RU2188671C1 - Method for determining optimum sorbent type and sorption time required for cleaning organism in carrying out plasmosorption - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves determining initial marker substance concentration C₀ in patient blood plasma. The plasma is distributed over 4xN test tubes, where N is the number of sorbents under test. Equal quantities of each sorbent are added to plasma in 4 test tubes and incubation is carried out for 5,10, 15 and 20 min, respectively. Then, marker substance C_i,k concentration in plasma is to be determined, where k is the number of sorbent under test and i is the test tube number in each set. Concentration difference is calculated from formula S_1,k = C_1,k-C₀, S_i,k = C_i,k-C_i-1,k. Minimum value of index i varying from 1 to 3 is to be found so that one of relationships S_i+1,k<0, |S_i,k|/10>|S_i+1,k|, is to be satisfied, The value is denoted as m(k) and C_m(k),k. values are to be compared. The sorbent which C_m(k),k is found to reach minimum value is considered to be optimum for sorption. The sorption time is thought to be equal to 5 min multiplied by m(k). EFFECT: enhanced effectiveness of treatment. 2 tbl

Description

 The invention relates to clinical medicine, in particular to efferent therapy, and can be used to clean plasma of endogenous and exogenous toxins, as well as substances in excess accumulated in the body, using plasma sorption.

 There is a method of determining indications for conducting efferent therapy by biochemical research [1], when blood is taken from a patient, serum is obtained from it, the effective concentration of albumin, the half-life and clearance of antipyrine are determined and, based on the measured values, they decide on hemosorption. The specified method is analogous to that proposed in terms of biochemical analysis, however, this method only determines the possibility of carrying out efferent therapy, but not the optimal type of sorbent for its implementation.

 A known method of conducting efferent therapy [2] is when a patient takes 700-800 ml of blood from an artery within 30-40 minutes, which is replaced by donor blood, then the blood is incubated for 10-15 minutes with a sorbent. In this case, the sorption of soluble blood components occurs, and thus it is cleaned of toxins and substances in excess accumulated in the body. After incubation with the sorbent, blood is returned to the patient. The cleaning efficiency of the body is evaluated by the degree of decrease in the concentration of the substance that was required to be removed from the body. The specified method is analogous to that proposed in part of the procedure for incubating biological fluid with a sorbent and we have chosen as a prototype.

 The disadvantage of the prototype is that the type of sorbent is chosen arbitrarily, without taking into account its properties, while the dynamics of the sorption process and the sorption capacity of various sorbents are not the same with respect to various substances.

 The present invention is directed to increasing the efficiency of plasma purification by determining the optimal type of sorbent.

 The goal is achieved as follows.

 The test sorbents are numbered from 1 to N, where N is the number of tested sorbents. Then 4 • N tubes are numbered, two indices are assigned to each tube (i, k), where index k is the sorbent number, varies from 1 to N, and index i is the number of the tube in the series, varies from 1 to 4. Thus, N series of tubes, 4 tubes in each series. Each of the tested sorbents is added in equal parts to the corresponding series of tubes. The amount of added sorbent in all series is the same.

 Then, in accordance with the nature of the disease, a substance is selected that needs to be excreted from the body, called hereinafter marker (for example, uric acid with gout).

 Then, the hematocrit and body weight are measured in a patient by standard methods.

In accordance with [3], the bcc is calculated by the formula
BCC = MT • 75 [ml], (1)
where MT is body weight, 75 is the average blood volume per 1 kg of MT.

OCP is calculated by the formula
CPL = BCC • (l00-Ht) [ml], (2)
where Ht is the hematocrit level (%).

 Then, blood is taken from a peripheral vein in a patient in a sterile vial with heparin added at the rate of 5 PIECES per 1 ml in the volume necessary for subsequent biochemical analyzes. The vial of blood is centrifuged and plasma is taken into chemically clean dishes. Cytomass is resuspended in sterile NaCl solution of isotonic concentration and reinfused to the patient.

From the plasma obtained in this way, the amount necessary to measure the initial concentration of the marker substance (C ₀ ) is selected, the decrease of which is expected during plasma sorption.

 The remaining plasma is poured in equal parts into 4 • N tubes. The plasma volumes and each of the sorbents are selected so that the ratio of plasma and sorbent is the same as during subsequent plasma sorption, for example, according to the method [2]. Then incubate the plasma with the sorbent with gentle stirring so that the granules of the sorbent are not destroyed.

 Plasma is taken from the tubes to determine the concentration of marker substance remaining in the plasma: from tubes with indices 1, k - after 5 minutes; 2, k - after 10 minutes; 3, k - after 15 minutes; 4, k - after 20 min, where k is the index of a series of tubes from 1 to N.

The measured concentrations are denoted by C _{i, k} , where i, k are the indices of the corresponding tubes.

