Retrograde light-guided laryngoscopy for tracheal intubation: clinical practice and comparison with conventional direct laryngoscopy.

BACKGROUND Tracheal intubation with conventional laryngoscopy requires many trials until beginners are sufficiently skilled in intubating patients safely. To facilitate intubation, the authors used retrograde light-guided laryngoscopy (RLGL) and compared its feasibility with conventional direct laryngoscopy (DL). METHODS Twenty operators participated in a prospective, randomized, open-label, parallel-arm study. These operators intubated 205 patients randomly according to a computer-generated procedure by using either DL or RLGL (five intubations with each technique). The primary outcome was the success rate of tracheal intubation. The authors evaluated the success rate of tracheal intubation, the time to glottic exposure and tracheal intubation, and the Cormack and Lehane grades. RESULTS Compared with DL, the success rate was greater in the RLGL group for all five intubations (72% vs. 47%; rate difference, 25%; 95% CI [11.84-38.16%], P < 0.001). This was associated with a shorter time to glottic exposure (median [25th and 75th percentile]; 27 [15; 42] vs. 45 [30; 73] s, P < 0.001), shorter intubation time (66 [44; 120] vs. 120 [69; 120] s, P < 0.001), and decreased throat soreness (mean ± SD; visual analog scale, 2.1 ± 0.9 vs. 3.7 ± 1.0 cm, P = 0.001) in the RLGL group compared to the DL group. CONCLUSION RLGL is an alternative intubation technique. In our study, it enables beginners to intubate patients more successfully and quickly than conventional DL.