Double-lumen tube (DLT) intubation is frequently performed for thoracic surgery, and a fiberoptic bronchoscopy (FOB) can improve the success rate of correct placement. Disposcope endoscope-guided DLT intubation was recently introduced and has a high first-attempt success rate. We tested whether compared with FOB-guided DLT intubation, disposcope endoscope-guided DLT intubation results in a non-inferior first-attempt success rate. A total of 181 patients who underwent thoracic surgery and required DLT intubation were randomly assigned to two groups: FOB guidance (FOB group) and disposcope endoscope guidance (DE group). The primary outcome was the first-attempt success rate. The secondary outcomes included the number of attempts, first intubation time, intraoperative dislodgement, and changes in the mean arterial pressure (MAP) and heart rate (HR) after intubation. The difference in the first DLT attempt success rate between the groups did not exceed the non-inferiority margin of 8% (DE group: 91.3% vs. FOB group: 89.9%
difference: 1.4%, 95% exact CI: -7.1-9.9%). The difference in the number of multiple DLT attempts also did not differ between the DE group and the FOB group (two attempts: 6.5% vs. 6.7%, P = 0.953
three attempts: 2.2% vs. 3.4%, P = 0.120). The first DLT intubation time [66 (55-86) vs. 77 (64-98) s, P = 0.010] was significantly shorter in the DE group. No significant differences were observed in the intraoperative dislodgement or changes in the MAP or HR after intubation (P >
0.05). Compared with FOB guidance, disposcope endoscope guidance provided a non-inferior first-attempt success rate and a shorter first intubation time for DLT intubation.