Peripheral Leukocytosis and Clinical Outcomes After Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (SAH) has a high morbidity rate. Following SAH, a powerful systemic inflammatory response ensues contributing to delayed neurological deterioration and outcome. The aim of this study is to investigate if peripheral leukocytosis following SAH impacts clinical outcomes.

This is a retrospective, observational, single tertiary center study of patients with SAH who underwent microsurgical clipping between 2017 and 2020. The study's inclusion criteria were aneurysmal SAH on baseline computerized tomography (CT), age above 18 years, and hospital admission within 72 hours of bleeding. Traumatic SAH, arteriovenous malformations, and mycotic aneurysms were all excluded. On admission, leukocyte counts were recorded. Demographic and clinical variables were compared between the two groups (TLC ≤12,000 and >12,000). The impact of peripheral leukocytes on clinical outcomes in terms of the Glasgow Outcome Score (GOS) was analyzed. Mann-Whitney U test for continuous variable and Fisher exact test or chi-square test for categorical variables were used for calculation of P-value. A P-value of 0.05 or less was considered statistically significant.

Among 90 patients who underwent clipping of ruptured aneurysms, 40 (44.4%) were anterior communicating artery (ACOMM) aneurysms, and 21 (23.3%) were middle cerebral artery(MCA), and 16 (17.8%) were posterior communicating artery (PCOMM). Clinically 57 patients (63.3%) had a World Federation of Neurosurgical Societies (WFNS) grade 1, 17 patients (18.9%) had a grade 2, four patients (4.4%) had a grade 3, and two patients (2.2%) had a grade 4. On radiological examination, six patients (6.7%) had fisher grade 1, 23 patients (25.6%) had grade 2, 22 patients (24.4%) had grade 3, and 39 (43.4%) had grade 4 SAH distribution. Clinical results were poor in 30 individuals (33.3 %), but good in 60 patients (66.7 %). On admission leukocytosis (>12,000) was seen among 34 (37.8%). Leukocytosis (>12,000) was associated with poor WFNS grade (>2); however, statistical significance was not seen with clinical outcome in terms of GOS.

Poor clinical grade of patients following aneurysmal SAH is associated with peripheral leukocytosis; however, peripheral leukocytosis is not associated with poor outcomes.