Clinical outcome of high-grade aneurysmal acute subarachnoid hemorrhage: Hunt and Hess grade 4 survivors may have a good long-term functional outcome

Abstract

Introduction

Patients with high-grade aneurysmal subarachnoid hemorrhage (SAH) have classically been known to have poor functional outcomes. However, recent reports vary widely in citing the morbidity and mortality for these patients, with some studies citing that the majority of high-grade SAH will gain independent function. The authors sought to clarify functional outcomes expected of high-grade SAH through its own retrospective review as well as a review of the literature.

Methods

A retrospective review was conducted of patients with high-grade SAH managed at a single institution between May 2015 and April 2020. High-grade SAH was defined using the Hunt-Hess (HH) scale 4 or 5 at admission. The primary outcome measures were functional outcome at discharge and at 90 days after discharge, defined using the modified Rankin Scale (mRS). Poor functional outcome was defined as mRS > 3. Additionally, a PubMed search was performed to identify functional outcomes expected of high-grade SAH patients.

Results

Thirty-eight out of the total 229 (16.59 %) SAH patients treated at our center were included in this study. This included 24 (63.16 %) HH grade 4 patients and 14 (36.84 %) HH grade 5 patients. 22 out of 38 patients (57.9 %) survived during the initial admission and were successfully discharged from the hospital. A large majority (n = 20/22, 90.9 %) of patients had poor functional outcomes at the time of discharge, including four patients with mRS 4 and 16 patients with mRS 5. However, two patients (9.1 %) had favorable functional outcomes (mRS 3) at the time of discharge. Notably, 47.1 % of HH4 survivors with poor discharge mRS (8 of 17 patients) improved to mRS ≤ 3 during follow-up. Among the HH grade 5 patients (n = 14), only five patients survived the acute clinical course and subsequently got discharged from the hospital (n = 5/14, 35.7 %).

Conclusion

This investigation provides support that functional outcomes remain poor in high-grade SAH patients. However, there is a large lack of consistency of functional outcomes reported for high-grade SAH among the literature. Of those high-grade SAH that do survive, there is evidence to suggest improvement in functional outcome over time. Longitudinal investigations tracking high grade SAH are warranted.