Equipment for extracorporeal blood treatment

Abstract

A CRRT apparatus comprising a filtration unit (2), a blood circuit (17), a blood pump (21), a dialysate line (13) and one or more lines (8; 51; 57; 58; 63; 69; 67; 74) for transferring a respective solution into the blood; a fluid source for each of the one or more lines, wherein the solution comprises at least one buffer in the form of bicarbonate or a bicarbonate precursor. A control unit (12) is configured to receive a patient prescription and to determine a parameter (J) representing a steady-state acid-base balance in the blood of a patient who must undergo CRRT blood treatment. buffer_load / BW), wherein the parameter is determined based on the concentration of the buffer in the fluid source and based on an estimated or calculated systemic steady-state bicarbonate and / or bicarbonate precursor concentration of the patient.

Claims

1. A continuous renal replacement therapy (CRRT) device comprising: a filtration unit (2) having a main chamber (3) and a secondary chamber (4) separated by a semipermeable membrane (5); a blood circuit (17) having a blood withdrawal line (6) and a blood return line (7), wherein the blood withdrawal line (6) is connected to an inlet of the main chamber (3) and the blood return line (7) is connected to an outlet of the main chamber (3), and the blood circuit is configured to be connected to a patient's cardiovascular system; a blood pump (21) for circulating blood in the blood circuit (17); a dialysate line (13) connected to the outlet of the secondary chamber (4); one or more tubes (8; 51; 57; 58; 63; 69; 67; 74) for transferring the respective solution into the blood; at least one fluid source of a solution for each of the one or more conduits, wherein the solution comprises at least one buffer in the form of bicarbonate or a bicarbonate precursor; a control unit (12) configured to receive a patient prescription comprising parameters for setting a CRRT blood treatment, Characterized in that the control unit (12) is further configured to: determining a parameter indicative of steady-state acid-base balance in the blood of a patient who must undergo CRRT blood treatment, wherein the parameter is determined based on the concentration of the buffer in the fluid source and based on an estimated or calculated systemic steady-state bicarbonate and / or bicarbonate precursor concentration in the patient; or determining a parameter representing a steady-state bicarbonate concentration in the blood of a patient who must undergo CRRT blood treatment, wherein the parameter is determined based on the concentration of the buffer in the fluid source and based on an estimated or calculated net buffer load representing a steady-state acid-base balance in the patient's blood, Wherein, the control unit (12) is further based on the metabolism of citrate infused into the patient per unit time (J met_cit ) to determine a parameter representing the steady state bicarbonate concentration in the patient's blood.

2. The CRRT device according to claim 1, wherein: The one or more lines (8; 51; 58; 63; 74) for infusing the respective solution into the blood include an infusion line (63) for infusing a replacement solution comprising bicarbonate or a bicarbonate precursor into the blood, the device further comprising an infusion pump (65) and a replacement solution bag (64), the infusion pump (65) operating on the infusion line (63) to determine a replacement infusion rate (Q rep ), the substitution solution bag (64) is connected to the end of the infusion line (63) for infusing a solution comprising bicarbonate into the blood, wherein the infusion line (63) is connected to the return blood line (7) for post-infusion of the solution comprising bicarbonate.

3. The CRRT device according to claim 2, wherein: The infusion line (63) comprises a pre-infusion branch (67) and a post-infusion branch (69) to allow infusion upstream and downstream of the filtration unit (2).

4. The CRRT device according to claim 1, wherein: The one or more lines (8; 51; 58; 63; 74) for infusing the respective solutions into the blood include an anticoagulant line (51) for infusing the anticoagulant solution directly into the blood circuit (17), the device also comprising an anticoagulant pump (54) and an anticoagulant solution bag (10), the anticoagulant pump (54) operating on the anticoagulant line (51) to determine the anticoagulant infusion rate (Q cit ), the anticoagulant solution bag (10) is connected to the end of the anticoagulant line (51) for infusing a solution comprising citrate or citrate and citric acid into the blood circuit (17), wherein the anticoagulant line (51) is connected to the blood drawing line (6).

5. The CRRT device according to claim 1, wherein: The parameter (J) representing the steady-state acid-base balance in the blood of patients undergoing CRRT treatment buffer_load / BW) is a parametric function of the expected net buffer load (NBL) in the patient at steady state, where the net buffer load is normalized to the patient's body weight (BW), and The control unit (12) determines a parameter (J) representing a steady-state acid-base balance in the patient's blood based on one or more of the following: buffer_load / BW): An estimate of the amount of bicarbonate produced per unit time by the metabolism of a bicarbonate precursor infused into the patient; Bicarbonate balance from CRRT blood treatment to be delivered expressed as amount per unit time (J HCO3_bal ); Lactate balance from CRRT blood treatment to be delivered expressed as amount per unit time (J lact_bal ); Acid infusion expressed as amount per unit time from the citric acid contained in the fluid source (J H+ ).

