37-year-old man with Dyspnea

37-year-old man with known end-stage renal disease and chronic uraemic pericardial effusion presented with gradually worsening dyspnoea and orthopnoea, 4 days after a nephrectomy to control hypertension.

He had been having regular haemodialysis three-times per week for the preceding 9 years after rejection of a transplanted kidney.

On examination he was severely dyspnoeic at rest, and had a pulse rate of 102 beats per min, respiratory rate of 20 breaths per min, and blood pressure 110/70 mm Hg with 25 mm Hg paradoxical changes. Lung auscultation showed left basilar bronchial breath sounds.

What is the cause of this abnormal chest radiograph?