History A 73-year-old man has presented to the emergency department with severe pain in his knee. The pain started two days ago and he is now unable to walk. He has a history of hypertension and heart failure for which he has been taking bisoprolol, lisinopril, aspirin, simvastatin and bendroflumethiazide. Recently, he started taking furosemide because of increasing ankle oedema. Examination The left knee is swollen with evidence of an effusion, and it is erythematous, tender on touching and painful on any movement. No other joint is affected.
There is no skin rash. Joint aspiration is carried out on the knee. Observations Temperature- 37.9°C Blood pressure- 142/86 mmHg Heart rate- 76/minRespiratory rate- 18/min Knee X-ray reveals no bony abnormalities. Investigations Synovial fluid: White cells- 18000/mL (75% neutrophils), no pathogen present, negatively birefringent crystals seen. …
