Estimation of the dry weight of a dialysis patient

Patent metadata

Field	Value
Publication number	US-2017239408-A1
Application number	US-201715591973-A
Country	US
Kind code	A1
Filing date	May 10, 2017
Priority date	Sep 19, 2011
Publication date	Aug 24, 2017
Grant date	—

Abstract

In an embodiment, the invention relates to methods, apparatus, computer programs and computer program products for estimating a dry weight of a dialysis patient comprising the steps of determining a first fluid status of the patient between treatment sessions in a first stage, determining a second fluid status of the patient during treatment sessions in a second stage and estimating the dry weight based on the second fluid status.

First claim

What is claimed is:

1 . Method for estimating a dry weight of a patient comprising the following steps:
i) determining a first fluid status of the patient between treatment sessions in a first stage (I); ii) determining a second fluid status of the patient during treatment sessions in a second stage (II); and iii) estimating the dry weight based on the second fluid status.

2 . Method according to claim 1 , wherein the patient is a dialysis patient and wherein the treatment sessions are-sessions of a dialysis treatment.

3 . Method according to claim 2 , wherein the first fluid status is determined by a pre-treatment session measurement.

4 . Method according to claim 3 , wherein the first fluid status is determined by a post-treatment session measurement.

5 . Method according to claim 4 , wherein the first fluid status is determined by at least one of:
a) a physical examination method, preferably the observation of pedal edema, the measurement of blood pressure and/or the determination of jugular venous pressure, b) an imaging method, preferably chest x-ray imaging and/or inferior vena caval diameter ultrasound imaging, c) biochemical markers, preferably ANP, BNP, nT-pro BNP and/or cGMP, d) a thermal dilution determination method, preferably an extravascular lung index determination, e) a bioimpedance measurement method, particularly a single-frequency bioimpedance measurement, preferably by a vector method, or a multi-frequency bioimpedance measurement, particularly with a BCM, preferably by whole body bioimpedance spectroscopy, more preferably by segmental bioimpedance spectroscopy (BIS) and most preferably by calf bioimpedance spectroscopy, f) the ratio between the total body water volume (TBW) and the extracellular water volume (ECV), and g) a blood volume measurement method, preferably by blood volume monitoring (BVM) and more preferably by determining the optical properties of blood in the intravascular compartment.

6 . Method according to claim 5 , wherein the second fluid status is determined by at least one of:
a) a) a blood volume measurement method, preferably by blood volume monitoring (BVM) and more preferably by determining the optical properties in the intravascular compartment, and b) b) segmental bioimpedance spectroscopy (BIS), preferably calf bioimpedance spectroscopy (cBIS). Method according to claim 6 , further comprising the step of estimating a normal fluid status based on the first fluid status.

8 . Method according to claim 7 , wherein the first stage (I) ends and/or the second stage (II) starts, if the determined first fluid status falls below 2.5 to 0.25 L, preferably below 1.5 to 0.5 L and most preferably below 1 L of post-treatment session fluid overload compared to an estimated normal fluid status of the patient.

9 . Method according to claim 8 , wherein the normal fluid status and/or weight (NFSW wBIS ) is estimated by a whole body model or by a calf normalized resistivity (CNR) method.

10 . Method according to claim 9 , wherein the first stage (I) ends and/or the second stage (II) starts, if a blood volume monitoring shows that the relative blood volume (RBV) decreases during a treatment session.

11 . Method according to claim 10 , wherein the relative blood volume (RBV) decreases by more than 5%, preferably by more than 10%, more preferably by more than 15% and most preferably by more than 20% during a treatment session.

12 . Method according to claim 11 , wherein the first stage (I) lasts approximately 1 to 6 months, preferably approximately 1 to 3 months and more preferably approximately 1 to 2 months.

13 . Method according to claim 12 , wherein the first fluid status is determined periodically, preferably every 1 to 6 weeks, more preferably every 2 to 4 weeks, even more preferably every 3 weeks, even more preferably every 10 th treatment session, even more preferably every 9 th treatment session, even more preferably every 8 th treatment session, even more preferably every 7 th treatment session, even more preferably every 6 th treatment session, even more preferably every 5 th treatment session, even more preferably every 4 th treatment session, even more preferably every 3 th treatment session, even more preferably every 2 th treatment session and most preferably every treatment session.

14 . Method according to claim 13 , wherein the first fluid status and/or the second fluid status is measured continuously or intermittently during a treatment session.

15 . Method according to claim 14 , wherein the second fluid status is determined during every treatment session.

16 . Method according to claim 15 , wherein the estimated dry weight of a patient is determined by the evolution of the second fluid status during treatment sessions.

17 . Method according to claim 16 , wherein the estimated dry weight of the patient is determined by analyzing the resistance curve and/or the normalized resistivity in the second stage (II).

18 . Method according to claim 17 , wherein the dry weight of the patient is reached if a flattening of the resistance curve of the patient recorded during a treatment session in the second stage is reached and/or the normalized resistivity of the patient is within a normal post-hemodialytic range for his/her comparison group.

19 . Method according to claim 18 , wherein the resistance is measured by calf bioimpedance spectroscopy and/or the normalized resistivity of the patient is the normalized calf resistivity.

20 . Method according to claim 19 , wherein the first fluid status, the second fluid status, the estimated normal fluid status, the estimated dry weight or any other data gained throughout a treatment session is transferred to a database, preferably via a data connection.

21 . Method according to claim 20 , wherein the database is operated at a central server.

22 . Method according to claim 21 , wherein the transferred data is processed such that statistics and/or conclusions for the treatment of the patient and/or a specific group of patients, in particular patients with comparable body parameters, may be derived.

23 . Method according to claim 22 , wherein the first fluid status, the second fluid status fluid status and/or any other data gained throughout the treatment session is used to determine the dosage of a medicament, preferably of EPO, antibiotics, and/or other parenterally-administered drugs.

Assignees

• Fresenius Medical Care Holdings Inc
• Fresenius Medical Care Deutschland Gmbh

Inventors

• Levin Nathan W
• Zhu Fansan
• Kotanko Peter
• Wabel Peter
• Tetta Ciro

Classifications

• A61B5/4839

  combined with drug delivery · CPC title

• A61B5/4878

  Evaluating oedema · CPC title

• A61B5/028

  by thermo-dilution · CPC title

• A61M1/1611 Primary

  Weight of the patient · CPC title

• A61B5/14546

  for measuring analytes not otherwise provided for, e.g. ions, cytochromes · CPC title