Comparison of tracheal intubation using the Airtraq ® and Mc Coy laryngoscope in the presence of rigid cervical collar simulating cervical immobilisation for traumatic cervical spine injury

BACKGROUND: It is difficult to visualise the larynx using conventional laryngoscopy in the presence of cervical spine immobilisation. Airtraq(®) provides for easy and successful intubation in the neutral neck position. OBJECTIVE: To evaluate the effectiveness of Airtraq in comparison with the Mc Coy laryngoscope, when performing tracheal intubation in patients with neck immobilisation using hard cervical collar and manual in-line axial cervical spine stabilisation. METHODS: A randomised, cross-over, open-labelled study was undertaken in 60 ASA I and II patients aged between 20 and 50 years, belonging to either gender, scheduled to undergo elective surgical procedures. Following induction and adequate muscle relaxation, they were intubated using either of the techniques first, followed by the other. Intubation time and Intubation Difficulty Score (IDS) were noted using Mc Coy laryngoscope and Airtraq. The anaesthesiologist was asked to grade the ease of intubation on a Visual Analogue Scale (VAS) of 1-10. Chi-square test was used for comparison of categorical data between the groups and paired sample t-test for comparison of continuous data. IDS score and VAS were compared using Wilcoxon Signed ranked test. RESULTS: The mean intubation time was 33.27 sec (13.25) for laryngoscopy and 28.95 sec (18.53) for Airtraq (P=0.32). The median IDS values were 4 (interquartile range (IQR) 1-6) and 0 (IQR 0-1) for laryngoscopy and Airtraq, respectively (P=0.007). The median Cormack Lehane glottic view grade was 3 (IQR 2-4) and 1 (IQR 1-1) for laryngoscopy and Airtraq, respectively (P=0.003). The ease of intubation on VAS was graded as 4 (IQR 3-5) for laryngoscopy and 2 (IQR 2-2) for Airtraq (P=0.033). There were two failures to intubate with the Airtraq. CONCLUSION: Airtraq improves the ease of intubation significantly when compared to Mc Coy blade in patients immobilised with cervical collar and manual in-line stabilisation simulating cervical spine injury.