the ease of ETT threading over the FOB on the right or left labial commissures in patients aging between 18 and 70 years old with ASA score I-II and undergoing any type of surgery. The main question it aims to answer is whether threading the tube on the right labial commissure during FOB intubation has a better success rate than threading the tube on the left labial commissure. Participants will be randomized via a computerized system into 2 groups (Group 1: Patients intubated with FOB by threading the tube on the left labial commissure and Group 2: Patients intubated with FOB by threading the tube on the right labial commissure). Researchers will compare the success rate of threading the tube on first trial, number of ETT threading trials, time to success, and incidence of intra-procedural complication between the two groups to see if threading the tube on the right labial commissure during FOB intubation has a better success rate than threading the tube on the left labial commissure.

Fiberoptic bronchoscope (FOB) intubation is the gold standard technique for intubating patients with predicted difficult airway. Different maneuvers have been used to facilitate threading the endotracheal tube (ETT) over the fiberoptic bronchoscope including jaw thrust, stretching the tongue, rotating the ETT 90 degrees anticlockwise or using smaller tubes. To our knowledge threading the ETT with the FOB on the left or right lip commissures has not been investigated previously. Improving the ease of ETT threading on the right or left labial commissures could change our FOB intubation management.

The aim is to assess the ease of ETT threading over the FOB on the right or left labial commissures.

Patients between 18 and 70 years old with ASA score I-II and undergoing any type of surgery in the operating rooms at the American University of Beirut Medical Center will be randomized via a computerized system into 2 groups:

Group 1: Patients intubated with FOB by threading the tube on the left labial commissure Group 2: Patients intubated with FOB by threading the tube on the right labial commissure The primary outcome is the success rate of threading the tube on first trial. Secondary outcomes include number of ETT threading trials, time to success, and incidence of intra-procedural complications.

Inclusion Criteria:

• Patient aged 18 to 70 years
• Any surgery requiring general anesthesia
• ASA 1 and 2

Exclusion Criteria:

• Patients aged less than 18 or more than 70 years old.
• ASA 3 and 4 patients.
• Patients who need a rapid sequence induction (including pregnant women) or those who have an increased risk of aspiration.
• Patients who need awake fiberoptic intubation for a difficult airway or any other reason