RU2747159C1 - Method for assessing clinically significant chronic kidney disease - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to nephrology, functional diagnostics, and can be used to assess chronic kidney disease stage 3-5. For this, an ultrasound examination of the skin with a high-frequency sensor is carried out on the palmar surface of the distal phalanx of the middle finger of the left hand. An ultrasound image of a skin area with visualization of the dermis and subcutaneous fat is displayed on the monitor screen of an ultrasound apparatus, followed by an assessment of the percentage of the number of echo-positive and echo-negative pixels in the ultrasound image area - indicator P1. Then, at the beginning of the venous phase of the contrast-enhanced ultrasound examination of the kidneys, timing is started, 15 seconds are counted, and a high-frequency ultrasound examination of the skin is performed 7 times every 30 seconds with an assessment of the percentage ratio of the number of echo-positive and echo-negative pixels in the ultrasound image of the skin area - the group of indicators P2-P8. After that, the difference between the arithmetic mean of P2-P8 and P1 is calculated. If this difference is less than or equal to 12%, a conclusion is made about the presence of chronic kidney disease of 3-5 stages. If this difference is more than 12%, but less than 19%, they conclude that the patient does not have chronic kidney disease of 3-5 stages.

EFFECT: method provides for the determination of chronic kidney disease stage 3-5 by assessing the presence and severity of peripheral microcirculation disorders against the background of chronic kidney disease with the simultaneous use of contrast-enhanced ultrasound of the kidneys and high-frequency ultrasound of the skin, which also makes it possible to reduce the level of invasiveness, reduce the time for assessing the state of the peripheral microcirculation and to be able to conduct a semi-quantitative assessment of pathological changes at the screening stage.

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Description

The invention relates to medicine and can be used in radiation diagnostics and the clinic of internal diseases.

Known methods for assessing chronic kidney disease: biochemical blood test, determination of the level of glomerular filtration rate, dynamic nephrosyentigraphy (Clinical guidelines: chronic kidney disease (CKD) / Association of Nephrologists, 2019). These methods make it possible to detect chronic kidney disease in the later stages (stages 3-5, end-stage renal failure), when the use of symptomatic therapy is indicated. Diagnosis of chronic kidney disease in the early stages (stages 1-2) is limited to the above methods. It is in the early stages that effective nephroprotective therapy is possible. Diagnosis of chronic kidney disease in the early stages and dynamic monitoring of its development is carried out by conducting multiple general urine tests and biochemical blood tests, which are an invasive procedure (Fundamental and Clinical

physiology / A.G. Kamkina, A.A. Kamensky - M .: "Academy", 2014; Pathological physiology / V.A. Frolov - M .: 1997).

The technical result of the proposed invention is the determination of chronic kidney disease stage 3-5 by assessing the presence and severity of peripheral microcirculation disorders against the background of chronic kidney disease with the simultaneous use of contrast-enhanced ultrasound of the kidneys and high-frequency ultrasound of the skin. (Contrast sonography / Hans - Peter Weskott - 1st edition - Bremen: UIN - MED, 2014; Ultrasound diagnostic devices: modes, methods and technologies - Moscow: OOO PKF "IzoMed", 2011).

An essential feature of the vascular bed of the skin, in addition to its participation in thermoregulation, is the presence of many arteriovenous anastomoses, which make it possible to discharge blood from the arterial section to the venous one bypassing the capillary bed, which makes it possible to assess with high accuracy the architectonics of the vessels using a high-frequency ultrasonic sensor (48 MHz). Due to the discrete principle of the structure of the microvasculature of the skin, each area contains its own microvascular module. This principle is convenient for the segmental assessment of the studied area of the skin. In the area of the skin of the fingertips, there is the greatest number of anastomoses. Arteriovenous anastomoses, especially their arterial and intermediate segments, differ from the surrounding vessels by the presence of a denser innervation of the adrenergic nature, provide an operative redistribution of blood flow between superficial and deeply located vessels of the skin (Molvneux AS. Neural control of arteriovenous anastomoses. Microvasc Res. 1980; 19 (2 ): 256-259.)