6. The CRRT device according to claim 5, wherein: The control unit (12) determines a parameter (J) representing the steady-state acid-base balance in the patient's blood as follows buffer_load / BW): Alternatively, when lactate balance is also taken into account, the control unit (12) determines the parameter (J) representing the steady-state acid-base balance in the patient's blood as follows buffer_load / BW):

7. The CRRT device according to claim 5, wherein: When relevant, the net buffer load during extracorporeal blood treatment is the bicarbonate produced by the metabolism of bicarbonate precursors, the bicarbonate balance (J) from the extracorporeal blood treatment HCO3_bal ) and acid infusion.

8. The CRRT device according to claim 7, wherein: The bicarbonate precursor comprises at least citrate and / or lactate which is infused into the patient. met_cit ; J met_lact ).

9. The CRRT device according to claim 7 or 8, wherein: Bicarbonate balance from extracorporeal blood treatment (J HCO3_bal ) is the patient's net bicarbonate loss or gain.

10. The CRRT device according to claim 7 or 8, wherein: The acid infusion includes a citric acid content.

11. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) is configured to determine a parameter (Cp) representing a steady-state bicarbonate concentration in the patient's blood. HCO3_pat ), imposing a constant value for the normalized net buffer load (NBL) of patients in steady state.

12. The CRRT device according to claim 11, wherein: The constant value is 0.1 mmol / h / kg.

13. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) determines a parameter (Cp) representing a steady-state bicarbonate concentration in the patient's blood based on one or more of the following: HCO3_pat ), wherein the parameter (Cp HCO3_pat ) including bicarbonate losses in the dialysate (J HCO3_dial ): An estimate of the amount of bicarbonate produced per unit time by the metabolism of a bicarbonate precursor infused into the patient; Bicarbonate infusion from CRRT blood treatment to be delivered expressed as amount per unit time (J HCO3_inf ); Lactate balance from CRRT blood treatment to be delivered expressed as amount per unit time (J lact_bal ); Predefined net buffer load Wherein, the net buffer load Selected from 0 to 0.35 mmol / h / kg; Acid infusion expressed as amount per unit time from the citric acid contained in the fluid source (J H+ ).

14. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) estimates the metabolism of precursors in the form of bicarbonate (J met_cit ,J lact ), bicarbonate infusion (J HCO3_bal ), predefined net buffer load and acid infusion (J H+ ) to determine the parameter representing the patient's steady-state bicarbonate concentration in the blood (Cp HCO3_pat ), in case of patient buffer loss, the acid infusion (J H+ ) is a negative term.

15. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) is based on acid infusion (J H+ ) to determine the parameter representing the steady-state acid-base balance in the patient's blood (J buffer_load / BW), wherein the acid infusion (J H+ ) is the acid infusion from the citric acid contained in the fluid source expressed in amount per unit time, wherein the acid infusion (J H+ ) is the acid concentration (C citric_pbp ) and the acid infusion rate (Q cit ) function.

16. The CRRT device according to claim 15, wherein: The acid infusion (J H+ ) is equal to 3 times the concentration of citric acid (C citric_pbp ) multiplied by the infusion rate of citrate (Q cit ).

17. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) calculates the amount of bicarbonate produced by the metabolism of citrate per unit time, wherein the control unit calculates the amount of bicarbonate produced by the metabolism of citrate per unit time according to the patient's citrate metabolic clearance rate (K cit_met ) Calculate the citrate load (J cit_load ), where metabolic clearance is based on patient body weight (BW).

18. The CRRT device according to claim 17, wherein: The metabolic clearance was determined as shown in the following formula:

19. The CRRT device according to claim 17, wherein: The control unit is based on the citrate clearance rate (K cit ) Calculate the citrate load (J cit_load ), and wherein the control unit (12) determines the citrate clearance (K) based on one or more flow rates cit ), wherein the one or more flow rates include a dialysis flow rate (Q d ), plasma water flow rate (Qpw inlet ), ultrafiltration rate (Q fil ), or the control unit (12) determines the citrate clearance (K) according to the filter unit (2) intended for CRRT treatment. cit ), the filter unit (2) intended for CRRT treatment comprises a sieving coefficient (SC cit ) and / or the filter unit surface area and diffusion mass transfer resistance (K0A cit The citrate clearance (K cit ).

20. The CRRT device according to claim 13, wherein: The control unit (12) calculates the amount of bicarbonate produced by the metabolism of citrate per unit time, wherein the control unit calculates the amount of bicarbonate produced by the metabolism of citrate according to the citrate dosage (D cit ) and blood flow (Q b ) Calculate the citrate load (J cit_load ), that is, according to D cit Q b Calculate the citrate load (J cit_load ),or The control unit controls the flow rate (Q) of the citrate in the anticoagulant line (51) according to the flow rate of the citrate in the anticoagulant line (51). cit ) and total citrate concentration (C cit_pbp ) to calculate the citrate load (J cit_load ), that is, according to Q cit · Calculate the citrate load (J cit_load ).

