Table 3 Trial outcomes

Success rate within 30-sec

33 (49.3%)

58 (86.6%)

< 0.001

Assistance maneuvers

No

26 (38.8%)

47 (70.1%)

0.0037

External laryngeal manipulation

18 (26.9%)

10 (14.9%)

Head extension

13 (19.4%)

6 (9%)

Stylet curvature change

10 (14.9%)

4 (6%)

Anesthetists’ subjective rating of intubation difficulty

Mean

2.7 ± 2

1.27 ± 1.27

< 0.001

Rating score

0

14 (20.9%)

22 (32.8%)

< 0.001

1

9 (13.4%)

21 (31.3%)

2

10 (14.9%)

15 (22.4%)

3

6 (9%)

4 (6%)

4

11 (16.4%)

3 (4.5%)

5

11 (16.4%)

2 (3%)

6

6 (9%)

0

Maneuver-related complications

Dental injury

2 (3%)

1 (1.5%)

0.559

Laryngeal injury

1 (1.5%)

0

0.816

Postoperative sore throat

5 (7.5%)

2 (3%)

0.244

Total

8 (12%)

3 (4.5%)

0.116