A 60-year-old woman who underwent hip replacement 10 days ago has left calf pain and swelling. She has no haemoptysis, no malignancy, is not bedridden, and calf swelling is 4 cm greater than the right with tenderness along the deep veins. Using the Wells score for suspected lower limb DVT, her probability category and appropriate first investigation are:

• A Low probability, D-dimer alone
• B Moderate probability, contrast venography
• C Low probability, impedance plethysmography
• D High probability, proceed directly to compression ultrasonography ✓

Explanation

She scores 2 points each for recent immobilisation (plaster, paresis, or recent lower limb surgery within 12 weeks) and calf swelling over 3 cm compared with the other leg, plus 1 point for localised tenderness, giving 5 points, a high probability (score of 2 or more). In high probability patients, C-dimer should be skipped and compression ultrasonography performed directly. Contrast venography is now reserved for inconclusive ultrasound.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.