21. The CRRT device according to claim 13, wherein: The control unit (12) calculates the amount of bicarbonate produced by the metabolism of citrate per unit time, wherein the control unit calculates the citrate load (J) according to the following formula: cit_load ): Alternatively, if the patient's systemic citrate concentration is assumed to be zero, the citrate load (J) is calculated according to the following formula: cit_load ):

22. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) is based on the bicarbonate balance (J) from the CRRT blood treatment to be delivered, expressed in terms of amount per unit time. HCO3_bal ) to determine the parameter representing the steady-state acid-base balance in the patient's blood (J buffer_load / BW), wherein the bicarbonate balance (J HCO3_bal ) is the infusion rate (J) of the dialysis fluid and / or replacement fluid HCO3_inf ) and bicarbonate removed into the dialysate (J HCO3_dial ) between .

23. The CRRT device according to claim 22, wherein: The control unit (12) calculates the bicarbonate balance (J) according to one or more of the following: HCO3_bal ): Replacement flow rate (Q rep ) and the bicarbonate concentration in the replacement solution (C HCO3_rep ), that is, according to Q rep ·C HCO3_rep Calculate the bicarbonate balance (J HCO3_bal ); Bicarbonate plasma water concentration at the filter inlet (Cpw HCO3_inlet ); Bicarbonate plasma water concentration at the filter inlet (Cpw HCO3_inlet ) and the bicarbonate concentration in the dialysis fluid (C HCO3_d ) Ultrafiltration rate (Q fil ) and the bicarbonate concentration in the dialysis fluid (C HCO3_d ); Bicarbonate clearance (K HCO3 ), wherein the control unit (12) determines the bicarbonate clearance rate (K) based on one or more flow rates HCO3 ), wherein the one or more flow rates include a dialysis flow rate (Q d ), blood water flow rate (Qbw inlet ), ultrafiltration rate (Q fil ), or the control unit (12) calculates the bicarbonate clearance (K) based on the filtration unit (2) intended for CRRT treatment. HCO3 ), the filtration unit (2) intended for CRRT treatment comprises a sieving coefficient (SC HCO3 ) and / or bicarbonate filter unit surface area and diffusion mass transfer resistance (K0A HCO3 ) ratio.

24. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) is configured to compare a parameter representing a steady-state acid-base balance in the patient's blood with a threshold value, and in a case where the threshold value is an upper threshold value, when the parameter is higher than the upper threshold value, the control unit (12) generates an alarm, and in a case where the threshold value is a lower threshold value, when the parameter is lower than the lower threshold value, the control unit (12) generates an alarm, wherein, in a case where the parameter exceeds the threshold value, the control unit (12) is configured to issue an alarm and maintain the input patient prescription, or to issue an alarm and reject the input patient prescription, Wherein, in the case that the input prescription is rejected, the control unit (12) is further configured to: reinstate a previously valid patient prescription; or One or more parameters of the patient prescription, the one or more parameters being blood flow rate and / or citrate dosage, are automatically converted into suggested values ​​defining a new effective patient prescription.

25. The CRRT device according to claim 24, wherein: Assuming that the target bicarbonate concentration set for a steady-state patient is comprised between 24 mmol / l and 26 mmol / l, said threshold comprises an upper threshold comprised between 0.25 mmol / h / kg and 0.5 mmol / h / kg, wherein: a first upper threshold value (nNBL1) comprised between 0.25 mmol / h / kg and 0.35 mmol / h / kg; and / or The second upper threshold value (nNBL2) is comprised between 0.35 mmol / h / kg and 0.5 mmol / h / kg, And, wherein the threshold value comprises a lower threshold value comprised between 0 and -0.2 mmol / h / kg, the control unit (12) is further configured to issue an alarm and / or block the input of the prescription if the parameter is below the lower threshold value.

26. The CRRT apparatus according to any one of claims 1 to 8, wherein: The device comprises: a dialysis fluid source for providing fluid to the dialysis supply circuit, the dialysis fluid being substantially free of buffer; a replacement solution bag (64) containing a replacement solution having a buffer, wherein the buffer concentration in the replacement solution is comprised between 0 and 1000 mmol / l; if the buffer concentration is between 100 mmol / l and 200 mmol / l, in combination with an unbuffered dialysate and / or an unbuffered other replacement fluid; or If the buffer concentration is between 50 mmol / l and 100 mmol / l, in combination with a low-buffer dialysate having a buffer content of less than 25 mmol / l and / or a low-buffer other replacement fluid having a buffer content of less than 25 mmol / l, The one or more lines (8; 51; 58; 63; 74) for infusing the respective solution into the blood include an infusion line (63) connected to the substitution solution bag (64) for infusing the replacement solution into the blood, The infusion line (63) is a post-infusion line, which infuses the buffer into the blood circuit (17) downstream of the filtration unit (2), and the buffer includes bicarbonate.

27. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) is configured to receive patient prescription parameters and to determine a parameter representative of a steady-state acid-base balance in the patient's blood based on one or more of the prescription parameters or based on a parameter derived directly from the prescription parameters, wherein the control unit (12) receives a patient prescription comprising one or more of the following: a blood flow rate (Q) in the blood circuit (17); b ), the dialysis flow rate (Q d ), the patient fluid removal rate (Q wl ), and the dialysate flow rate (Q dial ), or the control unit (12) is configured to receive patient prescription parameters, the patient prescription parameters including the blood flow rate (Q b ), the dialysis flow rate (Q d ) and the patient fluid removal rate (Q wl ), or, the control unit (12) is configured to receive patient prescription parameters, the patient prescription parameters comprising: Fluid flow rate of the displacement fluid (Q rep ), i.e. the total flow rate of the replacement fluid pre-infused and post-infused into the filtration unit (2), and the ratio of pre-infusion to post-infusion of the replacement fluid (PRE%); or The post-infusion flow rate of the replacement fluid (Q post ) and / or the pre-infusion flow rate of the replacement fluid (Q pre ).

28. The CRRT apparatus according to any one of claims 1 to 8, wherein: The control unit (12) determines a parameter representing the steady-state acid-base balance in the patient's blood according to any one of the following definitions: or NBL=J buffer_load =J met_cit +J HCO3_bal Alternatively, when acid infusion is taken into account, the control unit (12) determines the parameter representing the steady state acid-base balance in the patient's blood as follows: or NBL=J buffer_load =J met_cit +J HCO3_bal -J H+ Alternatively, when lactate balance is also taken into account, the control unit (12) determines the parameter representing the steady-state acid-base balance in the patient's blood as follows: or nNBL=J buffer_load =J met_cit +J HCO3_bal +J met_lact -J H+ , Where, NBL represents the net buffer load, nNBL represents the normalized net buffer load, and J buffer_load represents the net buffer load, J met_cit Indicates the metabolism of citrate, J HCO3_bal represents bicarbonate balance, J H+ Indicates acid infusion, J met_lact represents lactate metabolism, and BW represents patient weight.

29. A continuous renal replacement therapy (CRRT) device comprising: a filtration unit (2) having a main chamber (3) and a secondary chamber (4) separated by a semipermeable membrane (5); a blood circuit (17) having a blood withdrawal line (6) and a blood return line (7), wherein the blood withdrawal line (6) is connected to an inlet of the main chamber (3) and the blood return line (7) is connected to an outlet of the main chamber (3), and the blood circuit is configured to be connected to a patient's cardiovascular system; a blood pump (21) for circulating blood in the blood circuit (17); a dialysate line (13), connected to the outlet of the secondary chamber (4); one or more tubes (8; 51; 57; 58; 63; 69; 67; 74) for transferring the respective solution into the blood; at least one fluid source of a solution for each of the one or more conduits, wherein the solution comprises at least one buffer in the form of bicarbonate or a bicarbonate precursor; a control unit (12) configured to receive a patient prescription comprising parameters for setting a CRRT blood treatment, Characterized in that the control unit (12) is further configured to: determining a parameter indicative of steady-state acid-base balance in the blood of a patient who must undergo CRRT blood treatment, wherein the parameter is a net buffer load or a normalized net buffer load and is determined based on the concentration of the buffer in the fluid source and based on an estimated or calculated systemic steady-state bicarbonate and / or bicarbonate precursor concentration in the patient, wherein the parameter (J) representing the steady-state acid-base balance in the blood of patients undergoing CRRT treatment buffer_load / BW) is a parametric function of the expected net buffer load (NBL) in the patient at steady state, and The control unit (12) determines a parameter (J) representing a steady-state acid-base balance in the patient's blood based on at least three of the following: buffer_load / BW): An estimate of the amount of bicarbonate produced per unit time by the metabolism of a bicarbonate precursor infused into the patient; Bicarbonate balance from CRRT blood treatment to be delivered expressed as amount per unit time (J HCO3_bal ); Lactate balance from CRRT blood treatment to be delivered expressed as amount per unit time (J lact_bal ); Acid infusion expressed as amount per unit time from the citric acid contained in the fluid source (J H+ ); The net buffer load during extracorporeal blood treatment includes bicarbonate generated into the patient by the metabolism of bicarbonate precursors including citrate, balanced by bicarbonate from the patient undergoing extracorporeal blood treatment (J HCO3_bal ) and.

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