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The Optical Laryngoscope: Experiences with a New Disposable Device for Orotracheal Intubation

Schirin M. Missaghi, MD,1 Klaus Krasser, MD,1 Hildegard Lackner-Ausserhofer, MD,1 Anita Moser, MD1, and Ernst Zadrobilek2

1Staff Anesthetist and Intensive Care Physician, Department of Anesthesia and Intensive Care, Empress Elisabeth Hospital of the City of Vienna, Vienna, Austria. 2Associate Professor of Anesthesia and Intensive Care and Director, Department of Anesthesia and Intensive Care, Empress Elisabeth Hospital of the City of Vienna, Vienna, Austria.

Address correspondence and comments to Ernst Zadrobilek.

Received from the Department of Anesthesia and Intensive Care, Empress Elisabeth Hospital of the City of Vienna, Vienna, Austria.

Statements The authors have no financial relationship with the manufacturer or any of the distributors of the airway management device used in this clinical report. This clinical investigation was presented in part at the Difficult Airway Society Annual Meeting, Portsmouth, United Kingdom, November 21-23, 2007.

Acknowledgements The authors thank the staff anesthetists and the anesthesia residents who voluntary participated in this study and the manufacturer and the Austrian distributor of the Airtraq Optical Laryngoscope for making this airway management device available free of charge for study purposes.

Key Words : Airtraq Optical Laryngoscope.

Published: December 31, 2007.

The correct citation of this clinical investigation is: Missaghi MS, Krasser K, Lackner-Ausserhofer H, Moser A, Zadrobilek E. The Airtraq Optical Laryngoscope: experiences with a new disposable device for orotracheal intubation. Internet Journal of Airway Management 4, 2006-2007. Available from URL: http://www.adair.at/ijam/volume04/clinicalinvestigation02/default.htm Date accessed: month day, year.

Last updated: December 31, 2007.

Abstract

Objectives: The battery-powered Airtraq Optical Laryngoscope (AOL) is a new disposable device developed to facilitate orotracheal intubation in with normal and difficult airways, but there are only limited data on its use in clinical practice. We therefore evaluated the AOL in anesthetized patients requiring orotracheal intubation and determined whether successful tracheal intubation correlates with conventional laryngoscopic view grading (CLV).

Design: Patients with previously experienced difficult conventional tracheal intubation, anatomic features predictive for difficult conventional laryngoscopy and tracheal intubation, and/or obesity were given preferential enrollment into the study. Therefore, this clinical investigation represents data of a prospective, but non-consecutive observational study.

Setting: The study was performed at a community hospital with a reference center for the management of thyroid .

Patients: Two hundred and fourteen patients undergoing elective thyroid surgery were investigated.

Operators: The operators (10 staff anesthetists and 2 anesthesia residents) were novice users of the AOL. They first received formal hands-on training on a suitable airway management model, were instructed during the early series of performance on patients by an experienced AOL user, and performed AOL-assisted laryngoscopy and tracheal intubation attempts on from 14 to a maximum of 20 (median: 18) patients.

Interventions: CLV was performed with a standard Macintosh laryngoscope (optimum depth of blade insertion determined by the vallecula and using gentle lifting force without external laryngeal manipulation): grade 1, visualization of the entire laryngeal aperture; grade 2, visualization of just the posterior portion of the laryngeal aperture; grade 3, visualization of only the arytenoids; grade 4, visualization of only the epiglottis; and grade 5, visualization of just the soft palate. The laryngeal views obtained with the AOL were evaluated using the same technique for laryngoscopy and the 5-grade scoring system. The tracheal tube (TT) was placed in the tube-guide channel on the right side of the AOL blade and advanced through the laryngeal aperture into a midtracheal position when laryngeal structures were in the center of the view.

