Blood purification apparatus and method of estimating patient's state of nutrition on blood purification apparatus

A blood purification apparatus that includes

• a blood circuit including an arterial blood circuit and a venous blood circuit and that allows a patient's blood to extracorporeally circulate from a distal end of the arterial blood circuit to a distal end of the venous blood circuit;
• a blood purifier provided between the arterial blood circuit and the venous blood circuit and that purifies the patient's blood flowing through the blood circuit, the blood purifier having a blood flow route through which the patient's blood extracorporeally circulating through the blood circuit flows and a dialysate flow route through which dialysate flows, the blood flow route and the dialysate flow route being separated from each other by a blood purification membrane for purifying the patient's blood;
• an ultrafiltration unit that performs ultrafiltration by filtering out water from the patient's blood in the blood flow route through the blood purification membrane and draining the water through the dialysate flow route;
• and
• a detecting unit that detects a transmembrane pressure difference occurring on the blood purification membrane under a pressure difference between liquid in the blood flow route and liquid in the dialysate flow route,
• the blood purification apparatus comprising:
• a blood pump;
• a dialysate pump;
• a colloid-osmotic-pressure-acquiring unit that acquires a colloid osmotic pressure of the patient's blood in the blood flow route or a correlation value of colloid osmotic pressure with reference to the transmembrane pressure difference occurring when liquid that does not generate colloid osmotic pressure is supplied into the blood flow route with filtration by the ultrafiltration unit withheld and the transmembrane pressure difference occurring when the patient's blood is supplied into the blood flow route with the filtration by the ultrafiltration unit withheld;
• a plasma-total-protein-acquiring unit that acquires a plasma total protein or a correlation value of plasma total protein with reference to the colloid osmotic pressure or the correlation value of colloid osmotic pressure acquired by the colloid-osmotic-pressure-acquiring unit;
• and
• a control unit that executes:
• a first step in which the liquid that does not generate colloid osmotic pressure is supplied into the blood flow route with the filtration by the ultrafiltration unit withheld, and the transmembrane pressure difference is calculated by using the detecting unit;
• and
• a second step in which the patient's blood is supplied into the blood flow route with the filtration by the ultrafiltration unit withheld, and the transmembrane pressure difference is calculated by using the detecting unit,
• wherein the blood pump and a duplex pump are stopped to stop flow or liquid in the blood flow route and in the dialysate flow route;
• wherein the second step is performed while the blood pump and the duplex pump are stopped, on a condition that a predetermined time has lapsed since a start of a treatment in a treatment step;
• wherein the colloid-osmotic-pressure-acquiring unit acquires the colloid osmotic pressure or the correlation value of colloid osmotic pressure with reference to the transmembrane pressure difference calculated in the first step and the transmembrane pressure difference calculated in the second step;
• wherein the blood pump and the dialysate pump are stopped, on a condition that a predetermined time has lapsed since a start of a treatment in a treatment step and the patient's blood is supplied to the blood flow route by the ultrafiltration unit;
• wherein the plasma total protein or the correlation value of plasma total protein stored in a storage unit or transmitted to a server is linked to pieces of patient information;
• wherein the control unit is capable of sequentially executing a priming step in which a priming solution is supplied into the blood circuit and the treatment step in which blood purification treatment is performed with the blood purifier while the patient's blood is caused to extracorporeally circulate through the blood circuit;
• and
• wherein the liquid that does not generate colloid osmotic pressure and is supplied into the blood flow route in the first step is the priming solution that is used in the priming step;
• and the patient's blood that is supplied into the blood flow route in the second step is the patient's blood that is caused to extracorporeally circulate in the treatment step.