Comparing Ease of Endotracheal Intubation Using C Blade and D Blade of CMAC Videolaryngoscope in Patients Undergoing Elective Cervical Spine Surgery

Manual in-line stabilisation is used to immobilise the neck during endotracheal intubation in patients undergoing cervical spine surgery to prevent secondary spinal cord damage. This makes visualisation of the glottis difficult with conventional laryngoscopy which can be overcome with videolaryngoscope. CMAC Videolaryngoscope has the conventional blade (C blade) and the highly angulated D blade which was introduced to aid in difficult airway. This study was done to compare the ease of tracheal intubation using the conventional C blade and the D blade of CMAC videolaryngoscope in patients undergoing cervical spine surgery.

Methodology: After Institutional Ethics Committee approval and obtaining informed consent, 68 patients undergoing elective cervical spine surgery were randomised into 2 groups - C (intubated with C blade) or D (intubated with D blade) (n=34 each) by computer generated randomisation. After induction of general anaesthesia, manual in-line stabilisation of the cervical spine was achieved and intubation was attempted by experienced anaesthesiologist with the C blade or D blade according to the group. The time taken for successful intubation, time taken for optimum glottic visualisation, the number of attempts, additional manouvres required for successful intubation and the incidence of complications were compared.

Inclusion criteria

• Patients with ASA (American Society of Anaesthesiology) grade one and two,
• aged 18 years and older,
• Patients with mouth opening more than two and a half fingers (inter-incisor distance >3cm)

Exclusion criteria

• Patients who were unwilling to be a part of the study,
• patients with any oral pathology, hiatus hernia, pregnant women,
• patients with severe systemic diseases