Results

 

 

Participating Operators. Ten staff anesthetists, 2 anesthesia residents, and 2 qualified anesthesia nurses 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 but instructed users of the AOL. 

 

Patient Demographics. During January and November 2007, 248 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. Laryngeal views of grade 1 to 5 at conventional laryngoscopy (CL) were obtained in 86, 74, 48, 38, 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.

 

Successful Tracheal Intubation at the First Attempt and Minor Problems and Difficulties. The success rate of AOL-assisted tracheal intubation at the first attempt was 97 percent (241/248 patients). Impeded blade insertion due to limited mouth opening and/or restricted pharyngeal space and impeded tracheal tube (TT) advancement during laryngeal passage were encountered in altogether 10 percent and 12 percent, respectively; impeded TT advancement during tracheal passage was rarely a problem (see Table 2). There were no problems with poor visibility due to the presence of secretions and/or fogging of the optical system.

 

Causes of Primary Failures of Laryngoscopy and Tracheal Intubation. In 5 of 7 patients, the primary failures of 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 2 patients with CLV 2, and in 3 patients with CLV 4.

 

Minor Problems and Difficulties in Patients with the Second Attempt of Tracheal Intubation Successful. The remaining 7 patients required a second attempt for successful tracheal intubation with downsizied TTs for atraumatic laryngeal passage in 2 patients. Impeded TT advancement during laryngeal passage was encountered in one patient 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