Effectiveness of standard direct laryngoscopy with a Macintosh blade, the McGrath videolaryngoscope, and the Airtraq optical laryngoscopes for assessment of vocal cord mobility following thyroid surgery

Abstract

BackgroundAccurate and timely evaluation of vocal cord function following thyroid surgery relieves the stress of both surgeon and anesthesiologist along with optimizing ongoing management. Conventional direct laryngoscopy is the commonly used tool for vocal cord assessment during extubation in thyroid surgeries. Videolaryngoscopes, are not well researched as an equipment to prognosticate extubation in thyroid surgery. Appropriate visualization and assessment of vocal cords during extubation with videolaryngoscopes can be useful for record keeping and documentation. This study was therefore conducted to compare the conventional direct laryngoscopy with prototypes of channeled and non-channeled videolaryngoscopes – Airtraq and McGrath respectively for extubation in thyroid surgery. ObjectiveThe aim of the study was to compare laryngoscopic view, vocal cord mobility during extubation after thyroid surgeries and to assess patient comfort during laryngoscopy. MethodsFollowing approval from the Institutional Ethics board and informed consent from the patients, a prospective randomised study was conducted in 66 patients. Patients posted for elective thyroid surgery were recruited and followed a routine anaesthesia protocol for intubation. Towards the end of surgery dexmedetomidine infusion was started and patients appropriately reversed. Depending on the group, allotted patients underwent laryngoscopy either with standard direct laryngoscope with the Macintosh blade, McGrath MAC blade 3, or Airtraq size 3 optical laryngoscope. During laryngoscopy Cormack-Lehane grading, vocal cord mobility and patient reactivity were assessed and patients were extubated. ResultsGlottic visualization as assessed by the Cormack-Lehane grades were comparable among the three groups. Change in the Cormack-Lehane grading when compared with the one at the time of intubation was better with Airtraq than the other two groups with a p value of 0.023. The patient reactivity score was statistically significant between the groups (p = 0.006), and Airtraq scored better. The Ramsay sedation scores at different time intervals was not significant between the groups. Vocal cord mobility grading and complications were not different between the three groups. ConclusionVideolaryngoscopes provide a better glottic view during extubation with better patient reactivity scores. Airtraq outperformed standard laryngoscope and McGrath having better Cormack-Lehane grades and a better patient reactivity score.