In a patient with suspected deep vein thrombosis (DVT), the primary concern is the risk of pulmonary embolism (PE), which occurs if a thrombus dislodges and travels to the lungs. Respiratory examination is crucial to detect signs of PE, such as crackles, which may indicate pulmonary infarction or edema. Early identification of respiratory abnormalities can prompt urgent intervention to prevent morbidity and mortality. Cardiac, abdominal, and neurological exams, while important in other contexts, do not directly assess complications related to DVT. Therefore, focusing on respiratory findings is vital for timely diagnosis and management.

Reference: Harrison’s Principles of Internal Medicine, J. Larry Jameson et al., 21st Edition.