Which of the following is NOT a clinical sign of PE?

A positive lower extremity venous ultrasound is not considered a clinical sign of pulmonary embolism (PE). Instead, this test is primarily used to diagnose deep vein thrombosis (DVT), which can be a contributing factor to the development of PE.

In patients with PE, the most common clinical signs include chest pain, which may be sharp or pleuritic, dyspnea, which is characterized by difficulty breathing or shortness of breath, and tachycardia, an increased heart rate that can occur as the body responds to decreased oxygen levels. These symptoms are direct manifestations of the body's response to the obstruction caused by a blood clot in the pulmonary arteries, which is the essence of a pulmonary embolism.