Comparison of C-MAC D-blade videolaryngoscope and McCoy laryngoscope efficacy for nasotracheal intubation in simulated cervical spinal injury: a prospective randomized comparative study

BACKGROUND: Immobilization with cervical spine worsens endotracheal intubation condition. Though various intubation devices have been demonstrated to perform well in oral endotracheal intubation, limited information is available concerning nasotracheal intubation (NTI) in patients with cervical spine immobilization. The present study compared the performance of the C-MAC D-Blade videolaryngoscope with the McCoy laryngoscope for NTI in patients with simulated cervical spine injuries. METHODS: This was a prospective, randomized, controlled, study done in a tertiary hospital. Ninety-five patients requiring NTI were included in data analysis: McCoy group (group M, n = 47) or C-MAC D-Blade videolaryngoscope group (group C, n = 48). A Philadelphia neck collar was applied before anesthetic induction to immobilize the cervical spine. Single experienced anesthesiologist performed NTI. The primary outcome was duration of intubation divided by three steps: nose to oropharynx; oropharynx into glottic inlet; and glottic inlet to trachea. Secondary outcomes included glottic view as percentage of glottis opening (POGO) score and Cormack-Lehance (CL) grade, modified nasal intubation-difficulty scale (NIDS) rating, hemodynamic changes before and after intubation, and complications. RESULTS: Total intubation duration was significantly shorter in group C (39.5 ± 11.4 s) compared to group M (48.1 ± 13.9 s). Group C required significantly less time for glottic visualization and endotracheal tube placement in the trachea. More patients in group C had CL grade I and higher POGO scores (P < 0.001, for both measures). No difficulty in NTI (modified NIDS = 0) was more in group C than group M. Hemodynamic changes and incidence of complications were comparable between groups. CONCLUSION: The C-MAC D-Blade videolaryngoscope is an effective tool for NTI in a simulated difficult airway, which improves glottic visualization and shortens intubation time relative to those with McCoy laryngoscope. TRIAL REGISTRATION: Clinical Research Information Service of the Korea National Institute of Health, Identification number: KCT 0004535, Registered December 10, 2019, Retrospectively registered, http://cris.nih.go.kr.