We read with interest the letters to the Editor regarding our case reports, published recently in Anesthesiology, describing the use of the Airtraq® laryngoscope (AL) in morbidly obese parturients undergoing emergency cesarean delivery.1We think that it is a privilege to have our reports reviewed by such experts in the field of airway management.
In regard to Dr. Neustein's comments, positioning the AL in a difficult airway management algorithm is the result of a long educational and clinical process conducted through an airway management teaching program begun almost 5 yr ago with the validation of a predefined algorithm for the unexpected difficult airway in the operating room2and then in prehospital conditions.3We have been conducting for 3 yr in France the first national University Diploma of Airway Management program, and now this French teaching program has evolved into a European diploma, the EXCLAM (Excellence Level in Airway Management). In 2005, with the arrival on the French market of the LMA CTrach ™ (CT; SEBAC, Pantin, France), we have implemented our algorithm built in case of the unexpected difficult airway, and finally 1 yr ago we incorporated one of the new generation of tracheal intubation devices that we call the “glottiscopes,” such as the AL (VYGON, Ecouen, France). Since we submitted our case report to Anesthesiology, a third “glottiscope,” the AirwayScope (PENTAX, Argenteuil, France), has become available, and we had the opportunity of testing it. These “glottiscopes” are equipped with both video-endoscopic resources and a built-in channel (or tube) driving the endotracheal tube in regard to glottis aperture into the trachea. The AL and, more generally, the other “glottiscopes” are really different from the basic, although sexy-looking, video-laryngoscopes, such as the GlideScope® (VERATHON Medical, Strasbourg, France) or the McGrath® (LMA North America, San Diego, CA), that are efficient at improving the Cormack and Lehane score but do not systematically facilitate and shorten tracheal intubation in case of a difficult airway.
Of course, we are concerned with cost-effectiveness, and we agree that $80 is certainly too expensive for a single-use primary airway management device. However, we are sure that if the AL were sold for less than 10% of its actual price, we would not use the Macintosh laryngoscope anymore in potentially difficult airway patients such as morbidly obese patients. Almost all of the anesthesiologists in our department have completed their learning curve with the AL. All are experts in airway management, and our university hospital is now considered as an Excellence Center for teaching airway management. In addition to cadaver training and manikin workshops, physicians become involved in regularly updated programs on new techniques in airway management. Teaching clinical use of new airway devices to residents or visiting physicians is systematically supervised and filmed. Our teaching program has been funded mainly by the university and private sources coming from attendees participating in our diploma program. Because his English is of better quality than ours, we thank Dr. Neustein for his nice description of the AL and its use. Moreover, we accept his advice on how to apply the Sellick maneuver.
In response to Drs. Chandan and Sadashivaiah, early and recent reviews have identified airway management complications such as aspiration of gastric contents, failed tracheal intubation, esophageal intubation, and airway obstruction as associated with anesthesia-related maternal mortality in Western countries. Moreover, some reports have recognized morbid obesity as a worsening factor of airway management difficulty. We believe that airway protection against aspiration of gastric contents requires insertion of a cuffed tube into the trachea as quickly as possible. Any device improving the laryngoscopic view (specifically in morbidly obese patients) and allowing visual control of the endotracheal tube passing through the vocal cords may eliminate the risk of esophageal intubation and fatal airway obstruction. Therefore, the AL, which combines the abilities to (1) facilitate the glottis view, (2) control the transglottic passage of the tube, and (3) dramatically reduce the time (elapsing between loss of consciousness to inflation of the cuff) to securing the airway, is of major interest for emergency and particularly obstetric anesthesia. For these reasons, we placed the AL as a brief plan B after failed direct laryngoscopy in emergency cesarean delivery patients and proposed it as a primary airway management device when parturients showed predictable criteria for difficult intubation. Moreover, we observed that video-controlled emergency tracheal intubation with the AL helped the operator performing the Sellick maneuver to adapt external manipulations over the cricoid area to facilitate glottis access without releasing cricoid pressure intensity. This interesting adaptation of the Sellick maneuver is not possible with the Macintosh laryngoscope when the glottis view is poor. As already stated, almost all of the anesthesiologists in our department have completed their learning curve with the AL. We have placed more than 250 ALs. We are conducting a randomized study in the intensive care unit, and we have recently been involved in clinical trials evaluating the AL in anticipated difficult airway patients, including elective cesarean deliveries. Accepted manuscripts are ready to be edited. We are sure (if this response to the Editor fails) that our data (and those of others coming from different teams) will convince Drs. Chandan and Sadashivaiah that our positioning of the AL in a difficult airway algorithm is not “premature and daring” but rather results from a long maturation (almost 2 yr of training and practice) and rational reflection on the optimal airway management strategy to apply in emergency obstetric situations. We believe that the AL is not a “magic bullet” but just an efficient airway device to facilitate tracheal intubation of difficult airway parturients. We did not aim to conquer any market but rather propose a reasonable and efficient alternative to the Macintosh laryngoscope, which was proposed almost 50 yr ago. We are sure that Drs. Chandan and Sadashivaiah will find on PubMed (May through August 2007) some interesting articles describing the use of the AL in difficult airway patients.
We are aware of the magnificent works performed by Dr. Goldman et al. ,4–6and we share similar opinions with Liu et al. 7We have been involved in the first clinical trials with the CT,8,9and we are still working on the evolution of this wonderful device. More than 300 CTs have been placed at our University Hospital of Paris, and not only for clinical trials. We confirm that the CT is the most effective ventilatory device, and we have also demonstrated great tracheal intubation performance of the CT in normal8and difficult airway patients.9Unfortunately, we are not certain that emergency tracheal intubation with the CT may prevent the risk of aspiration in case of true gastric content, as in our emergency cesarean delivery patients. Indeed, time to securing the airway with the CT requires, in expert hands, 1.5–2 min without real protection of the airway. First, the Sellick maneuver must be resumed during CT insertion. Second, maneuvers performed just after CT insertion to adjust ventilation (requested in 30–40% of cases) augment the risk of gastric inflation and increase pressure and regurgitation. Finally, the most risky period during CT manipulations occurs when maneuvers performed to optimize the view (requested in 30–50% of cases) require large-amplitude up-and-down movements of the mask. During these maneuvers, the distal tip of the mask is necessarily removed from its “protective” place in the hypopharynx and exposes the airway to possible regurgitated contents from the stomach. For all of these reasons, we placed the CT in plan C for emergency situations in case of failure of the AL to intubate within 1 min and in plan B in case of poor oxygenation during airway management for any elective or emergency cases. Finally, we believe that the AL is the airway of choice in the situation of difficult direct laryngoscopy when there is urgency to secure the airway with a cuffed endotracheal tube, as in emergency obstetric situations.
*Jean Verdier University Hospital of Paris, Bondy, France, and Paris 13 School of Medicine, Bobigny, France. firstname.lastname@example.org