After a client undergoes a paracentesis where 5 liters are removed, the priority assessment would be to monitor the client's vital signs and fluid status closely. The client may experience changes in blood pressure, heart rate, and urine output due to the rapid removal of fluid. The nurse should also monitor for signs and symptoms of hypovolemia, such as dizziness, weakness, thirst, and decreased urine output. The client's weight should also be monitored to assess for fluid shifts. Additionally, the nurse should assess the insertion site for signs of infection or bleeding.