Then, the concentration difference S _{i is} calculated (index i varies from two to four, k - from 1 to N) using the formulas
S _{1, k} = C _{1, k} -C ₀ , (3)
S _{i, k} = C _{i, k} -C _{i-1, k} . (4)
Then, for each value of k, they search for the smallest value of index i in the range from 1 to 3, for which at least one of the relations (5) or (6) is satisfied:
S _{i + 1, k} <0, (5)
| S _{i, k} | / 10> | S _{i + 1, k} | (6)
and denote it by m (k). If such a value of the index i does not exist, then for this series we assume m (k) = 4.

Then, for all k, compare C _{m (k) .k} and select the sorbent optimal for sorption, for which the value of C _{m (k) .k} is minimal, and the optimal sorption time for the kth sorbent is assumed to be five minutes times m ( k).

 EXAMPLE.

 Before plasma sorption in a patient with gout, the optimal type of sorbent was determined by the proposed method. The marker substance was selected uric acid (MK). Sorbents of three grades were investigated: SKT-6A, FAS and YA08 / 16AWLC.

 The patient's weight was 86 kg, bcc = 6450 ml, Ht = 42%, OCP = 3741 ml.

100.0 ml of blood was taken from the patient; after centrifugation, 58.0 ml of plasma was obtained, of which 4.0 ml of plasma was taken to determine the initial concentration (C ₀ ). Then, the remaining plasma (4.5 ml each) was poured into 12 tubes.

 Then, 0.36 ml of a sorbent of the corresponding grade was added to the test tubes of each series (SKT-6A - to test tubes of series 1; FAS - to test tubes of series 2; YA08 / 16AWLC - to test tubes of series 3). In the first tubes of each series, incubation was carried out for 5 minutes, in the second - 10 minutes, in the third - 15 minutes, in the fourth - 20 minutes.

 During incubation, the plasma in the tubes was stirred by slowly shaking. After incubation in each sample, the concentration of marker substance (uric acid) was measured in a standard way.

 The data obtained are shown in table 1.

Next, S _{i, k were} calculated by formulas (3) and (4). The results are presented in table 2.

 For the first series (index k is 1, SKT-6A sorbent), relation (6) is not satisfied for any values of index i, and relation (5) is satisfied for i equal to 3, we obtain m (1) is 3. For the second series (index k is 2, the FAS brand sorbent) relation (6) is not satisfied for any values of index i, and relation (5) holds for i equal to 3, we obtain m (2) is 3. For the third series (index k equal to 3, sorbent of the brand YA08 / 16AWLC) relation (6) holds for index i equal to 2, and relation (5) holds for i equal to 3, we get m (3) equal to 2.

Now we compare the concentration values With _{m (k) .k} , i.e. it is necessary to find the minimum value from C _3.1 (17 μmol / L), C _3.2 (43 μmol / L), C _2.3 (39 μmol / L). The minimum of these is C _3.1 (17 μmol / L). Therefore, the optimal type of sorbent for sorption of uric acid in the blood plasma of this patient is coal grade SKT-6A, and the optimal sorption time is 15 minutes.

 Thus, the above example illustrates the application of the proposed method for determining the optimal type of sorbent for removing marker substances (uric acid) from the body of a given patient.

LITERATURE
1. Kuznetsova E.E. et al. Method for determining indications for efferent therapy. // Application for a patent of the Russian Federation 96120708 A dated 10/14/1996, MKP 6 G 01 N 33/48.

 2. Lopukhin Yu.M., Molodenkov M.N. Hemosorption. // M., Medicine, 1978, p. 73.

 3. Propaedeutics of internal diseases. // Ed. V.Kh. Vasilenko and A.L. Grebeneva. - M .: Medicine, - 1982. - S. 253.

Claims (1)

The method of determining the optimal type of sorbent and sorption time when cleaning the body of the marker substance using plasma sorption, which consists in taking the patient’s blood, separating the blood cells from the plasma, returning the cell mass to the patient’s body, measuring the initial concentration of C ₀ marker substance in the obtained plasma and incubating plasma with a sorbent, characterized in that the resulting plasma is poured into 4 × N tubes, where N is the number of tested sorbents, equal portions of each sorbent are poured into four tubes, numbered from 1 to 4, incubate the plasma with the sorbent with gentle stirring in a test tube for 1 - 5 min, 2 - 10 min, 3 - 15 min, 4 - 20 min, after which the concentration of marker substance C _{i, k} in the plasma is determined, where k - the number of the tested sorbent, ai - the number of tubes in each series, calculate the values of the differences in concentrations according to the formula
S _{i, k} = C _{1, k} -C ₀ ,
S _{i, k} = C _{i, k} -C _{i-1, k} ,
where i is the index, varying from 2 to 4, and k is from 1 to N,
for each value of k, they search for the smallest value of index i in the range from 1 to 3, for which at least one of the following relations holds:
S _{i + 1, k} <0,
| S _{i, k} | / 10> | S _{i + 1, k} |,
and denote it by m (k), if such an index i does not exist, then for this series we assume m (k) = 4, after which C _{m (k) is} compared for all k _, and the sorbent is considered optimal for sorption for which the value of C _{m (k), k} will be minimal, and the optimum sorption time for the k-th sorbent is assumed to be 5 min times m (k).

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