Published online Dec 2, 2021. doi: 10.5313/wja.v10.i2.7
Peer-review started: March 8, 2021
First decision: May 14, 2021
Revised: May 31, 2021
Accepted: October 15, 2021
Article in press: October 15, 2021
Published online: December 2, 2021
In anesthesia practice, orotracheal intubation remains the primary concern of the anesthesiologist. The introduction of video laryngoscopy (VL) has increased the success rate of orotracheal intubation; however, conflicting results have been reported regarding the usefulness of the current technique with VL in clinical practice.
To describe a modification to improve intubation with VL, followed by evaluation of the practice in vivo.
First, a mannequin trial was conducted with operators having different experience and background. Then, a retrospective analysis was performed for an > 1-year period with patients who underwent general anesthesia with orotracheal intubation. The endotracheal tube used had been pre-formed with two curves. Stepwise intubation had been performed with direct eye vision, followed by screen assistance and rotation of the tube as needed to direct it toward the glottis. In the mannequin trial, the outcome measures were quantification of torque (force with angular acceleration during levering), need for external maneuvers, and time to intubate. In the clinical experience, orotracheal intubation used VL (pre-formed tube) or direct laryngoscopy (DL) at the anesthetist’s discretion and throat discomfort was reported by the patient.
In the mannequin trials using VL, there was less torque with the pre-formed tube than with a regular tube (8% and 65%, respectively). The first-pass rate was higher with the pre-formed tube (95%) than with a regular tube (81%). However, the time to intubate was longer with the pre-formed tube than with a regular tube (22 s and 12 s, respectively). In clinical practice, 562 patients underwent surgery under general anesthesia with orotracheal intubation using either VL (n = 244) or DL (n = 318) at the discretion of the attending anesthetist. VL was specifically planned in 62 of the patients, due to anticipated difficulty. Second attempts by readjustment of the curve of the tube were significantly fewer with VL than with DL (10% vs 18%). Throat discomfort was reported by fewer patients who underwent VL than those who underwent DL (6% vs 24%).
Pre-formed endotracheal tube with stepwise insertion produces less torque, fewer external maneuvers and higher first-pass success rate during VL intubation. Further, prospective studies are warranted.
Core Tip: Video laryngoscopy (VL) is gaining popularity in the practice of endotracheal intubation. Failure of VL-assisted intubation may be attributed to the fact that practitioners use the same technique employed for traditional rigid laryngoscopy. We describe a technique based on pre-forming the endotracheal tube with two specific curves and using a stepwise insertion technique to facilitate the VL and achieve a higher success rate. The tool was tested in a mannequin trial first and then applied to clinical practice. The first-pass success rate was higher, with minimal torque and fewer external maneuvers required.