Comparison of various video laryngoscopes for nasotracheal intubation in simulated difficult airway scenarios: a randomized self-controlled crossover trial

Background: Nasotracheal intubation (NTI) is particularly challenging in patients with rigid neck or micrognathia. Advancements in video laryngoscopy may improve NTI outcomes. We compared performance of direct laryngoscope (DL), King Vision videolaryngoscope (KVL), and C-MAC videolaryngoscope (VL) in normal, rigid neck, and micrognathia airway. Methods: A randomized, self-controlled crossover trial was conducted with 20 anesthesiologists who performed NTI on a high-fidelity mannequin under three airway conditions. Device order was randomized using a computer-generated sequence, and outcome assessors were blinded to the sequence of devices used. Primary outcomes were time to glottic view and intubation. Secondary outcomes included ease of intubation and force on incisors. Results: The median difference (95%CI) in time to intubation suggested that CMAC was better than KVL in normal airway (–9.0[–13.0 to–6.0], p < 0.001), rigid neck (–12.0[–18.0 to –6.5], p < 0.001) and micrognathia (–16.5[–20.0 to –13.5], p < 0.001). When compared to DL, CMAC was better for micrognathia (–8.0[–5.5 to–10.5], p = 0.001) but comparable for normal airway and rigid neck. C-MAC also exerted the least force on incisors, minimizing dental trauma. Conclusion: The C-MAC VL demonstrated superior performance across all airway conditions, offering faster, safer, and easier NTI, making it the preferred device in challenging scenarios. Trial registration: Clinical Trial Registry of India: (CTRI/2022/05/042821) www.ctri.nic.in.