Measurements and Main Results: Grades 1 to 5 at CLV were obtained in 74, 62, 44, 32, and 2 patients, respectively. The success rate of AOL-assisted tracheal intubation at the first attempt was 97 percent (207/214 patients) with laryngeal views of grade 1 in all of these patients. Minor problems and difficulties with impeded blade insertion (due to limited mouth opening and/or restricted pharyngeal space) and impeded TT advancement (during laryngeal and/or tracheal passage) were encountered in 9 and 12 percent, respectively; there were no problems with poor visibility (due to the presence of secretions and/or fogging of the optical system). Seven patients required a second attempt for tracheal intubation; the causes were failed identification of anatomical structures (one ), failed TT advancement during laryngeal passage (four patients), and requirement of downsizing the TT for unimpeded and atraumatic laryngeal passage (two patients). In all patients, AOL-assisted tracheal intubation was successful (after a maximum of two attempts).

Conclusions: Provided formal instruction, success of tracheal intubation with the AOL performed by novice users (staff anesthetists and anesthesia residents) was not affected by CLV. The AOL proved to be uniquely useful for routine and difficult laryngoscopy and tracheal intubation.

Introduction

The battery-powered, portable Airtraq Optical Laryngoscope (AOL; manufactured by Prodol Meditec, Vizcaya, Spain) is a new disposable device (with an anatomically shaped blade) developed to facilitate orotracheal tracheal intubation in patients with normal and difficult airways. The AOL allows for the transmission of a color image to the view finder at the proximal end of the laryngoscope handle (by internal arrangements of optical components), usually providing the operator a panoramic view of the laryngeal aperture when properly inserted. However, the tube-guide channel at the right side of the AOL blade [to guide the tracheal tube (TT) into the correct position] may incorporate some problems with deflection and impingement of the TT on surounding laryngeal structures.

The performance of the AOL compared with the Macintosh laryngoscope for orotracheal intubation was initially evaluated by Maharaj and co-workers on an airway management (AM) model, simulating easy and difficult laryngoscopy situations: the operators were anesthetists without prior experience of using the AOL (7), and medical students (4, 5) and medical residents (6) inexperienced in AM techniques. In general, the AOL provided superior tracheal intubation conditions, resulting in greater success of tracheal intubation, particularly in simulated difficult laryngoscopy situations.

The first randomized evaluation of the AOL in anesthetized patients (with normal airways and low risk of difficult laryngoscopy) requiring orotracheal intubation was performed by the same working group (9), published in November 2006; in comparison to the Macintosh laryngoscope (including 30 patients in both groups), the AOL resulted in modest improvements in the ease of use and the intubation conditions, subjectively rated by the operators (anesthetists experienced with both laryngoscopes). Recently, Dhonneur and co-workers (2) communicated their favorable experiences with the AOL for AM in two morbidly obese obstetric patients.

The introduction of a new device for AM into routine clinical practice requires validation of performance in controlled studies. The AOL is recommended by the manufacturer for routine and difficult laryngoscopy and tracheal intubation, but there are only limited published data on its use in patients (2, 9). We conducted this study exclusively on patients presenting for thyroid surgery to recruit a sufficient number of patients with variable degrees of airway difficulties and conventional laryngoscopic views.

The handling of the AOL is similar to conventional laryngoscopy with the Macintosh laryngoscope that we anticipated easy adoption by novice users. Because of expected problems of viewing the intubation process through the view finder and difficulties in manipulating the TT through the laryngeal aperture into a midtracheal position, the operators first received formal hands-on training on a suitable AM model and were then instructed during the early series of performance on patients by an experienced user of the AOL.

Materials and Methods

Legal and Ethical Considerations. The study was approved by the Institutional Review Board. Informed patient consent was obtained for the planned strategy of airway management (AM) and the anonymous use of patient data for scientific purposes.

Patient Selection. The study was performed at a community hospital with a reference center for the management of thyroid diseases; the institutional department of general surgery performs more than 1200 thyroid surgical procedures a year. Over a study period of 9 months, adult patients with American Society of Anesthesiologists physical status classification 1, 2, or 3 requiring orotracheal intubation for elective thyroid surgery were investigated. Patients with gastroesophageal reflux and those with difficult face-mask ventilation experienced during induction of general anesthesia were excluded from the study. Patients with previously experienced difficult conventional tracheal intubation, anatomic features predictive for difficult conventional laryngoscopy and tracheal intubation [such as limited mouth opening (but not less than 20 mm), restrictions in forward movement of the jaw, reduced thyromental distance, and/or limitations in head and neck movement], and/or obesity were given preferential enrollment into the study. Therefore, this clinical investigation represents data of a prospective, but non-consecutive observational study.

