Pulmonary embolism (PE) is unlikely during early ICU care, but should be considered in the hypoxic, tachycardic, and tachypneic patient. Patients with intracranial, spinal cord, mul­tiple long bone, or pelvic injuries have been found to have deep venous thrombosis (DVT) rates up to 80 % without chemopro­phylaxis and should be started on chemical DVT prophylaxis when injuries permit [Barrera]. While chest radiographs are often normal in appearance, an arterial blood gas may show a respiratory alkalosis with a signifi cant A-a gradient. A 12-lead ECG most commonly is signifi cant for sinus tachycardia and rarely shows the S1 Q3 T3 pattern indicative of right heart strain. A focused transthoracic cardiac ultrasound can be effec­tive at identifying septal bowing, apical right ventricle, and right ventricular dilation, all signs of right heart strain and pos­sibly a large PE [ 39 ]. D-dimer determination is unhelpful in the diagnosis of PE in the acutely injured patient. Defi nitive diag­nosis can be made by contrast computed tomography of the chest utilizing a specifi c pulmonary embolism protocol. Ventilation perfusion scans may be considered in cases where the patient cannot receive IV iodinated contrast material. Initial treatment for PE is anticoagulation with heparin or low-molec­ular-weight heparin. Although patients reach therapeutic anti­coagulation faster on low-molecular-weight heparin, an IV drip of heparin is preferred in the trauma patient at high risk of bleeding as the drip is easily stopped. Inferior vena cava (IVC) fi lters may be utilized in patients with pulmonary embolus and contraindication to anticoagulation or who develop a PE while therapeutically anticoagulated [ 40 ].