How to avoid shock Abdominal dialysis requires a large shift of fluid (two to three liters) into the belly with another shift from the blood vessels into the abdominal cavity. The fluid then shifts back to the outside with the added liquid from the blood. In view of this, there is the possibility of a sudden loss of blood pressure if the exchange takes place too quickly. The inflow and outflow tubes have a thumbwheel regulator on them by which the nurse can slow down the flow. The blood pressure also must be taken once before, during, and after the procedure. As the patient or family member, you will want to keep an eye on this to make sure it is being done properly.