Apparatus for extracorporeal blood treatment

A continuous renal replacement therapy (CRRT) apparatus comprising:

• a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;
• a blood circuit having a blood withdrawal line connected to an inlet of the primary chamber, and a blood return line connected to an outlet of the primary chamber, said blood circuit being configured for connection to a patient cardiovascular system;
• a blood pump to circulate blood in the blood circuit;
• a dialysis supply line connected to an inlet the secondary chamber;
• a dialysate line connected to an outlet of the secondary chamber;
• one or more lines to transfer a respective solution into blood;
• at least one fluid source of a solution for each of said one or more lines, wherein said solution comprises at least one buffer agent in the form of bicarbonate or bicarbonate precursor;
• a control unit configured to receive a patient prescription to set and deliver a CRRT blood treatment to the patient using the CRRT apparatus, the patient prescription including one or more of a blood flow rate in the blood circuit, a dialysis flow rate of dialysis fluid in the dialysis supply line, a patient fluid removal rate to be removed from the patient,
• wherein the control unit is further configured to:
• calculate a steady state acid-base balance parameter in the blood of the patient who has to undergo a CRRT blood treatment, wherein said steady state acid-base balance parameter is the net buffer load or the normalized net buffer load, and is calculated as a function of the concentration of said buffer agent in said fluid source and as a function of the estimated or calculated patient systemic steady state concentration of bicarbonate and bicarbonate precursors,
• calculate the steady state acid-base balance parameter in the blood of the patient as a function of one or more of:
• an estimation of an amount per unit of time of bicarbonate generated from metabolism of the bicarbonate precursor infused to the patient,
• a calculation of a lactate balance from the CRRT blood treatment to be delivered in terms of an amount per unit of time;
• a calculation of an acid infusion from citric acid contained in the fluid source in terms of an amount per unit of time;
• compare the steady state acid-base balance parameter in the blood of the patient with a threshold, and
• generate an alert when the steady state acid-base balance parameter exceeds the threshold,
• wherein the net buffer load during an extracorporeal blood treatment is the sum of bicarbonate generated into the patient from the metabolism of bicarbonate precursors, including citrate, and bicarbonate balance to the patient from the extracorporeal blood therapy.

A continuous renal replacement therapy (CRRT) apparatus comprising:

• a filtration unit having a primary chamber and a secondary chamber separated by a semi-permeable membrane;
• a blood circuit having a blood withdrawal line connected to an inlet of the primary chamber, and a blood return line connected to an outlet of the primary chamber, said blood circuit being configured for connection to a patient cardiovascular system;
• a blood pump to circulate blood in the blood circuit;
• a dialysis supply line connected to an inlet the secondary chamber;
• a dialysate line connected to an outlet of the secondary chamber;
• one or more lines to transfer a respective solution into blood;
• at least one fluid source of a solution for each of said one or more lines, wherein said solution comprises at least one buffer agent in the form of bicarbonate or bicarbonate precursor;
• a control unit configured to deliver a CRRT blood treatment to the patient using the CRRT apparatus, wherein, to deliver the CRRT blood treatment, the control unit is configured to:
• receive a patient prescription including one or more of a blood flow rate in the blood circuit, a dialysis flow rate of dialysis fluid in the dialysis supply line, a patient fluid removal rate to be removed from the patient for setting a CRRT blood treatment,
• calculate a steady state bicarbonate concentration in the blood of the patient who has to undergo the CRRT blood treatment, wherein said steady state bicarbonate concentration is calculated as a function of the concentration of said at least one buffer agent in said fluid source and as a function of one of the estimated or calculated net buffer load indicative of a steady state acid-base balance in the blood of the patient,
• calculate the steady state bicarbonate concentration in the blood of the patient, and bicarbonate losses in the dialysate, further based on:
• an estimation of an amount per unit of time of bicarbonate generated from metabolism of the bicarbonate precursor infused to the patient;
• a bicarbonate infusion from the CRRT blood treatment to be delivered in terms of an amount per unit of time;
• a predefined net buffer load chosen between 0 and 0.35 mmol/[h(kg)];
• an acid infusion from citric acid contained in the fluid source in terms of an amount per unit of time;
• compare the steady state bicarbonate concentration in the blood of the patient with a threshold, and
• generate an alert when the steady state bicarbonate concentration in the blood of the patient exceeds the threshold.