The physiological rationale for the proposed method is that it is impossible to determine the microvasculature in a conventional B-mode ultrasound examination, this requires special

instrumental methods: laser Doppler, microscopy of capillaries, high-frequency Doppler (Evaluation of the blood microcirculation using laser Doppler flowmetry / IV Barkhatov - Clinical Medicine, 2013). All these techniques have a drawback in terms of assessing the severity of microcirculation disorders in chronic kidney disease: it is impossible to assess the general background of violations of all small-diameter vessels throughout the depth of the skin and subcutaneous tissue. This disadvantage is absent in high-frequency ultrasound examination of the skin (sensor frequency 48 MHz) with an estimate of the number of pixels in acoustic lines in the ultrasound image (in percentage terms of the ratio of pixels of different tonality).

In pathological conditions, such as chronic kidney disease, both the intensity of blood flow through the vessels of the skin and its distribution between capillaries and arteriovenous anastomoses change, which is well visualized in a combined study using contrast - enhanced ultrasound of the kidneys and high-frequency ultrasound of the skin (transducer frequency 48 MHz). (Clinical dermatology / A.N. Rodionov, D.V. Zaslavsky, A.A. Sydikov, 2019).

The essence of the method lies in the determination of chronic kidney disease stages 3-5 by assessing the presence and severity of peripheral microcirculation disorders using contrast-enhanced ultrasound of the kidneys and high-frequency ultrasound of the skin before and during intravenous contrast enhancement with the determination of the difference between the percentage ratio of the pixels of the acoustic lines ...

The method is carried out as follows: when conducting ultrasound examination of the skin with a high-frequency sensor 1 (Fig. 1) on the palmar surface of the distal phalanx of the middle finger of the left hand 2 (Fig. 1)

1) an ultrasound image of a skin area 5 (Fig. 1) with visualization of the dermis 3 (Fig. 1) and subcutaneous fat 4 (Fig. 1) is displayed on the monitor screen of an ultrasound apparatus, followed by an assessment of the percentage of the number of echo-positive and echo-negative pixels on ultrasound image in the skin area 5 (Fig. 1) (index P1); then, at the beginning of the venous phase of the contrast-enhanced ultrasound of the kidneys, according to the standard program, timing is started, 15 seconds are counted, and a high-frequency ultrasound examination of the skin is performed 7 times every 30 seconds with an assessment of the percentage ratio of the number of echo-positive and echo-negative pixels in the ultrasound image in area 5 (Fig. 1) (group of indicators P2-P8); then calculate the difference between the arithmetic mean of P2-P8 and P1; if this difference is less than or equal to 12%, they conclude that there is clinically significant chronic kidney disease; if this difference is greater than 12%, but less than 19%, they conclude that the patient has no clinically significant chronic kidney disease.

Example 1. Patient K., 19 years old

Hospitalized in the surgical department of the OGBUZ "Clinical Hospital No. 1" on February 01, 2020 with a diagnosis on admission: Urolithiasis.

During high-frequency ultrasound examination of the skin of the palmar surface of the distal phalanx of the middle finger, the percentage of pixels in acoustic lines (P1) in the dermis and subcutaneous fat was recorded. 15 seconds after the onset of the venous phase, contrast-enhanced ultrasound examination of the kidneys with a repetitive interval of 30 seconds recorded 7 indicators of the percentage of pixels on the ultrasound image (P2-P8) in the dermis and subcutaneous fat.

The difference between the arithmetic mean of the P2-P8 indicators and the P1 indicator was determined. The difference was 25.44%. The resulting figure is more than 19%.

Conclusion: No ultrasound signs of chronic kidney disease of 3-5 stages were found, no disturbances of peripheral microcirculation were found. The clinical diagnosis is supplemented.

Example 2. Patient L., 29 years old

Hospitalized in the surgical department of OGBUZ "Clinical Hospital No. 1" on November 27, 2019 with a diagnosis on admission: Chronic pyelonephritis, exacerbation stage. Kidney urolithiasis.

During high-frequency ultrasound examination of the skin of the palmar surface of the distal phalanx of the middle finger, the percentage of pixels in acoustic lines (P1) in the dermis and subcutaneous fat was recorded. 15 seconds after the onset of the venous phase, contrast-enhanced ultrasound examination of the kidneys with a repetitive interval of 30 seconds recorded 7 indicators of the percentage of pixels on the ultrasound image (P2-P8) in the dermis and subcutaneous fat.

