RU2081413C1 - Method for determining tissular breathing reserve capability - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves determining cation and anion concentrations difference in patient arterial blood followed by evaluating this parameter in two directions. To evaluate the present health state of the patient, cation and anion concentrations difference in patient arterial blood sample is compared with the upper limit of the set of normal values of this parameter, being equal to 11 mmole/l. The patient cation and anion concentrations difference exceeding value, anaerobic breathing mechanism and reduced tissular breathing reserves are concluded to be present already at the rest state. To evaluate patient state dynamics, cation and anion concentrations difference in patient arterial blood sample is compared with the value of this parameter measured in previous samples. Cation and anion concentrations difference growing up trend being observed, conclusion about growing significance of anaerobic breathing mechanism contribution to the general tissular breathing process is to be made. Falling cation and anion concentrations difference trend being observed, relative tissular breathing normalization is to be concluded to take place. EFFECT: wide range of applications in estimating health state. 1 dwg

Description

 The invention relates to medicine, in particular, to the diagnosis of respiratory diseases.

 A known method for determining the reserve capacity of tissue respiration by fixing the moment of a sharp increase in the concentration of lactate in mixed venous blood during exercise on the subject (see Cynthia B. Kremser, Sol I. Raifer. The Normal Cardiovascular to Exercise. In Alan R. Leff: Cardiopulmonary Exercise Testing, 1986, p. 114).

 There is also a method of determining the reserve capacity of tissue respiration by fixing the moment of a sharp increase in carbon dioxide emissions compared with oxygen consumption during exercise (see Cynthia B. Kremser, Sol I. Raifer. The Normal Cardiovascular Response to Exercise. In Alan R. Leff : Cardiopulmonary Exercise Testing, 1986, p. 114).

 These methods are used in people who can tolerate physical activity, and are extremely difficult in patients with respiratory failure, concomitant diseases of the cardiovascular system and in elderly patients.

 However, the establishment of the fact of the presence of anaerobic mechanisms of tissue respiration is of great importance for the diagnosis and treatment of respiratory failure.

 In the practice of assessing the acid-base state, it is known to use the determination of the difference of cations and anions in venous blood, for the sole purpose of assessing the acid-base state (see Ruth G. Acid-base condition and electrolyte balance. Transl. From English. Moscow: Medicine, 1978 , p. 35).

 The aim of the invention is to establish the presence of anaerobic mechanisms in patients with respiratory failure, in particular, with contraindications to physical activity.

 This goal is achieved by taking a sample of arterial blood and determining the difference in the concentration of cations and anions in it, and with the increase of this indicator above 11 mmol / l, the appearance of anaerobic respiration mechanisms is recorded.

 The drawing shows the dependence of the difference in the concentrations of anions and cations in arterial blood and oxygen consumption by tissues.

 The method is illustrated by the following specific examples of its implementation.

 Example 1. Patient B. 31. The patient revealed chronic obstructive bronchitis, pulmonary emphysema, pneumosclerosis, respiratory failure of 1 degree.

The patient was sampled arterial blood from the radial artery using an arterial syringe in an amount of 1 ml. The patient's arterial blood was analyzed with a 288 Blood Gas System analyzer of gas, electrolyte and acid-base blood composition from Ciba Corning Diagnostic Corp. (United Kingdom). The following arterial blood parameters were measured:
pH 7.38;
pO ₂ 91.9 mm Hg Art. partial pressure of oxygen;
pCO ₂ 43.7 mmHg Art. partial pressure of carbon dioxide;
[Na ⁺ ] 137 mmol / L concentration of sodium ions;
[K ⁺ ] 3.81 mmol / L potassium ion concentration;
[Cl ^- ] 106 mmol / L concentration of chlorine ions.

