Table 1 Patients’ characteristics

Clinical parameters

 Age, years (mean ± SD)

53.03 ± 14.29

60.54 ± 12.89

− 2.560

0.012

 Sex, male/female, n

17/16

33/24

0.344

0.557

 GCS score

7(5,10)

6(5,9)

1.055

0.304^a

 APACHE II

14.33 ± 2.62

16.14 ± 2.68

− 3.130

0.003

 BMI (kg/m²)

25.20 ± 3.21

24.64 ± 2.48

0.927

0.356

 MAP, mmHg

88.42 ± 9.12

90.93 ± 9.16

− 1.253

0.214

Past history, n

χ²

p

 Cardiovascular disease

16

31

0.292

0.589

 Cerebrovascular diseases

3

7

0.013

0.908

 Endocrine diseases

3

3

–

0.665^*

 Kidney diseases

1

4

–

0.648^*

 Respiratory diseases

1

2

–

1.000^*

Comorbidities

χ²

p

  Pulmonary infection

23

30

2.514

0.113

  Central system infection

5

19

3.533

0.060

  Heart failure

1

6

–

0.416^*

Ventilatory parameters

χ²

p

 VT (ml)

558.309 ± 137.59

501.48 ± 118.60

2.348

0.021

 MV (L)

9.43 ± 1.84

9.02 ± 2.06

1.196

0.274^a

 Pmean, cmH₂O

7.49 ± 1.11

7.25 ± 1.23

0.943

0.348

 Peep, cmH₂O

5.28 ± 0.88

5.16 ± 0.95

1.188

0.276^a

 Ppeak, cmH₂O

14.53 ± 3.15

13.43 ± 3.11

1.603

0.112

 EAdi (µV)

4.7(3,7.7)

2.80(1.95,4.15)

11.850

0.001^a

 NVE (ml/µV)

141.85(90.52,212.06)

66.01(44.49,94.79)

21.100

 < 0.001^a

 NME(cm H₂O/µV)

2.57(1.71,4.75)

1.37(1.05,2.02)

13.828

 < 0.001^a

Bleeding site, n

χ²

P

 CPH

18

36

0.646

0.422

 SAH

14

17

1.469

0.225

 IVH

1

4

–

0.648*