Participating Operators. The operators (voluntary staff anesthetists and anesthesia residents could participate in the study) had no experience with laryngoscopy and tracheal intubation using the Airtraq Optical Laryngoscope (AOL). They first received formal hands-on training on a suitable AM model (AirSim Multi, TruCorp, Belfast, United Kingdom) for acquisition of sufficient skills in handling with the AOL and passing the tracheal tube (TT) through the laryngeal aperture into a midtracheal position, and were then instructed during the first 10 applications on patients (the number for obtaining acceptable clinical performance and competence estimated by the instructor). The study design provided successful AOL-assisted laryngoscopies and tracheal intubations on a maximum of 20 patients.

Experienced Instructor. The instructor (the corresponding author of this clinical investigation) first searched the literature (main findings: 2, 4, 5, 8, 9); in addition, he had personal contact with the inventor of the AOL (Pedro A. Gandarias, Vizcaya, Spain) at a meeting and workshop for AM. He then evaluated and trained AOL-assisted laryngoscopy and tracheal intubation on an AM model (AirSim Multi), before performing the technique on selected patients. After acquiring experience with the AOL and performing an evaluation process, testing the efficacy and safety of the AOL in easy and later in difficult tracheal intubation situations (including more than 20 patients), he initiated the stepwise introduction of the AOL into clinical practice by formal instruction of novice users.

Anesthetic Technique. Patient monitoring and anesthetic care were provided by the S/5 Anesthesia Delivery Unit (Datex-Ohmeda, Instrumentarium Corporation, Helsinki, Finland). Glycopyrrolate 0.2 to 0.4 mg was given 3 min before induction of anesthesia. Following preoxygenation, general anesthesia was induced with 2.5 to 3.5 mg.kg-1 propofol supplemented by 1.5 to 3.0 µg.kg-1 fentanyl. After confirmation of effective face-mask ventilation with oxygen, muscle relaxation was achieved using 0.6 mg.kg-1 rocuronium. During AM, intermittent boluses of propofol were occasionally given at the discretion of the instructor for maintaining an adequate depth of anesthesia.

Conventional Laryngoscopy. After complete neuromuscular blockade [judged by neuromuscular transmission (S/5 Neuromuscular Transmission Module and Mechanosensor, with the electrodes placed over the ulnar nerve using the train-of-four mode)], conventional laryngoscopic view grading (CLV) was performed using direct laryngoscopy with a standard Macintosh laryngoscope for fiberoptic battery handles (Karl Storz Endoscopy, Tuttlingen, Germany; blade sizes 3 and 4 in small and large adults, respectively. The depth of blade insertion was determined by the vallecula; gentle lifting force on the blade was applied and the laryngeal view was evaluated without external laryngeal manipulation. Positioning of the patient regarding elevation of the head and extension of the neck [particularly using the ramped head-elevated laryngoscopy position in obese patients (1)] was at the discretion of the operator when staff anesthetist, otherwise at the discretion of the instructor.

Conventional Laryngoscopic View Grading. The 5-grade modification of the original classification of laryngoscopic views by Cormack and Lehane was used for CLV (10): grade 1, visualization of the entire laryngeal aperture; grade 2, visualization of just the posterior portion of the laryngeal aperture; grade 3, visualization of only the arytenoids; grade 4, visualization of only the epiglottis; and grade 5, visualization of just the soft palate. Laryngoscopy and tracheal intubation with the AOL were then attempted after a short period of face-mask ventilation with oxygen.

