Table 1 Patient characteristics

Male

102 (62.6%)

92 (70.2%)

0.169

1.41

0.86 to 2.30

Body mass index (median)

28.7

28.0

0.411

Age (median)

63.0

64.0

0.824

Preoperative β-blockers

99 (60.7%)

93 (71.0%)

0.66

1.58

0.97 to 1.88

Current smoker

11 (6.7%)

10 (7.6%)

0.77

1.14

0.47 to 2.78

Former smoker

68 (41.7%)

64 (48.9%)

0.221

1.34

0.84 to 2.12

Chronic pain

17 (10.4%)

7 (5.3%)

0.113

0.49

0.20 to 1.21

Stroke/transient ischemic attack

11 (6.7%)

8 (6.1%)

0.824

0.90

0.35 to 2.30

Diabetes mellitus

48 (29.4%)

30 (22.9%)

0.206

0.71

0.42 to 1.21

Renal failure

25 (15.3%)

33 (22.9%)

0.098

1.64

0.91 to 2.96

Asthma

10 (6.3%)

8 (6.2%)

0.986

0.99

0.38 to 2.60

Sleep apnea

50 (30.9%)

34 (26.2%)

0.377

0.79

0.48 to 1.33

w/ CPAP

16 (9.8%)

14 (10.7%)

0.806

1.10

0.52 to 2.34

Lung disease

109 (66.9%)

89 (67.9%)

0.846

1.05

0.64 to 1.72

Dyspnea

101 (62.0%)

83 (63.4%)

0.806

1.06

0.66 to 1.71

Pulmonary hypertension

16 (9.8%)

14 (10.7%)

0.806

1.10

0.52 to 2.34

Chronic obstructive pulmonary disease

14 (8.4%)

13 (9.2%)

0.971

Other lung disease

7 (4.3%)

11 (8.4%)

0.145

2.04

0.77 to 5.43

Cardiovascular disease

153 (93.9%)

125 (95.4%)

0.559

1.36

0.48 to 3.85

Valvular heart disease

94 (57.7%)

73 (55.7%)

0.738

0.92

0.58 to 1.47

Coronary artery disease

80 (49.1%)

73 (55.7%)

0.257

1.31

0.82 to 2.07

Congestive heart failure

42 (25.8%)

32 (24.4%)

0.793

0.93

0.55 to 1.58

Dysrhythmia

37 (22.7%)

31 (23.7%)

0.845

1.06

0.61 to 1.82

Angina

35 (21.5%)

33 (25.2%)

0.452

1.23

0.71 to 2.12

Myocardial infarction

30 (18.4%)

28 (21.4%)

0.525

1.21

0.68 to 2.14

Orthopnea

14 (8.6%)

5 (3.8%)

0.098

0.42

0.15 to 1.21

Peripheral vascular disease

6 (3.7%)

9 (6.9%)

0.217

1.93

0.67 to 5.57

Endocarditis

6 (3.7%)

6 (4.6%)

0.699

1.26

0.40 to 3.99

Ejection fraction

<30

11 (6.7%)

10 (7.8%)

0.947^*

30-50

37 (22.7%)

29 (22.5%)

>50

115 (70.6%)

90 (69.8%)

Airway

Previous difficult intubation

0

0

0

Limited mouth opening

3 (1.8%)

5 (3.8%)

0.301

2.12

0.50 to 9.02

Limited thyromental distance

12 (7.4%)

8 (6.1%)

0.671

0.82

0.32 to 2.07

Limited neck flexion

1 (0.6%)

2 (1.4%)

0.627

Limited neck extension

16 (9.6%)

14 (9.9%)

0.627

Limited jaw protrusion

18 (11.0%)

11 (8.4%)

0.335

Intraoperative view grade 3 or 4

8 (5.0%)

3 (2.4%)

0.254

Intraoperative mask grade 3 or 4

6 (3.7%)

5 (3.8%)

0.960