The ease of obtaining a good view of glottis with GlideScope® videolaryngoscope (Verathon Medical, Bothell, WA) has led to its increasing popularity over recent years. So much so that it is not only frequently used as the first-attempt intubation device in difficult intubation scenarios but is also being used increasingly as the first choice for securing airway in elective cases.1
I agree with Dr. Stanley1
that securing the airway in the shortest time and with minimal instrumentation is in the best interest of the patient and represents good clinical care. However, I tend to disagree that the GlideScope® meets all of these criteria. Although I find this device useful in difficult intubations, I rarely use it before performing a direct laryngoscopy in anticipated difficult intubations and almost never as a first-attempt intubation device in intubations not expected to be difficult. The major problem with GlideScope® is the difficulty in directing the endotracheal tube (ETT) toward the vocal cords.2
Hence, the use of stylet is almost mandatory while intubating under GlideScope® guidance. Despite the fact that a variety of stylets and ETTs have been suggested to increase the chances of successful intubation with GlideScope®, there are numerous reports of airway trauma during intubation attempts.3
The GlideScope® rigid stylet (Verathon Medical) is not always useful in directing the ETT toward the cords.4
However, a malleable stylet is usually effective.2
Although a 90° angulation of the stylet-loaded ETT is usually successful in most intubation attempts, sometimes a change in angulation is needed, and although it can be achieved easily, this requires the tube to be taken out before intubation can be attempted again, increasing the intubation time.
The eventual goal in airway management is to be able to pass the tube through the cords to ventilate the lungs and having a good view of the glottis greatly facilitates this goal; it is helpful to think of “laryngoscopy” and “intubation” as two separate steps in airway management, wherein difficulty could be encountered at the level of either step. Although satisfactory view of the glottis may sometimes not be achieved with direct laryngoscopy, intubation does not take very long if a reasonable view is achieved. GlideScope®, on the contrary, provides a good view of the glottis readily but the intubation is not always straightforward.2,3
Also, it is not uncommon for intubation to be successful with a direct laryngoscopy after the failure of GlideScope®-guided intubation.2
In patients with normal airway anatomy, GlideScope® use may be associated with an increased risk of airway trauma and postoperative sore throat.5
A recent study has demonstrated that in anticipated difficult intubations, although the incidence of difficult laryngoscopy (Cormack–Lehane ≥ III) is considerably less with GlideScope® compared with conventional Macintosh laryngoscope, the laryngoscopy time is similar between the two, and importantly, the intubation time is significantly less with the Macintosh blade.6
Experience from the emergency department also shows that although the rates of successful intubation on first attempt are not significantly different between GlideScope® and direct laryngoscopy, intubation using GlideScope® requires significantly more time.7
Moreover, an assistant is frequently required to pass the ETT over the stylet.2
Hence, I personally find it hard to justify using GlideScope® as the first-choice method for laryngoscopy, particularly for rapid sequence induction. Conversely, the equipment for conventional direct laryngoscopy is widely available, simpler to use, and less expensive than GlideScope®. In my opinion, the GlideScope® is a useful backup tool for intubations that failed with direct laryngoscopy. So, although I agree with Dr. Stanley's concern about a possible GlideScope® letter to the patients, I am more concerned about anesthesiology residents getting less experience with direct laryngoscopy, especially in difficult intubation scenarios because of an increasing GlideScope® use. Direct laryngoscopy is an essential skill, and every effort should be made to maintain and improve it, especially in difficult scenarios, or else, future generations of anesthesiologists may find difficult airways more challenging, should such gadgets not be available for some reason.
Deepak Sharma, M.D., D.M.
Harborview Medical Center, University of Washington, Seattle, Washington. firstname.lastname@example.org