SU519886A1 - Method of obtaining blood sample at radioisotope determination of the blood quantity circulating in organism - Google Patents

Description

one

 This invention relates to medicine, in particular to functional radioisotope diagnostics.

In order to determine the amount (volume) of blood circulating in the body, it is usually necessary to obtain a blood sample containing a radioactive indicator, the dilution of which in the sample corresponds to its dilution in the whole mass of circulating blood. In this case, the total amount of the indicator in the volume of circulating blood, and its dilution in a blood sample, found by measuring the radioactivity of the sample, is easy to calculate the volume of circulating blood.

A known method for obtaining a blood sample according to which it is proposed; Intravenous administration of a radioactive indicator to the subject and subsequent collection of a blood sample from the subject's vein some time after the indicator was injected, sufficient to evenly distribute the latter in the whole mass of the circulating blood 1.

In one of the known methods, an isotope labeled with isotope was administered intravenously as an indicator.

A blood sample was taken from the test subject's vein 10-15 minutes after the introduction of the indicator. .2.

However, this method is characterized by a relatively large radiation load of radioactive albumin on the test subject’s organism, which is ensured by the ability of albumin

0 long circulate in the bloodstream. This circumstance significantly limits the applicability of the known method in pediatrics.

five

In order to reduce the radiation load on the body of the test person, the sodium salt of ortho-U-hippuric acid Ggyppuran-U) is used as an indicator and blood sample is taken.

0 is carried out in the interval between the first and second minutes after the introduction of the indicator.

At research of volume of the circulating krrvi hippuran -. introduced into

Claims (2)

5 bloodstream. At the same time, the level of radioactivity is recorded using a sensor installed in the precordial region and the recording device. After 1-1.5 minutes, blood samples are taken from the ulnar vein and the concentration of the radioactive indicator in 1 ml of blood is determined according to radiometry data. The value obtained is increased by the degree of decrease in the height of the cryrai, the level of radioactivity from, from g the moment of introduction of the indicator to the moment of taking blood samples. This amendment makes it possible to eliminate the error associated with the departure of the indicator into the so-called hippuranic space and through the kidneys. It was found that the height of the radioactivity level curve of the precardiac area on the 30th s after administration of hippuran is close in its value to the height of the analogous curve obtained using albumin-corresponding to its full dilution in the bloodstream. Knowing more than the amount of radioactive hippuran introduced into the bloodstream, and the concentration of hippuran in 1 ml of blood, as amended, it is easy to calculate the volume of q, circulating blood. A blood sample must be taken between the first and second minutes after the introduction of the indicator. Earlier blood collection is undesirable due to the fact that the hippuran is not yet mixed with the whole mass of blood. A later blood draw leads to an error related to the ability of this substance to escape into paravascular space. It should be noted that such an error also occurs if a blood sample is taken between the first and second minutes after the administration of the indicator. However, at this time, the amount of indicator leaving the blood into the paravascular space is still insignificant, as confirmed by the small difference in the results of determining the volume of circulating blood using the proposed method and the subsequent determination of the volume of circulating blood using radioactive albumin on the same organism . PRI mery A test patient was intravenously injected with 20 µC. radioactive hippurana. A parallel recording of the level of radioactivity is carried out with the aid of a sensor installed in the pre-cardiac area and a recording device. 1.5 min after the introduction of the indicator, a blood sample is taken from the elbow, howling vein. The height of the curve on the 30th second after the introduction of hippuran is 12 mm. The height of the curve after 1.5 minutes (time of blood collection) is 10 mm. The radioactivity of the introduced hippuran is 6000000 imp / min. The radioactivity of 1 ml was taken 1.5 minutes after administration of blood hippuran 1000 imp / min. The volume of circulating blood is equal to BOOOOOO10 5000 ml. 1000-12 The proposed method reduces the radiation load by almost 60 times compared with the method associated with the use of radioactive albumin. This greatly enhances the possibility of repeated studies in patients with the category of PD and in pediatric practice. The proposed method also makes it possible to study the indicator of circulating blood volume together with other central hemodynamic indicators. The method of obtaining a blood sample in a radioisotope determination of the amount of blood circulating in the body, including the intravenous administration of a radioactive indicator to the subject and the subsequent selection of a blood sample from the subject's vein, characterized in that, in order to reduce the radiation load on the body of the subject, the indicator is entered The sodium salt of ortho-U-hippuric acid and the sample of cvvwi are carried out in the interval between the first and second minutes after the introduction of the indicator. Sources of information taken into account during the examination 1. Abramov N.G. and other Handbook of functional diagnostics, m., 1970, p. 214-215. 2.Mapov G.A. and others. Journal of Medical Radiologists .1974, № 2, p. 42-47 (prototype).