Timing of clinical grade assessment and poor outcome in patients with aneurysmal subarachnoid hemorrhage

Abstract

Object Timing of clinical grading has not been fully studied in patients with aneurysmal subarachnoid hemorrhage (SAH). The primary objective of this study was to identify at which time point clinical assessment using the World Federation of Neurosurgical Societies (WFNS) grading scale and the Glasgow Coma Scale (GCS) is most predictive of poor functional outcome. Methods This study is a retrospective cohort study on the association between poor outcome and clinical grading determined at presentation, nadir, and postresuscitation. Poor functional outcome was defined as a Glasgow Outcome Scale score of 1–3 at 6 months after SAH. Results The authors identified 186 consecutive patients admitted to a teaching hospital between January 2002 and June 2008. The patients' mean age (± SD) was 56.9 ± 13.7 years, and 63% were women. Twenty-four percent had poor functional outcome (the mortality rate was 17%). On univariable logistic regression analyses, GCS score determined at presentation (OR 0.80, p < 0.0001), nadir (OR 0.73, p < 0.0001), and postresuscitation (OR 0.53, p < 0.0001); modified Fisher scale (OR 2.21, p = 0.0013); WFNS grade assessed at presentation (OR 1.92, p < 0.0001), nadir (OR 3.51, < 0.0001), and postresuscitation (OR 3.91, p < 0.0001); intracerebral hematoma on initial CT (OR 4.55, p < 0.0002); acute hydrocephalus (OR 2.29, p = 0.0375); and cerebral infarction (OR 4.84, p < 0.0001) were associated with poor outcome. On multivariable logistic regression analysis, only cerebral infarction (OR 5.80, p = 0.0013) and WFNS grade postresuscitation (OR 3.43, p < 0.0001) were associated with poor outcome. Receiver operating characteristic/area under the curve (AUC) analysis demonstrated that WFNS grade determined postresuscitation had a stronger association with poor outcome (AUC 0.90) than WFNS grade assessed upon admission or at nadir. Conclusions Timing of WFNS grade assessment affects its prognostic value. Outcome after aneurysmal SAH is best predicted by assessing WFNS grade after neurological resuscitation.