Pharmacologic Venous Thromboembolism Prophylaxis in Patients with Nontraumatic Subarachnoid Hemorrhage Requiring an External Ventricular Drain

Chidozie Ukpabi; Ofer Sadan; Yuyang Shi; Kristy N Greene; Owen Samuels; Subin Mathew; Justin Joy; Yajun Mei; William Asbury

doi:10.1007/s12028-024-01993-5

Pharmacologic Venous Thromboembolism Prophylaxis in Patients with Nontraumatic Subarachnoid Hemorrhage Requiring an External Ventricular Drain

Neurocrit Care. 2024 May 10. doi: 10.1007/s12028-024-01993-5. Online ahead of print.

Authors

Chidozie Ukpabi¹, Ofer Sadan², Yuyang Shi³, Kristy N Greene⁴, Owen Samuels², Subin Mathew⁵, Justin Joy⁶, Yajun Mei³, William Asbury⁶

Affiliations

¹ Department of Clinical Pharmacy, Emory Healthcare, Atlanta, GA, USA. Chidozie.ukpabi@emoryhealthcare.org.
² Division of Neurocritical Care, Department of Neurology and Neurosurgery, Emory University School of Medicine, Atlanta, GA, USA.
³ H. Milton Stewart School of Industrial and Systems Engineering, Georgia Institute of Technology, Atlanta, GA, USA.
⁴ Department of Pharmacy, Emory University Hospital Midtown, Atlanta, GA, USA.
⁵ University of Nebraska Medical Center, Omaha, NE, USA.
⁶ Department of Clinical Pharmacy, Emory Healthcare, Atlanta, GA, USA.

PMID: 38730118
DOI: 10.1007/s12028-024-01993-5

Abstract

Background: Optimal pharmacologic thromboprophylaxis dosing is not well described in patients with subarachnoid hemorrhage (SAH) with an external ventricular drain (EVD). Our patients with SAH with an EVD who receive prophylactic enoxaparin are routinely monitored using timed anti-Xa levels. Our primary study goal was to determine the frequency of venous thromboembolism (VTE) and secondary intracranial hemorrhage (ICH) for this population of patients who received pharmacologic prophylaxis with enoxaparin or unfractionated heparin (UFH).

Methods: A retrospective chart review was performed for all patients with SAH admitted to the neurocritical care unit at Emory University Hospital between 2012 and 2017. All patients with SAH who required an EVD were included.

Results: Of 1,351 patients screened, 868 required an EVD. Of these 868 patients, 627 received enoxaparin, 114 received UFH, and 127 did not receive pharmacologic prophylaxis. VTE occurred in 7.5% of patients in the enoxaparin group, 4.4% in the UFH group (p = 0.32), and 3.2% in the no VTE prophylaxis group (p = 0.08). Secondary ICH occurred in 3.83% of patients in the enoxaparin group, 3.51% in the UFH group (p = 1), and 3.94% in the no VTE prophylaxis group (p = 0.53). As steady-state anti-Xa levels increased from 0.1 units/mL to > 0.3 units/mL, there was a trend toward a lower incidence of VTE. However, no correlation was noted between rising anti-Xa levels and an increased incidence of secondary ICH. When compared, neither enoxaparin nor UFH use was associated with a significantly reduced incidence of VTE or an increased incidence of ICH.

Conclusions: In this retrospective study of patients with nontraumatic SAH with an EVD who received enoxaparin or UFH VTE prophylaxis or no VTE prophylaxis, there was no statistically significant difference in the incidence of VTE or secondary ICH. For patients receiving prophylactic enoxaparin, achieving higher steady-state target anti-Xa levels may be associated with a lower incidence of VTE without increasing the risk of secondary ICH.

Keywords: Aneurysms/subarachnoid hemorrhage; Anticoagulation; Cerebrospinal fluid drainage; Coagulation; Deep vein thrombosis; Enoxaparin; Hydrocephalus; Intracranial pressure; Intraventricular hemorrhage; Neurocritical care; Neurosurgery; Pharmacology; Venous thromboembolism.