A 68-year-old man with a history of hypertension, type 2 diabetes mellitus, and coronary artery disease presents to the emergency department at 6:45 pm with sudden onset of right-sided weakness and difficulty swallowing and speaking. The patient's wife reports that the symptoms started at 6 pm. He was last noticed to be asymptomatic at 5 pm. He was brought to the emergency department by family members.
On arrival to the emergency department, his vital signs were as follows: blood pressure 180/100 mm Hg, heart rate 120 bpm, and respiratory rate 6 to 8 breaths/min. He had flaccid right upper and lower extremities. An emergent computed tomography (CT) scan of the head did not show an acute intracranial hemorrhage. Tissue plasminogen activator (tPA) was given per protocol and he was admitted to the intensive care unit (ICU).
What is the risk of venous thromboembolism in this patient?
Venous thromboembolism (VTE) is a common preventable complication in hospitalized patients. It includes a spectrum of disease, such as deep venous thrombosis (DVT) and pulmonary embolism (PE). General risk factors for DVT were first described by Virchow in the 19th century.1 These include stasis, vascular wall abnormalities, and a hypercoagulable state; dynamic interaction between these factors leads to thrombosis (Figure 38-1).
The incidence of VTE is thought to be in excess of 600,000 cases per year in the United States.2 The incidence of VTE is even higher in critically ill patients. In a prospective ultrasound study, DVT was detected in 33% of patients admitted to a medical ICU.3 VTE carries a significant risk of morbidity and mortality. Most studies have shown that 15% to 20% of patients with PE have cardiovascular or respiratory compromise manifested by shock, syncope, respiratory distress, or hypoxemia.4, 5
Most of the acute neurologic disorders often put patients in periods of prolonged immobilization, thus placing them at the highest risk for VTE. This is particularly true for patients with acute ischemic stroke and spinal cord injury. Studies that used I125 fibrinogen as a screening method in patients with acute hemiplegic stroke have shown that the incidence of DVT is approximately 50% in the first 2 weeks in the absence of heparin prophylaxis.6 The majority of these deep vein thromboses are asymptomatic and affect a paralyzed leg. The peak incidence of DVT is between day 2 and day 7.7 The incidence of PE in patients with ischemic stroke has been estimated to be between 0.8% and 13%.8, 9 Mortality rate of untreated PE in unselected hospital patients is up to 30%.10 One study has suggested that mortality rate of PE is even higher in patients with acute stroke.11 The incidence of VTE in other neurocritical care conditions ...