Tracheal intubation (TI) is one of the fundamental and most recognized techniques in
Anesthesiology, also essential in all units treating urgent pathology and critical
patients. It involves advancing a tube through the vocal cords into the trachea to
ventilate the patient. In thoracic surgery, it is often necessary to achieve lung
isolation, ventilating only one lung while the operated lung remains collapsed and
immobile. To achieve this, it is common to intubate the patient with a special tube: a
double-lumen tube (DLT), larger than usual because it provides two ventilation channels,
one for each lung.
Tracheal intubation with a DLT presents some peculiarities: its larger size and stiffness
make manipulation and orientation in the oropharynx difficult. It has a curve at its
distal end (the bronchial lumen) designed to slide into the left or right main bronchus
as needed. The fact that the DLT passes between the vocal cords does not ensure its
proper placement and function. Therefore, DLT intubation requires practice and
experience, both to slide it between the vocal cords and to position it properly.
The classic technique for DLT intubation is "Direct Laryngoscopy" (DL). A traditional
laryngoscope with a Macintosh blade is used to move the upper airway structures aside to
allow direct visualization of the glottis. In recent years, to facilitate tracheal
intubation, different videolaryngoscopes have appeared. A videolaryngoscope is a device
similar to a traditional laryngoscope that allows, thanks to an image sensor located at
its end, indirect visualization of the glottis on an integrated or external screen.
There is strong evidence for the benefit of using a VL over traditional DL in single-tube
intubation in adult patients. However, although the use of VL for DLT intubation is
becoming more common, there are few studies with small sample sizes comparing VL to DL
for DLT intubation, so the evidence of its advantages or disadvantages is of low quality.
It could improve glottic exposure and the percentage of success on the first attempt,
although there is a possibility of increased tube malposition incidence and delayed
intubation.
Therefore, Investigators propose a prospective, multicenter, randomized study comparing
the traditional Macintosh blade laryngoscope (direct laryngoscopy) with the
videolaryngoscope to facilitate orotracheal intubation with double-lumen tube in patients
scheduled for thoracic surgery requiring lung isolation.