Description of the Optical Laryngoscope. The AOL is a disposable device made from medical-grade plastic material. The blade is anatomically shaped and contains a series of lenses, prisms, and mirrors that transfer the image from the illuminated tip of the blade to the view finder at the proximal end of the AOL providing a wide visual field. The blade incorporates a tube-guide channel on the right side to guide the tracheal tube (TT). Light is supplied by alkaline batteries included in the main body of the AOL. The Regular AOL (the blue-coded size 3 model) was used throughout this study; the maximum thickness of the blade is 18 mm and the tube-guide channel may be loaded with TTs up to 8.5 mm inner diameter.

Preparation of the Optical Laryngoscope. The AOL was activated 30 seconds before use by pressing the button located on the left side of the viewfinder which turns on the light and warms up the distal optical system to prevent fogging; the light stops blinking when the anti-fogging mechanism is fully activated. The selected TT (tested for cuff leakage and lubricated with a water-solule lubricant) was then placed into the tube- guide channel aligning the tip of the tube with the distal optical system. The upper surface of the blade was also lubricated without contacting the optical system.

Optical Laryngoscopy. The AOL was inserted in the midline into the oral cavity. The blade was then slided around the tongue into the posterior pharynx; optimum depth of insertion was determined by the vallecula. Before the AOL main body reached the vertical plane, visualization of laryngeal structures was attempted. The blade was occasionally slightly elevated against the dorsal face of the tongue with minimum upward pressure for indirectly lifting the epiglottis.

Optical Laryngoscopic View Grading. Positioning of the patient (as selected for CLV) remained unchanged. The laryngeal views obtained with the AOL were evaluated with the same 5-grade classification as used for CLV using gentle lifting force without external laryngeal manipulation.

Tracheal Intubation Technique. For AOL-assisted tracheal intubation, standard TTs (Lo-Contour Murphy, Mallinckrodt Medical, Athlone, Ireland) with inner diameters of 7.5 and 8.0 mm were used in small and large adults, respectively. With the laryngeal aperture in the center of the view finder, the TT was gently advanced from the position in the tube-guide channel through the laryngeal aperture (under continued view). When the TT impinged on laryngeal structures (the arytenoids or the interarytenoid area), the blade was slightly withdrawn, elevated, and/or turned to the right or left side, and TT advancement was repeated; when further advancement of the TT was impeded (by impinging on the anterior wall of the thyroid cartilage or the anterior thyroid wall), the TT was slightly rotated to the right to facilitate passage into a midtracheal position. After visual confirmation of correct placement, the TT was secured at its proximal end and disengaged from the tube-guide channel, and the AOL was removed by rotating the unit forward back and gently lifting it out of the oral cavity.

Procedure after Failed Tracheal Intubation. When tracheal intubation failed after two separate attempts (duration more than 120 seconds and/or desaturation with oxygen saturations of less than 95 percent), further AM (and the tracheal intubation technique applied) was at the discretion of the operator when staff anesthetist, otherwise at the discretion of the instructor. Between the tracheal intubation attempts, the patients received face-mask ventilation with oxygen to ensure adequate oxygenation.

Disposal of the Optical Laryngoscope. The AOL and the containing alkaline batteries were separately disposed. The view finder was separated from the main body of the AOL and the alkaline batteries were removed by pulling the battery cover away from the main body.

Severe Complaints and Associated with Airway Management. Severe complaints and injuries (to oropharyngeal, laryngeal, and/or tracheal structures) associated with AM were evaluated by the instructor at the postanesthesia care unit and during the postanesthesia visit on the first postoperative day at the normal ward.

Independent Observer. The instructor was also independent observer during the entire study. He documented CLVs and the laryngeal views obtained with the AOL (both rated by the operator) obtained; furthermore, he documented minor problems and difficulties and failures during AM, the procedure(s) applied after failed tracheal intubation, and severe complaints and injuries associated with AM.

Statistics. Statistical analysis was performed using a statistical software program (SAS, version 8.20, SAS Institute Incorporated, Cary, North Carolina, United States). After passing normality test, one way analysis of variance was performed; multiple comparison using the Tukey test followed if the one way analysis of variance showed significance. Results were considered significant at p-values less than 0.05.

Results

Participating Operators. Ten staff anesthetists and two anesthesia residents volunteered and participated in this study. They performed laryngoscopy and tracheal intubation attempts with the Airtraq Optical Laryngoscope (AOL) on from 14 to a maximum of 20 (median: 18) patients. The operators were novice users of the AOL.

