Specialized neurocritical care, severity grade, and outcome of patients with aneurysmal subarachnoid hemorrhage

Introduction: To evaluate the impact of specialized neurocritical care on the population admitted to a neurovascular center and on the outcome of patients with severe aneurysmal subarachnoid hemorrhage (aSAH). Methods: After exclusion of patients treated with endovascular techniques, between 1999 and 2003, 198 patients with aSAH treated with early aneurysm clipping were analysed. In 1999, a new standardized protocol for intensive care treatment was established in the Department of Neurosurgery, University Hospital Zurich. The results were compared to the earlier time period (1993-1994) immediately after introduction of early aneurysm clipping. Results: Out of 198 patients with aSAH, 90 patients (45.5%) suffered from mild aSAH World Federation of Neurosurgical Societies (WFNS) grade 1 and 2,41 (27.3%) from aSAH WFNS grade 3, 36 (18.2%) from grade 4, and 57 (28.8%) from grade 5. From 1999 to 2003, significantly more patients with severe aSAH WFNS grade 4 and 5 underwent (further) treatment (93 out of 198 patients; 47.0%) compared to the former time-period after introduction of early surgery (23 out of 150 patients; 15.3%) (p < 0.0001). In the early series, 10 out of 23 patients (43.5%) with WFNS 4 recovered with good outcome Glasgow Outcome Score 4 and 5, whereas in the later series 23 out of 36 (63.9%) with WFNS grade 4 survived in a good functional state. Before 1999, all patients with WFNS grade 5 died or survived in a vegetative state. From 1999 to 2003, 20 out of 57 patients (35.1%) with aSAH WFNS grade 5 survived with good outcome. Conclusions: The availability of extended specialized neurocritical care seems to induce a change within the patient population towards a higher severity grade. Patients with high-grade aSAH might benefit most from highly specialized neurocritical care treatment.