The following arterial blood parameters were calculated:
[HCO3-] 25.9 mmol / L bicarbonate ion concentration;
the difference in the concentration of cations and anions is 9 mmol / l;
according to the formulas:
(pH 6.1)
[HCO3-] 0,031 • pCO ₂ • 10
The difference in the concentration of cations and anions ([Na ⁺ ] + [K ⁺ ]) - ([Cl ^- ] + [HCO3-).

 The values of oxygen consumption at the time of the onset of the anaerobic threshold were determined by the method of ergospirometry: VO2 (AT) 1.07 l / min.

 Evaluation of patient data was carried out using the graph obtained by us, presented in FIG. 1. The graph represents the dependence of the oxygen consumption at the time of the anaerobic threshold on the difference in the concentrations of anions and cations of arterial blood taken alone. The graph shows that the relationship between these two parameters is a linear inversely proportional relationship. It is known that the value of oxygen consumption at the time of the onset of the anaerobic threshold in a healthy person should exceed at least 1 l / min. The graph shows that this value corresponds to the difference between the cations and anions of arterial blood, measured at rest, equal to 11 mmol / L. An increase in the difference in the concentrations of cations and anions of arterial blood taken alone, above 11 mmol / l, indicates the presence of anaerobic mechanisms of tissue respiration already at rest, i.e. a decrease in the reserve capacity of tissue respiration. The data for this patient is described by point 1 on the graph. The value of the difference between the cations and anions of the arterial blood of this patient, equal to 9 mmol / L, does not exceed the normal value (11 mmol / L), so we can conclude that there is no anaerobic respiration in this patient at rest.

 Example 2. Patient K. 28 l. The patient revealed a bilateral focal disseminated process in the lungs, respiratory failure of 2 degrees.

 The patient was examined according to the method described in example 1.

The following results were obtained:
pH 7.359;
pO ₂ 75.3 mm Hg Art.

pCO ₂ 42.8 mmHg Art.

[Na ⁺ ] 139.3 mmol / L;
[K ⁺ ] 4.42 mmol / L;
[Cl ^- ] 107 mmol / L;
[HCO3-] 24.1 mmol / L;
the difference in the concentration of cations and anions is 12.6 mmol / L.

 VO2 (AT) 0.72 L / min.

 Patient data is described by point 2 in the graph in FIG. one.

 The value of the difference in the concentrations of cations and anions of the arterial blood of this patient exceeds 11 mmol / L, which indicates the presence of anaerobic respiration in the patient already at rest, i.e. a decrease in the reserve capacity of tissue respiration and is confirmed by a reduced oxygen consumption at the time of the anaerobic threshold.

 Example 3. Patient R. 46 L. The patient revealed chronic obstructive bronchitis / emphysema, respiratory failure of 1 degree.

 The patient was examined according to the method described in example 1.

The following results were obtained:
pH 7.426;
pO ₂ 59.2 mmHg Art.

pCO ₂ 39.6 mmHg Art.

[Na ⁺ ] 136.4 mmol / L;
[K ⁺ ] 3.83 mmol / L;
[Cl ^- ] 110 mmol / L;
[HCO3-] 26.0 mmol / L;
the difference in the concentration of cations and anions is 4.2 mmol / L.

 VO2 (AT) 1.81 L / min.

 Patient data is described by point 3 on the graph in FIG. one.

Assessing the oxygenation of the tissues of this patient by the traditional indicator of pO ₂ , it can be assumed that the delivery of oxygen to the tissues is insufficient. When comparing the data of this patient and the patient described in example 2 for this indicator, we can conclude that the supply of tissues with oxygen is less efficient in the second case. However, the determination of the value of oxygen consumption at the time of the anaerobic threshold indicates the presence of significant reserve tissue breathing capabilities in this patient (his defined VO2 (AT) equal to 1.81 l / min, significantly exceeds the VO2 (AT) of the patient described in the example 2, equal to 0.72 l / min). This conclusion can be obtained by evaluating the difference in the concentration of anions and cations in the arterial blood of the patient. The calculated value of this parameter for this patient, equal to 4.2 mmol / l, suggests that despite arterial hypoxemia, compensatory mechanisms allow for adequate tissue oxygenation (this patient has significant reserves of tissue respiration).