Patient Demographics. During April and December 2007, 214 patients requiring orotracheal intubation for elective thyroid surgery were enrolled into this study; none of these patients was excluded from the study because of difficult face-mask ventilation experienced during induction of general anesthesia. The demographic data of the patients according to conventional laryngoscopic view grading (CLV) are summarized in Table 1. Grades 1 to 5 at CLV were obtained in 74, 62, 44, 32, and 2 patients, respectively. There were no statistically significant differences in age, height, weight, male/female ratio, body mass index, and American Society of Anesthesiologists physical status classification between the groups of CLV. The majority of the study patients were female (usual in patients undergoing thyroid surgery).

Table 1. Demographic data of the patients according to conventional laryngoscopic view grading.

Grade 1 Grade 2 Grade 3 Grade 4 Grade 5

Number of 74 62 44 32 2 patients Age (years) 56 (18-93) 53 (18-83) 53 (29-76) 52 (25-81) 54 (40-67) Height (cm) 167 (145-190) 170 (150-186) 168 (156-183) 168 (155-190) 158 (156-160) Weight (kg) 73 (48-108) 72 (50-125) 72 (51-129) 78 (57-103) 58 (45-71) Body mass index 25.2 (18.8-39.0) 25.8 (18.8-42.3) 26.5 (19.5-45.7) 26.9 (21.0-38.7) 23.1 (18.5-27.2) (kg.m-2) Male/female 22/52 14/48 13/31 9/23 2/0 ratio ASA physical 43/27/4 33/28/1 30/11/3 22/10/0 2/0/0 status (1/2/3)

Values for age, height, weight, and body mass index are expressed as median (range). Abbreviation: ASA (American Society of Anesthesiologists).

Laryngeal Views in Patients with the First Attempt of Tracheal Intubation Successful. The success rate of AOL-assisted tracheal intubation at the first attempt was 97 percent (207/214 patients) with laryngeal views of grade 1 in all of these patients. The laryngeal views with the convential laryngoscope were equally distributed between the operators.

Minor Problems and Difficulties in Patients with the First Attempt of Tracheal Intubation Successful. Impeded blade insertion (due to limited mouth opening and/or restricted pharyngeal space) and impeded tracheal tube (TT) advancement (during laryngeal and/or tracheal passage) were encountered in 9 and 12 percent, respectively (see Table 2). There were no problems with poor visibility (due to the presence of secretions and/or fogging of the optical system).

Table 2. Minor problems and difficulties according to conventional laryngoscopic view grading in patients with the first attempt of tracheal intubation successful.

Conventional laryngoscopic view Grade 1 Grade 2 Grade 3 Grade 4 Grade 5 grading Impeded blade insertion

Limited mouth opening 0 0 1 3 2

Restricted pharyngeal space 2 5 3 3 0

Impeded tube advancement

Laryngeal passage 6 5 8 3 0

Tracheal passage 0 0 2 1 0

Causes of Primary Failures of Laryngoscopy and Tracheal Intubation. In 5 patients, the primary failures of AOL-assisted tracheal intubation occured early in the series of individual performance (within the first 10 applications); the causes were failed identification of anatomical structures in one patient with CLV 4 and failed TT advancement during laryngeal passage in one patient with CVL 1, in two patients with CLV 2, and in one patient with CLV 4. In 2 patients with CLV 4, the TT was too large for unimpeded and atraumatic laryngeal passage; downsizing of the TT provided unimpeded laryngeal passage.

Laryngeal Views and Minor Problems and Difficulties in Patients with the Second Attempt of Tracheal Intubation Successful. Seven patients required a second attempt for successful AOL-assisted tracheal intubation with downsizing the TT in two patients. The laryngeal views obtained with the AOL during the second attempt were grade 1 in all patients. Impeded TT advancement during laryngeal passage was encountered in two patients with CVL 4.

