Danny Epstein1, Yaacov Freund2, Erez Marcusohn3, Tarek Diab1,4, Erez Klein5, Aeyal Raz6,7, Ami Neuberger6,8,9, Asaf Miller10. 1. Critical Care Division, Rambam Health Care Campus, Haifa, Israel. 2. Ruth and Bruce Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Efron St 1, Haifa, 35254, Israel. yaacov.fr@gmail.com. 3. Department of Cardiology, Rambam Health Care Campus, Haifa, Israel. 4. Department of Neurosurgery, Rambam Health Care Campus, Haifa, Israel. 5. Department of Diagnostic Imaging, Rambam Health Care Campus, Haifa, Israel. 6. Ruth and Bruce Rappaport Faculty of Medicine, Technion Israel Institute of Technology, Efron St 1, Haifa, 35254, Israel. 7. Department of Anesthesiology, Rambam Health Care Campus, Haifa, Israel. 8. Infectious Diseases Unit, Rambam Health Care Campus, Haifa, Israel. 9. Department of Internal Medicine B, Rambam Health Care Campus, Haifa, Israel. 10. Medical Intensive Care Unit, Rambam Health Care Campus, Haifa, Israel.
Abstract
BACKGROUND: Spontaneous subarachnoid hemorrhage (SSAH) is associated with significant morbidity and mortality. Pathophysiological processes following initial bleeding are complex and not fully understood. In this study, we aimed to determine whether a low level of ionized calcium (Ca++), an essential cofactor in the coagulation cascade and other cellular processes, is associated with adverse neurological outcome, development of early hydrocephalus, and symptomatic vasospasm among patients with SSAH. METHODS: This was a retrospective single-center cohort study of all patients admitted for SSAH between January 1, 2009, and April 31, 2020. The primary outcome was an unfavorable neurological status at discharge, defined as a modified Rankin Scale score greater than or equal to 3. Secondary outcomes were the development of early hydrocephalus and symptomatic vasospasm. Multivariable logistic regression was performed to determine whether Ca++ was an independent predictor of these outcomes. RESULTS: A total of 255 patients were included in the final analysis. Hypocalcemia, older age, admission Glasgow Coma Scale (GCS) score, and admission Hunt-Hess classification scale (H&H) grades IV and V were independently associated with unfavorable neurological outcome, with adjusted odds ratios (ORs) of 1.93 (95% confidence interval [CI] 1.1-3.4; p = 0.02) for each 0.1 mmol L-1 decrease in the Ca++ level, 1.04 (95% CI 1.01-1.08; p = 0.02) for each year increase, 0.82 (95% CI 0.68-0.99; p = 0.04), and 6.29 (95% CI 1.14-34.6; p = 0.03), respectively. Risk factors for the development of hydrocephalus were hypocalcemia and GCS score, with ORs of 1.85 (95% CI 1.26-2.71; p = 0.002) for each 0.1 mmol L-1 decrease in the Ca++ level and 0.83 (95% CI 0.73-0.94; p = 0.005), respectively. Ca++ was not associated with symptomatic vasospasm (OR 1.04 [95% CI 0.76-1.41]; p = 0.81). Among patients with admission H&H grade I-III bleeding, hypocalcemia was independently associated with unfavorable neurological outcome at discharge, with an adjusted OR of 1.99 (95% CI 1.03-3.84; p = 0.04) for each 0.1 mmol L-1 decrease in the Ca++ level. Hypocalcemia was also an independent risk factor for the development of early hydrocephalus, with an adjusted OR of 2.95 (95% CI 1.49-5.84; p = 0.002) for each 0.1 mmol L-1 decrease in the Ca++ level. Ca++ was not associated with symptomatic vasospasm. No association was found between Ca++ and predefined outcomes among patients with admission H&H grade IV and V bleeding. CONCLUSIONS: Our study shows that hypocalcemia is associated with worse neurological outcome at discharge and development of early hydrocephalus in endovascularly treated patients with SSAH. Potential mechanisms include calcium-induced coagulopathy and higher blood pressure. Trials are needed to assess whether correction of hypocalcemia will lead to improved outcomes.
BACKGROUND: Spontaneous subarachnoid hemorrhage (SSAH) is associated with significant morbidity and mortality. Pathophysiological processes following initial bleeding are complex and not fully understood. In this study, we aimed to determine whether a low level of ionized calcium (Ca++), an essential cofactor in the coagulation cascade and other cellular processes, is associated with adverse neurological outcome, development of early hydrocephalus, and symptomatic vasospasm among patients with SSAH. METHODS: This was a retrospective single-center cohort study of all patients admitted for SSAH between January 1, 2009, and April 31, 2020. The primary outcome was an unfavorable neurological status at discharge, defined as a modified Rankin Scale score greater than or equal to 3. Secondary outcomes were the development of early hydrocephalus and symptomatic vasospasm. Multivariable logistic regression was performed to determine whether Ca++ was an independent predictor of these outcomes. RESULTS: A total of 255 patients were included in the final analysis. Hypocalcemia, older age, admission Glasgow Coma Scale (GCS) score, and admission Hunt-Hess classification scale (H&H) grades IV and V were independently associated with unfavorable neurological outcome, with adjusted odds ratios (ORs) of 1.93 (95% confidence interval [CI] 1.1-3.4; p = 0.02) for each 0.1 mmol L-1 decrease in the Ca++ level, 1.04 (95% CI 1.01-1.08; p = 0.02) for each year increase, 0.82 (95% CI 0.68-0.99; p = 0.04), and 6.29 (95% CI 1.14-34.6; p = 0.03), respectively. Risk factors for the development of hydrocephalus were hypocalcemia and GCS score, with ORs of 1.85 (95% CI 1.26-2.71; p = 0.002) for each 0.1 mmol L-1 decrease in the Ca++ level and 0.83 (95% CI 0.73-0.94; p = 0.005), respectively. Ca++ was not associated with symptomatic vasospasm (OR 1.04 [95% CI 0.76-1.41]; p = 0.81). Among patients with admission H&H grade I-III bleeding, hypocalcemia was independently associated with unfavorable neurological outcome at discharge, with an adjusted OR of 1.99 (95% CI 1.03-3.84; p = 0.04) for each 0.1 mmol L-1 decrease in the Ca++ level. Hypocalcemia was also an independent risk factor for the development of early hydrocephalus, with an adjusted OR of 2.95 (95% CI 1.49-5.84; p = 0.002) for each 0.1 mmol L-1 decrease in the Ca++ level. Ca++ was not associated with symptomatic vasospasm. No association was found between Ca++ and predefined outcomes among patients with admission H&H grade IV and V bleeding. CONCLUSIONS: Our study shows that hypocalcemia is associated with worse neurological outcome at discharge and development of early hydrocephalus in endovascularly treated patients with SSAH. Potential mechanisms include calcium-induced coagulopathy and higher blood pressure. Trials are needed to assess whether correction of hypocalcemia will lead to improved outcomes.