Table 1 Characteristic of the population with poor grade subarachnoid hemorrhage (SAH) during the four different study periods. Data are presented as mean (\(\pm\)SD), median (IQRs) or counts (%)

Age, years

57 (±14)

60 (± 16)

56 (± 11)

57 (± 14)

54 (± 15)

0.08

Male gender, n (%)

149 (42)

29 (42)

26 (37)

48 (42)

46 (47)

0.57

APACHE score

18 (16–21)

16 (13–19)

18 (15–20)

19 (17–21)

21 (18–24)

< 0.001

SOFA score

8 (5–10)

6 (4–7)

6 (5–9)

8 (6–10)

9 (7–10)

< 0.001

Glasgow coma scale

4 (3–7)

6 (3–10)

7 (3–9)

3 (3–6)

3 (3–6)

< 0.001

WFNS 5, n (%)

239 (68)

34 (49)

38 (54)

92 (79)

75 (77)

< 0.001

Fisher scale 3 or 4 points, n (%)

330 (94)

64 (93)

70 (99)

115 (99)

81 (84)

0.03

Aneurysm, n (%)

288 (82)

54 (78)

56 (79)

93 (80)

85 (88)

0.34

Hypertension, n (%)

146 (41)

35 (51)

19 (27)

51(44)

41(42)

0.03

Diabetes mellitus, n (%)

35 (10)

9 (13)

9 (13)

9 (8)

8 (8)

0.52

Heart disease, n (%)

52 (15)

13 (19)

10 (14)

17 (15)

12 (12)

0.71

Previous neurological disease, n (%)

44 (12)

13 (19)

4 (6)

20 (17)

7 (7)

0.02

Chronic kidney disease, n (%)

7 (2)

1 (1)

0

2 (2)

4 (4)

0.28

COPD, n (%)

27 (8)

4 (6)

5 (7)

8 (7)

10 (10)

0.70

Corticosteroid use, n (%)

13 (4)

1 (1)

3 (4)

4 (3)

5 (5)

0.65

Cancer, n (%)

30 (9)

12 (17)

4 (6)

8 (7)

6 (6)

0.03

Cirrhosis, n (%)

8 (2)

2 (3)

1 (1)

2 (2)

3 (3)

0.85

Alcohol, n (%)

64 (18)

22 (32)

11 (16)

13 (11)

18 (19)

0.005

Smoking, n (%)

79 (22)

35 (51)

5 (7)

20 (17)

19 (20)

< 0.001

Drug abuse, n (%)

22 (6)

15 (22)

1 (1)

3 (3)

3 (3)

< 0.001

Support Therapies

Vasopressor use, n (%)

256 (73)

41 (60)

52 (73)

77 (66)

86 (89)

0.001

Inotropic use, n (%)

55 (16)

1 (1)

9 (13)

14 (12)

31 (32)

< 0.001

ECMO v-v, n (%)

3 (1)

0

0

1 (1)

2 (2)

0.41

Mechanical ventilation, n (%)

321 (91)

59 (86)

65 (92)

108 (93)

89 (92)

0.36

CRRT, n (%)

3 (1)

1 (1)

0

1 (1)

1 (1)

0.82

Neurological monitoring and specific treatments

Surgical treatment (clipping), n (%)

55 (16)

11 (16)

11 (16)

14 (12)

19 (20)

0.52

Endovascular treatment, n (%)

162 (46)

31 (45)

40 (56)

45 (39)

46 (47)

0.13

ICP monitoring, n (%)

264 (75)

49 (71)

56 (79)

80 (69)

47 (49)

0.14

PbtO₂ monitoring, n (%)

49 (14)

0

0

2 (2)

47 (49)

< 0.001

Continuous EEG monitoring, n (%)

220 (63)

42 (61)

52 (73)

62 (53)

64 (66)

0.04

Vasospasm prophylaxis, n (%)

235 (67)

53 (77)

58 (82)

75 (65)

49 (51)

< 0.001

Hyperventilation, n (%)

168 (48)

29 (42)

35 (49)

57 (49)

47 (49)

0.78

Osmotic therapy, n (%)

158 (45)

30 (44)

22 (31)

58 (50)

48 (50)

0.05

Decompressive craniectomy, n (%)

14 (4)

2 (3)

3 (4)

3 (3)

6 (6)

0.56

Barbituric coma, n (%)

68 (19)

13 (19)

13 (18)

21 (18)

21 (22)

0.92

Hypothermia, n (%)

46 (13)

2 (3)

4 (6)

14 (12)

26 (27)

< 0.001

Induced hypertension, n (%)

128 (36)

35 (51)

21 (30)

33 (28)

39 (40)

0.01

Intra-arterial injection of nimodipine, n (%)

37 (11)

1 (1)

7 (10)

6 (5)

23 (24)

< 0.001

Neurological complications

Intraparenchymal hematoma, n (%)

153 (43)

39 (57)

25 (35)

41 (35)

48 (50)

0.01

Seizure, n (%)

94 (27)

14 (20)

26 (37)

26 (22)

28 (29)

0.10

Rebleeding, n (%)

27 (8)

7 (11)

1 (1)

7 (6)

12 (12)

0.05

Hydrocephalus, n (%)

150 (43)

22 (32)

14 (20)

75 (65)

39 (40)

0.001

Delayed cerebral ischemia, n (%)

82 (23)

27 (39)

15 (21)

17 (15)

23 (24)

0.002

Intracranial hypertension, n (%)

230 (65)

48 (70)

42 (59)

80 (69)

60 (62)

0.40

Outcomes

UO, n (%)

260 (74)

51 (74)

50 (70)

85 (73)

90 (77)

0.86

GOS at 3 months, median (IQR)

1 (1–4)

1 (1–4)

2 (1–4)

1 (1–4)

1 (1–3)

0.42

ICU LOS- days, median (IQR)

8 (2–7)

7 (2–15)

10 (3–16)

6 (1–16)

9 (2–21)

0.11

Hospital LOS- days, median (IQR)

13 (2–35)

9 (2–34)

13 (3–35)

10 (1–28)

20 (2–44)

0.06

ICU mortality, n (%)

195 (56)

43 (62)

33 (47)

70 (60)

49 (51)

0.13

Hospital mortality, n (%)

202 (57)

45 (65)

35 (49)

73 (63)

49 (51)

0.07