Symptomatic Venous Thromboembolism: Incidence and Risk Factors in Patients with Spontaneous or Traumatic Intracranial Hemorrhage

The objectives of this study are to determine the incidence of symptomatic venous thromboembolism (VTE) in neurosurgery intensive care unit (NSICU) patients with spontaneous or traumatic intracranial hemorrhage and to identify the common VTE risk factors by injury type. This retrospective, single-center cohort study included adult patients admitted to the NSICU between January 2001 and July 2004 with a primary diagnosis of subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), or traumatic brain injury (TBI). Patients and VTE events were identified using ICD-9 codes. All patients received low-dose unfractionated heparin or enoxaparin and intermittent pneumatic compression device. Descriptive statistics were used to describe patient characteristics. The overall incidence of symptomatic VTE was 3.8% (n = 1195). The incidence of VTE was 6.7% in SAH patients (n = 179), 2.9% in ICH patients (n = 516), and 3.8% in TBI patients (n = 500). The most commonly identified risk factors in the three groups were: greater than 40 years of age, immobility due to paresis or restrictions for mechanical ventilation, presumed infection, and presence of indwelling central venous catheter. There was no objective evidence of intracranial bleeding associated with pharmacologic VTE prophylaxis in VTE patients. This is the first study to determine symptomatic VTE incidence and to identify common risk factors by injury type in nontumor patients who are not routinely screened with venous duplex ultrasonography but receiving early IPC and LDUH. Further studies are needed to determine the overall incident of symptomatic and nonsymptomatic VTE and independent risk factors for VTE events in NSICU patients.