Severe Complaints and Injuries Associated with Airway Management. Severe complaints and injuries (to oropharyngeal, laryngeal, and/or tracheal structures) associated with airway management were not observed at the postanesthesia care unit and during the postanesthesia visit on the first postoperative day at the normal ward.

Discussion

In this clinical investigation (including 214 patients), orotracheal intubation with the disposable Airtraq Optical Laryngoscope (AOL), performed by novice but instructed operators (staff anesthetists and anesthesia residents), was successful at the first attempt in 97 percent (with vizualization of the entire laryngeal aperture) in patients with a wide range of conventional laryngoscopy view grading (CLV); in the remaining seven patients, AOL-assisted tracheal intubation was successful after a maximum of two attempts. These favorable results may not be obtained, when novice operators without formal instruction in the technique perform tracheal intubation attempts with the AOL. The primary failures of tracheal intubation in 5 patients were attributed to the inability of identification of laryngeal structures and passage of the tracheal tube (TT) through the laryngeal aperture (both encountered in the early series of individual performance). In 2 patients, the TT had to be downsized for unimpeded and atraumatic laryngeal passage.

The results of our study strongly support the initial use of an airway management (AM) model for formal hands-on training. When the novice users of the AOL performed the first series of laryngoscopy and tracheal intubation attempts on patients, they were already familiar and confident with the technique. The number for obtaining acceptable clinical performance and competence with this device, estimated by the instructor, remained within 10 applications for all operators. The clip-on AOL Video System (instead of the removable view finder) allows viewing of the procedure on a compatible medical monitor (not used in this study); simultaneous viewing by the operator and the instructor (and others) may accelerate the instruction.

The relatively bulky AOL blade may impede blade insertion, particularly in patients with limited mouth opening and/or restricted pharyngeal space (encountered in 9 percent). However, the AOL blade favorably incorportes the tracheal tube (TT) already in the tube-guide channel, eliminating the need for additional space passing the TT through the oral cavity.

The view finder of the AOL allowed visualization of anatomical structures with adequate image quality and provided a panoramic view of the laryngeal aperture when the blade was properly inserted. There were no problems with poor visibility due to fogging of the optical system (by warming-up the system slightly above body temperature within a short period of time); also secretions did not appear to interfere with the laryngeal view because the optical system is protected and remote from the tip of the blade.

The curvature of the tube-guide channel and the orientation of the optical system of the AOL were usually well aligned with the laryngeal aperture; when the laryngeal aperture was in the center of the view finder, advancement of the TT into a midtracheal position was generally successful at the first attempt. Nevertheless, there were minor problems and difficulties with impeded TT passage through the laryngeal aperture in 11 percent (partly attributable to distortion of the larynx, frequently observed in patients undergoing thyroid surgery). When the TT impinged on laryngeal structures (usually on the arytenoid cartilages or the interarytenoid area), a backward, upward, and to the left or right movement of the AOL blade regularly solved this problem. Interestingly, impeded TT advancement during tracheal passage (despite tracheal deviations and/or compressions by enlarged thyroid glands and using standard TTs) was rarely a problem.

Recently, Maharaj and co-workers (3) compared the ease of orotracheal intubation with the Macintosh laryngoscope and the AOL in patients with normal airways (but with manual cervical spine immobilization) in a randomized, controlled clinical study (with 20 patients in both groups). All patients (except one patient in the Macintosh group requiring three attempts) were successfully intubated at the first atttempt; the AOL reduced the duration of the intubation time, the need for additional airway maneuvers, and the intubation conditions. In a case series of 7 patients with difficult conventional laryngoscopy (grade 5, visualization of only the soft palate, despite external laryngeal manipulation) and failed tracheal intubation after multiple attempts, they were sussessful at the first attempt of AOL-assisted orotracheal intubation (with views of the entire laryngeal aperture) (6). We agree with the suggestions of Maharaj and co-workers (6), that the AOL may serve as valuable rescue device in situations of difficult conventional laryngoscopy and failed tracheal intubation; furthermore, we suppose that the AOL may have implications on future updates of the various published recommendations for difficult AM.