The difference between the arithmetic mean of the P2-P8 indicators and the P1 indicator was determined. The difference was 18.6%. The resulting figure is more than 12%, less than 19%.

Conclusion: No ultrasound signs of chronic kidney disease of 3-5 stages were found, no disturbances of peripheral microcirculation were found. To identify chronic kidney disease stage 1-2, additional clinical and laboratory examination is required. The clinical diagnosis is supplemented.

Example 3. Patient N., 45 years old

Hospitalized in the chronic hemodialysis department of OGBUZ "Clinical Hospital No. 1" on March 10, 2019 with a diagnosis of Chronic pyelonephritis. Chronic kidney disease stage 4 (glomerular filtration rate 17 ml / min / 1.73 m3). Increase in blood pressure of I degree, risk 3. Anemia of mixed nature, 1 degree of severity.

During high-frequency ultrasound examination of the skin of the palmar surface of the distal phalanx of the middle finger, the percentage of pixels on the ultrasound image (P1) in the dermis and subcutaneous fat was recorded. 15 seconds after the onset of the venous phase, contrast-enhanced ultrasound examination of the kidneys with a repetitive interval of 30 seconds recorded 7 indicators of the percentage of pixels on the ultrasound image (P2-P8) in the dermis and subcutaneous fat. The difference between the arithmetic mean of the P2-P8 indicators and the P1 indicator was determined. The difference was 11.62%. The resulting figure is less than 12%.

Conclusion: Chronic kidney disease stage 3-5, impaired peripheral microcirculation. The clinical diagnosis is supplemented.

A method for assessing chronic kidney disease of stages 3-5 with the combined use of contrast-enhanced ultrasound of the kidneys and high-frequency ultrasound of the skin was carried out in 22 patients with diabetes mellitus (types 1 and 2) and suspected chronic kidney disease (stages 1-2). Early stages (1-2) of chronic kidney disease were revealed in 6 patients, in whom the known research methods did not reveal diffuse kidney pathology. Thus, the proposed method allows at an early stage of development of complications in the form of chronic kidney disease and start drug therapy.

Thus, the conclusions obtained using the proposed method for assessing clinically significant chronic kidney disease with the combined use of contrast-enhanced ultrasound of the kidneys and high-frequency ultrasound of the skin allow

supplement the patient's clinical diagnosis to build further tactics of his treatment and observation.

The proposed method for assessing chronic kidney disease stages 3-5 with the combined use of contrast-enhanced ultrasound of the kidneys and high-frequency ultrasound of the skin allows detecting violations of peripheral microcirculation at the screening stage, by conducting high-frequency ultrasound of the skin of the palmar surface of the distal phalanx of the middle finger with the determination of the percentage ratio pixels (P1) in the skin area 5 (Fig. 1) with repeated determination of the percentage of pixels (P2-P8) in the ultrasound image in the skin area 5 (Fig. 1) 15 seconds after the onset of the venous phase in contrast-enhanced ultrasound examination kidneys with an interval of 30 seconds, determining the difference between the arithmetic mean of the indicators P2-P8 and P1.

The advantages of this method are a decrease in the level of invasiveness, a reduction in the time for assessing the state of peripheral microcirculation, the possibility of conducting a semi-quantitative assessment of pathological changes at the screening stage.

Claims (1)

A method for assessing chronic kidney disease stages 3-5, including an ultrasound examination of the skin with a high-frequency sensor on the palmar surface of the distal phalanx of the middle finger of the left hand, in which an ultrasound image of a skin area is displayed on the monitor of an ultrasound machine with visualization of the dermis and subcutaneous fat, followed by assessment the percentage of the number of echo-positive and echo-negative pixels in the ultrasound image area - indicator P1; then, at the beginning of the venous phase of the contrast-enhanced ultrasound of the kidneys, timing is started, 15 seconds are counted, and a high-frequency ultrasound of the skin is performed 7 times every 30 seconds with an assessment of the percentage of the number of echo-positive and echo-negative pixels in the ultrasound image of the skin area - the group of indicators P2-P8; then calculate the difference between the arithmetic mean of P2-P8 and P1; if this difference is less than or equal to 12%, they conclude that the patient has chronic kidney disease of 3-5 stages, if this difference is more than 12%, but less than 19%, they conclude that the patient has no chronic kidney disease of 3-5 stages.

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