FCP2-501

A 47-year-old man with a history of alcohol induced liver disease is admitted to the gastroenterology ward. He has developed tense ascites again and a plan is made to site an ascitic drain. His renal function after 2 days is as follows:

Na+ 131 mmol/l
K+ 3.8 mmol/l
Urea 12.2 mmol/l
Creatinine 205 µmol/l

Which of the following pathophysiological changes is most likely to be responsible for the declining renal function?