Provided formal instruction, success of tracheal intubation with the AOL performed by novice users (staff anesthetists and anesthesia residents) was not affected by CLV. The AOL proved to be uniquely useful for routine and difficult laryngoscopy and tracheal intubation in clinical practice. The AOL may be also useful in medical situations, but this suggestion has to be supported by further studies.

References

1. Collins JS, Lemmens HJ, Brodsky JB, Brock-Utne JG, Levitan R. Laryngoscopy and morbid obesity: a comparison of the "sniff" and "ramped" positions. Obes Surg 14:1171-1175, 2004. 2. Dhonneur G, Ndoko S, Amathieu R, Housseini LE, Poncelet C, Tual L. Tracheal intubation using the AirtraqR in morbid obese patients undergoing emergency Cesarean delivery. 106:629-630, 2007. 3. Maharaj CH, Buckley E, Harte BH, Laffey JG. Endotracheal intubation in patients with cervical spine immobilization. A comparison of Macintosh and Airtraq laryngoscopes. Anesthesiology 107:53-59, 2007. 4. Maharaj CH, Costello JF, Higgins BD, Harte BH, Laffey JG. Learning and performance of tracheal intubation by novice personnel: a comparison of the AirtraqR and Macintosh laryngoscope. Anaesthesia 61:671-677, 2006. 5. Maharaj CH, Costello J, Higgins BD, Harte BH, Laffey JG. Retention of tracheal intubation skills by novice personnel: a comparison of the AirtraqR and Macintosh laryngoscopes. Anaesthesia 62:272-278, 2007. 6. Maharaj CH, Costello JF, McDonnell G, Harte BH, Laffey JG. The AirtraqR as a rescue airway device following failed direct laryngoscopy: a case series. Anaesthesia 62:598-601, 2007. 7. Maharaj CH, Higgins BD, Harte BH, Laffey JG. Evaluation of intubation using the Airtraq or Macintosh laryngoscope by anaesthetists in easy and simulated difficult laryngoscopy - a manikin study. Anaesthesia 61:469-477, 2006. 8. Maharaj CH, Ni Chonghaile M, Higgins BD, Harte BH, Laffey JG. Tracheal intubation by inexperienced medical residents using the Airtraq and Macintosh laryngoscopes - a manikin study. Am J Emerg Med 24:769-774, 2006. 9. Maharaj CH, O'Croinin D, Curley G, Harte BH, Laffey JG. A comparison of tracheal intubation using the AirtraqR or the Macintosh laryngoscope in routine airway management: a randomised, controlled clinical trial. Anaesthesia 61:1093-1099, 2006. 10. Wilson ME, Spiegelhalter D, Robertson JA, Lesser P. Predicting difficult intubation. Br J Anaesth 61:211-216, 1988.

Implications for Clinical Practice

Notice: Implications for Clinical Practice are the personal views of the authors.

Within a short period of time, we became familiar and confident with the use of the Airtraq Optical Laryngoscope (AOL) for orotracheal intubation, particularly in difficult conventional laryngoscopy situations. Despite well equipped with difficult airway carts (or equivalent units), the anesthesia working stations, the positions at the , and the emergency admission area are now additionally supplied with AOLs.

Hygienic reprocessing of reusable airway management (AM) devices may be problematic, particularly after use in patients with transferable diseases. We now routinely use the disposable AOL for tracheal intubation in all patients with transferable infectious diseases; this procedure may further eliminate possible cross contamination associated with AM devices.

The AOL may be also suitable for emergency and internal medicine physicians with far fewer experiences and opportunities in conventional laryngoscopy and tracheal intubation. Within the next months, we will expand our teaching and training activities to emergency and internal medicine residents of our institution in the use of the AOL first on a suitable AM model and then on patients requiring tracheal intubation for elective surgical procedures.

Economic Considerations

Notice: Economic Considerations are the personal views of the authors.

The costs of the disposable Airtraq Optical Laryngoscope (AOL) are about 48 Euro (exclusive value-added taxes, according to the offer of the Austrian distributor of the AOL, queried in March 2007) and allows for this device to be provided at multiple locations within the hospital (including normal wards).