A comparison of two techniques for inserting the Airtraq^™ laryngoscope in morbidly obese patients

Abstract

SummaryWe postulated that video-controlled tracheal intubation with the Airtraq TM laryngoscope using the reverse manoeuvre instead of the standard technique of insertion could facilitate the airway management of morbidly obese patients. For the reverse manoeuvre the laryngoscope is inserted 180°opposite to that recommended, and once in place rotated into the conventional pharyngeal position. Eighty (40 lean and 40 morbidly obese) ASA I-III adult patients were randomly allocated to four equal groups to compare the standard technique to the reverse manoeuvre for inserting the Airtraq laryngoscope. Video-controlled and clinical tracheal intubation characteristics were recorded. The reverse manoeuvre did not influence tracheal intubation characteristics in the group of lean patients. In the group of morbidly obese patients, the standard technique of insertion was not satisfactory in 20% of cases and the reverse manoeuvre facilitated, speeded and secured tracheal intubation. The Airtraq TM (Prodol Meditec S.A., Vizcaya, Spain) disposable laryngoscope was designed to provide a view of the glottis without altering the normal alignment of the oral and pharyngeal axes. The Airtraq laryngoscope has been used in normal airways [1] and under simulated difficult airway scenarios [2]. Four experienced anaesthetists in our department received training in the use of the Airtraq laryngoscope using a manikin and unfixed cadavers. Following 2 months of experience using the Airtraq laryngoscope in patients undergoing bariatric surgery, the major factor determining the time for tracheal intubation appeared to be difficulty in placing the laryngoscope in the pharynx of some obese patients. We postulated that tracheal intubation might be facilitated if the Airtraq laryngoscope was inserted 180°opposite to that recommended and, once in place, rotated into the conventional pharyngeal position (reverse manoeuvre). After testing the reverse manoeuvre in cadavers, we decided to compare its effectiveness with the standard technique of insertion in lean and morbidly obese patients undergoing elective surgery. ) and 40 morbidly obese (BMI > 35 kg.m )2 ) patients were enrolled in this prospective study. Randomisation of the technique for inserting the Airtraq laryngoscope was performed at the pre-operative anaesthetic visit. Patients were assigned to the standard technique or the reverse manoeuvre using sealed envelopes opened by the anaesthetist in the operating room. The four trained anaesthetists involved in the study were experienced in tracheal intubation using the Airtraq laryngoscope. They all performed the same number of tracheal intubations in lean and morbidly obese patients. Patients with limited mouth opening (< 3 cm), suffering from symptomatic gastric reflex or hiatus hernia, and those in whom suxamethonium was contra-indicated, were not included.

Tracheal intubation in patients with rigid collar immobilisation of the cervical spine: a comparison of Airtraq® and LMA CTrach™ devices*

“…This is in keeping with the findings of several authors who have commented on the haemodynamic changes following insertion of different intubating aids [14,29,30].…”

“…For each of the devices studied, the appropriate size and insertion technique was used according to the manufacters' guidelines [14,15]. The technique was considered to have failed if tracheal intubation was not achieved within 120 s or within a maximum of three intubation attempts.…”

Evaluation of the Airtraq® and Macintosh laryngoscopes in patients at increased risk for difficult tracheal intubation*

“…In manikin studies, the Airtraq performs better than the Macintosh laryngoscope in the simulated difficult airway when used by experienced [3], inexperienced [4] and even novice [5] laryngoscopists. Recent reports have highlighted the utility of the Airtraq in a number of difficult airway settings, including post traumatic asphyxia [6], in morbid obesity [7], and following failed conventional approaches to tracheal intubation [8].The purpose of this study was to evaluate the usefulness of this new device for use by experienced anaesthetists in a randomised controlled trial of patients at increased risk for difficult intubation. We hypothesised that, in comparison with the Macintosh laryngoscope, the use of the Airtraq would be result in reduced laryngoscopy times, lower intubation difficulty scale (IDS) scores, and reduced haemodynamic stimulation following intubation.…”

“…In manikin studies, the Airtraq performs better than the Macintosh laryngoscope in the simulated difficult airway when used by experienced [3], inexperienced [4] and even novice [5] laryngoscopists. Recent reports have highlighted the utility of the Airtraq in a number of difficult airway settings, including post traumatic asphyxia [6], in morbid obesity [7], and following failed conventional approaches to tracheal intubation [8].…”

A comparative evaluation of conventional Macintosh laryngoscope and the Airtraq® in different intubation scenarios

“…2 Not only the ease of visualising the glottic opening is there with the Airtraq® but also it has the added advantage of having less haemodynamic stimulation of these patients. 3 Recent reports have highlighted the utility of Airtraq® in many other difficult situations including morbidly obese patients 4 and failed conventional approaches to tracheal intubation.…”