Comparison of assessment of vocal cord mobility following thyroid surgery using Macintosh Laryngoscope and Airtraq

Introduction: Vocal cord assessment after thyroidectomy, routinely performed by anaesthesiologist by direct laryngoscopy in the immediate postoperative period is associated with significant haemodynamic changes and patient discomfort. Aim: Comparison of patient comfort, haemodynamic response and accuracy of assessment of vocal cord mobility between Airtraq and Macintosh laryngoscope. Methodology: In a prospective, randomised controlled study, 82 euthyroid patients, ASA PS 1-2, aged 20-60 years, of either gender undergoing thyroidectomy under general anaesthesia were randomised to one of two groups, Group M and Group A. Anaesthesia was induced with propofol and fentanyl, maintained with morphine, vecuronium, nitrous oxide and isoflurane in oxygen to maintain a MAC of 1-1.3%. At the end of surgery, patients were extubated after complete reversal of neuromuscular blockade and when fully awake. Vocal cord movement and haemodynamic changes were assessed three minutes later using either Airtraq (Group A) or Macintosh laryngoscope (Group M). Patient reactivity score (Favourable - No grimace or facial grimace; Unfavourable – Any head, neck and limb movements or cough). Vocal cord movements were again assessed by an ENT surgeon 48 hours later. Results: Demographic data, type and duration of surgery were similar in both groups. 63.4% of patients in Group A had favourable scores compared to 29.3% in Group M even though duration of laryngoscopy was longer in Group A. There was no significant difference in haemodynamic changes between the groups. Conclusion: Patients are more comfortable during vocal cord assessment with Airtraq laryngoscopy even though duration of laryngoscopy is longer when compared to Macintosh laryngoscope.