Table 1 preoperative demographic characteristics of the population

Age (years)

70 [66–74]

71 [64–75]

0.9

Male gender (n, %)

11 (55%)

16 (80%)

0.2

BMI (kg/m²)

25.9 ± 3.9

26.7 ± 4.2

0.5

BMI ≥ 30 kg/m²

6 (30%)

7 (35%)

1

Hypertension

14 (70%)

16 (80%)

0.7

Stroke

1

3

–

Smoking status

9 (45%)

8 (40%)

1

COPD

1

2

–

Obstructive sleep apnea

1

6

–

Preoperative Kidney disease

4

6

0.7

Diabetes

4

8

0.3

Euroscore II (%)

1.6 [1.0–2.3]

1.7 [1.1–2.9]

0.8

NYHA

2 ± 1

2 ± 1

0.8

Preoperative LVEF (%)

65 [51–71]

66 [63–70]

0.3

Type of surgery:

0.08

Coronary artery bypass

11

6

Valvular surgery

8

8

Combined procedures

1

6

Theoretical FRC (mL)

3472 ± 207

3587 ± 173

0.06

Preoperative SpO₂ (%)

95 ± 7

97 ± 2

0.1