 The statistical analysis confirmed the presence of a linear inversely proportional relationship between the oxygen consumption at the time of the anaerobic threshold and the value of the difference in the concentrations of anions and cations in arterial blood.

,
R коэффициент корреляции;
m11 выборочный смешанный момент;
D (AG) дисперсия значений разности концентрации катионов и анионов в артериальной крови;
D (VO2) дисперсия значений VO2 (AT);
R=-0,60036/0,6693=0,897
Для проверки гипотезы о значимости полученного коэффициента корреляции мы воспользовались критериальной статистикой Фишера и получили доверительные границы для R:
-0,98 <R> -0,65
Предлагаемый способ определения резервных возможностей тканевого дыхания является, по существу, единственным, впервые предложенным способом, позволяющим зафиксировать наличие анаэробных механизмов тканевого дыхания у больных, не способных к физической нагрузке. Отличительной особенностью способа, имеющей принципиальную новизну, является определение разности концентраций катионов и анионов именно в артериальной крови, что позволяет установить наличие анаэробных механизмов дыхания, и производится впервые в медицинской практике, поскольку считалось целесообразным исследовать разность концентраций катионов и анионов исключительно в венозной крови.Calculation of the correlation coefficient:
the difference in the concentrations of anions and cations (mmol / l) VO2 (l / min)
4.2 1.81
11.7 0.66
10.1 0.99
8.8 1.1
12.9 0.89
9 1.07
12.6 0.72
10.3 1.16
11.4 0.96
10.7 1.11
11.4 0.94
To calculate the correlation coefficient, we used the following formula:

,
R is the correlation coefficient;
m11 selective mixed moment;
D (AG) the variance of the difference in the concentration of cations and anions in arterial blood;
D (VO2) the variance of the values of VO2 (AT);
R = -0.60036 / 0.6693 = 0.897
To test the hypothesis about the significance of the obtained correlation coefficient, we used Fisher's criterion statistics and obtained confidence limits for R:
-0.98 <R> -0.65
The proposed method for determining the reserve capacity of tissue respiration is essentially the only, first proposed method that allows you to record the presence of anaerobic mechanisms of tissue respiration in patients who are not capable of physical activity. A distinctive feature of the method, which is fundamentally new, is the determination of the difference in the concentration of cations and anions in arterial blood, which allows us to establish the presence of anaerobic respiration mechanisms, and is performed for the first time in medical practice, since it was considered advisable to study the difference in the concentration of cations and anions exclusively in venous blood.

 A new scientific fact has been established that the dependence of oxygen consumption at the time of the anaerobic threshold on the difference in the concentrations of anions and cations in arterial blood is objectively fixed, and the possibility of such objective registration was completely unobvious for a knowledgeable specialist in this field.

 The proposed method for determining the reserve capacity of tissue respiration allows the anaerobic respiration mechanisms to be detected without exercise due to the use of the parameter of the difference in the concentration of cations and arterial blood anions, which reflects the accumulation of acidic metabolic products in patients with reduced oxygen consumption. This method allows you to evaluate not only the current state of tissue respiration, but also to monitor in dynamics its changes during treatment. Since the method is applicable for patients incapable of performing physical activity, it can be used not only in the laboratories of functional diagnostics of the respiratory system, but also in intensive care units.

Claims (1)

A method for determining the reserve potential of human tissue respiration, including blood sampling with subsequent measurement of the level of a diagnostically significant component in comparison with a norm indicator, characterized in that arterial blood is sampled, the concentration of ions K ⁺ , Cl ^- , Na ⁺ , HCO is recorded $\genfrac{}{}{0ex}{}{\text{-}}{\text{3}}$ , then the difference in the concentrations of cations and anions is calculated, and with the value of this indicator in the blood of the subject above 11 mmol / l, the presence of anaerobic respiration mechanisms is determined.