Table 1 Patients’ background variables and anesthesia providers’ characteristics for each of saline and rocuronium groups

Number of subjects

21

17

Gender (male (%), female (%))

(11 (52), 10 (48))

(12 (71), 5 (29)

Age (years)

59 (45,71)

58 (52, 68)

Height (m)

1.64 (1.54, 1.69)

1.66 (1.54, 1.72)

Weight (kg)

61.8 (56.2, 71.6)

62.2 (54.5, 78.5)

Body mass index (kg m⁻²)

23.0 (21.5, 26.3)

23.4 (21.5, 28.2)

Neck circumference (cm)

37.5 (34.0, 40.8)

39.0 (35.5, 42.0)

Mallampati class (1 (%), 2 (%), 3 (%), 4 (%))

(10 (48), 7 (33), 3 (14), 1 (5))

(7 (41), 7 (41), 2 (12), 1 (6))

Inter-incisor distance (mm)

46 (40, 50)

50 (42.5, 50.0)

Thyromental distance (mm)

70 (70, 80)

70 (60, 80)

Upper lip bite test (1 (%), 2 (%), 3 (%))

(21 (100), 0 (0), 0 (0))

(12 (71), 5 (29), 0 (0))

ASA Physical Status (1 (%), 2 (%))

(6 (29), 15 (71))

(2 (12), 15 (88))

Apnoea hypopnoea index (hour⁻¹)

4.6 (2.0, 22.9)

20.5 (1.5, 37.7)

Number of patients with moderate obstructive sleep apnea: n (%)

5 (24)

5 (29)

Number of patients with severe obstructive sleep apnea: n (%)

2 (10)

5 (29)

Anesthesia providers’ experience (years)

1 (1, 6)

6 (1, 9)

Number of providers with uncertified anesthesiologists: n (%)

12 (57)

6 (35)

Number of certified anesthesiologists: n (%)

9 (43)

11 (65)