Clinical characteristics of 407 patients with spontaneous SAH admitted to a neurosurgical unit
| Characteristic N (%) | Overall | Hyponatraemia | No hyponatraemia |
| Number of patients | 407 | 175 | 232 |
| Age at diagnosis in years: median (IQR) | 58 (48–66) | 60 (51–68) | 56 (46–65) |
| Female sex | 250 (61%) | 114 (65%) | 136 (59%) |
| Weight in kg: median (IQR) | 73 (64–85) | 71 (61–80) | 76 (65–87) |
| Unknown | 75 (18%) | 27 (15%) | 48 (21%) |
| Previous SAH | 34 (8%) | 17 (10%) | 17 (7%) |
| Unknown | 4 (0.98%) | 0 (0%) | 4 (1.7%) |
| Previous hyponatraemia | 1 (0.3%) | 1 (0.6%) | 0 (0%) |
| Unknown | 4 (0.98%) | 0 (0%) | 4 (1.7%) |
| Hyponatraemia-inducing drugs on admission | |||
| None | 247 (61%) | 104 (59%) | 143 (62%) |
| One | 86 (21%) | 40 (23%) | 46 (20%) |
| Multiple | 73 (18%) | 31 (18%) | 42 (18%) |
| Unknown | 1 (0.3%) | 0 (0%) | 1 (0.4%) |
| WFNS grade | |||
| I | 232 (57%) | 94 (54%) | 138 (59%) |
| II | 57 (14%) | 38 (22%) | 19 (8%) |
| III | 25 (6%) | 11 (6%) | 14 (6%) |
| IV | 47 (12%) | 17 (10%) | 30 (13%) |
| V | 42 (20%) | 13 (7%) | 29 (13%) |
| Unknown | 4 (0.98%) | 2 (1.1%) | 2 (0.9%) |
| Modified Fisher score | |||
| 0 | 13 (3%) | 2 (1.1%) | 11 (5%) |
| 1 | 77 (19%) | 27 (15%) | 50 (22%) |
| 2 | 56 (14%) | 19 (11%) | 37 (16%) |
| 3 | 107 (26%) | 55 (31%) | 52 (22%) |
| 4 | 139 (34%) | 67 (38%) | 72 (31%) |
| Unknown | 15 (4%) | 5 (3%) | 10 (4%) |
| Aneurysm location | |||
| Non-aneurysmal | 104 (26%) | 27 (15%) | 77 (33%) |
| Anterior circulation | 260 (64%) | 120 (69%) | 140 (60%) |
| Posterior circulation | 43 (11%) | 28 (16%) | 15 (7%) |
| Treatment for vascular lesion | |||
| Conservative | 74 (18%) | 17 (10%) | 57 (25%) |
| Open surgical | 48 (12%) | 21 (12%) | 27 (12%) |
| Endovascular | 253 (62%) | 129 (74%) | 124 (53%) |
| Unknown | 32 (8%) | 8 (5%) | 24 (10%) |
SAH, subarachnoid haemorrhage; WFNS, World Federation of Neurosurgical Societies.