11th January 2024

A 78-year-old lady with known congestive cardiac failure presents to the emergency department with worsening shortness of breath and cough.

A 78-year-old lady with known congestive cardiac failure presents to the emergency department with worsening shortness of breath and cough. A chest x-ray is completed, which shows blunting of the right costophrenic angle and a large pleural effusion on the left. A diagnostic aspiration and blood tests are completed. 

Investigations: 

Serum WCC 14.9 10*9/L    (4.0-11.0) 

Serum CRP 99.0                 (<10) 

Serum protein 59g/L         (60-78)

Serum LDH 125units/L    (60-160)

Pleural fluid protein 30g/L 

Pleural fluid LDH 88 units/L 

Pleural fluid pH 7.51 

Given the above results, what is the most likely pathophysiological mechanism of her pleural effusion? 

Select the SINGLE most appropriate option from the list below. Select ONE option only.