The rigid nasendoscope as a tool for difficult tracheal intubation: a manikin study

We examined the use of the 30 degrees rigid nasendoscope in aiding difficult tracheal intubations. A Cormack and Lehane grade 4 difficult intubation (no view of glottis or epiglottis) was set up on a manikin. After 10 s of tuition, 40 anaesthetists attempted to pass a standard gum elastic bougie between the cords, with and without the nasendoscope, in randomised order. A bougie curved to an 'optimal curve' was also tested. Using the standard bougie 13/40 (33%) passed the bougie between the cords without the nasendoscope, compared with 31/40 (78%) when using the nasendoscope (p < 0.001). The 'optimal curve' bougie resulted in 29/40 (73%) and 39/40 (98%) success rates without and with the nasendoscope, respectively (p = 0.004). The nasendoscope is a simple and easy to use tool in grade 4 intubation, and results are improved further by the use of an 'optimal curve' bougie.