A 78-year-old female passenger has developed swelling of her left lower leg towards the end of a long-haul flight. She does not complain of any pain at rest. She has pitting edema of her left lower leg, but no color or temperature changes are observed. Calf pain is induced on dorsiflexion of her left foot. Because she suffers from shortness of breath, the possibility of pulmonary embolism should be considered, and transfer to an appropriate hospital is advised.

a. Acute kidney injury

b. Deep venous thrombosis

c. Femoral neck fracture

d. Heart failure

e. Peripheral arterial disease