[Methods of cardiac output determination during extracorporeal detoxication]. / Metody opredeleniia serdechnogo vybrosa pri provedenii ékstrakorporal'noi detoksikatsii.

Two new methods of determining the cardiac output (CO) in extracorporeal detoxication (ECD) by thermal dilution were verified. The CO values, determined by the dilution of electrical impedance indicators (COimp) and by COimp thermal dilution (COtd), were compared within 31 matched analysis in 20 patients. The correlation coefficient: r = 0.98; n = 31; COtd = 0.98*, COimp + 0.19 (p < 0.01). The CO values, determined by ultrasound dilution (COus) and by thermal dilution (COtd), were compared within 31 matched analysis in 11 patients. The correlation coefficient: r = 0.97; COus = 1;* COtd = 0.32, (p < 0.01).

In vivo measurement of hemodialyzer fiber bundle volume: theory and validation.

BACKGROUND: Fiber bundle volume (FBV), the space within the blood compartment of hollow fiber dialyzers, may decrease during treatment due to clotting. The clots may be flushed out of the dialyzer prior to measurements of FBV by dialyzer reprocessing equipment and a significant drop in FBV during the session may go unrecognized. METHODS: FBV was measured (1) from the transit time of a saline bolus passing through the dialyzer as recorded by ultrasound dilution sensors placed on the arterial and venous blood lines; (2) from the change in blood concentration induced by a step change in the rate of ultrafiltration as recorded by the venous sensor. RESULTS: In vitro FBV ranged from 47 to 121 ml. Paired absolute differences between the ultrasound and volumetric measurements (flushing saline out of the dialyzer into a graduated cylinder) were 0.16 +/- 4.23% (N = 42) and 2.10 +/- 7.26% (N = 13) for the bolus and ultrafiltration methods, respectively. In vivo reproducibility of the bolus and ultrafiltration methods were 2.65 +/- 2.11% (N = 122) and 3.79 +/- 3.93% (N = 32), respectively. During 31 treatments the FBV by dilution showed an average decrease of 4.17 +/- 8.60%, and in 6 cases FBV fell more than 10%, while measurements of the same FBV by reuse equipment showed an increase of 0.99 +/- 5.82%, P < 0.01. CONCLUSIONS: FBV measured by the dilution methods was accurate and reproducible. Preliminary results suggest that in vivo FBV may differ significantly from results reported by reprocessing machines.

Volume of extravascular lung fluid determined by blood ultrasound velocity and electrical impedance dilution.

A hypertonic sodium chloride bolus passing through the lung has a sound velocity transient that is biphasic when it reaches the carotid artery. This transient is compatible with water moving into the hypertonic bolus from the lung parenchyma, thereby leaving the lung parenchyma hypertonic. Subsequently, as the bolus leaves the lung vasculature, water passes from the blood into the tissue to return the lung tonicity to baseline, giving a moment when net movement is zero, an instant of osmotic equilibrium. Concurrent measurements of impedance track the sodium chloride transient. A theoretic basis for the calculation of extravascular lung water is derived from the water transferred to the blood, the amount of sodium chloride moved from blood to the lung, and the increase in blood osmolarity measured at the moment of equilibrium. Examples from measurements on sheep suggest that two intravenous injections of hypertonic and isotonic sodium chloride, with observations of sound velocity and electrical impedance in the systemic arterial circulation (which could also provide the cardiac output), provide a basis for calculation of lung permeability, water and salt movements, and extravascular lung water estimation.

[The determination of cardiac output by the dilution of ultrasonic blood density]. / Opredelenie serdechnogo vybrosa metodom razvedeniia ul'trazvukovoi plotnosti krovi.

The authors propose assessing cardiac output (CO) by diluting the blood ultrasonic properties. For measuring CO, the peripheral artery and vein were connected with a catheter, and ultrasonic flowmetric pickup was attached to the shunt. Indicator (0.9% sodium chloride) was injected into the central vein. Changes in the blood ultrasonic characteristics during the indicator flow were recorded by ultrasonic flowmeter. Dilution curves were computer processed. The method was tried in 7 experimental dogs and clinically in 11 patients and compared with the thermodilution method. The coefficient of correlation was 0.98 in experiment and 0.97 in clinical trials. Dilution of ultrasonic density of the blood helps accurately assess the CO and is highly informative, which is confirmed by a strong correlation with the results of thermodilution. The method is simple, little invasive, realized using available equipment, the indicators are cheap and available, and repeated studies can be performed within short periods of time.

Simultaneous separate assessment of the cardiac and LVAD output.

The electroimpedance indicators' dilution (EIID) technique was used to study the possibility of a simultaneous separate assessment of the biological heart and LVAD performance in the position of LVB. The experimental part of the research was performed on 5 dogs; an artificial ventricle of the pulsing type (USA) with cusps was used as a pump. The clinical part of the work was conducted on 5 patients after open-heart surgery who had the clinical picture of postcardiotomy cardiogenic shock; a centrifugal pump "Biopump" (Medtronic, USA) was used. The authors have shown a principally important possibility of applying the EIID, technique for studying the performance curves which are the integral derivatives of the work of a specific hybrid system--"the biological heart-assist device". From the practical viewpoint the EIID technique permits in the read time mode to control continuously the part of the pumping function which is assumed by the patient's own heart. This information can serve as the basis for making the prognosis and determining the further tactics of treatment; the restoration of the heart performance or its replacement by transplantation.

[Dynamics of the content of the pulmonary extravascular fluid during extracorporeal detoxication in critical state patients]. / Dinamika pokazatelia ob"ema vnesosudistoi zhidkosti legkikh pri provedenii ékstrakorporal'noi detoksikatsii u bol'nykh v kriticheskikh sostoianiiakh.

Time course of the content of interstitial, cellular, and total fluid in the lungs, of plasma osmolality and sodium concentration was studied in 20 patients with acute renal failure after repair surgery on the heart, thoracic and abdominal organs. Water balance of the lungs was studied by dissolution of electroimpedance indicators before and after removal of 2000-2500 ml of ultrafiltrate. Ultrafiltration of the blood in the course of hemodialysis (group 1) did not lead to a reliable reduction of the volume of intravascular fluid, whereas in group 2 a reliable reduction of the volume of interstitial fluid of the lungs by 34% and of the total liquid volume of the lungs by 29% occurred in the course of hemofiltration.

[The electrical impedance indicator dilution method in studying the basic hemodynamic parameters during dialysis]. / Metod razvedeniia élektroimpedansnykh indikatorov v issledovanii osnovnykh parametrov gemodinamiki vo vremia dializa.

The procedure for measuring cardiac output and circulating blood volume is based on blood ability to modify its electrical conductance due to the amount of introduced ions (0.9% sodium chloride solution) or undissociated molecules (5% glucose solution). The cardiac output and circulating blood volume were calculated after measuring an area under the electrical impedance indicator dilution curve using the given formulas. With the described and thermodilution methods, the cardiac output was compared (r = 0.95). The correlation factor with the radioisotopic method in measuring the circulating blood volume was 0.88. Clinical investigations carried out in 47 patients on a programmed hemodialysis showed a significant decrease in cardiac output approximately by 700 ml/mi (7.9%) and circulating blood volume by an average of 900 ml (15.2%) by the end of a hemodialysis session, the rate of the circulating blood volume to body weight being also decreased. There was a predominant fluid "release" from the vascular bed.

[The use of a vitamin and metabolite complex for correcting the disorders in systemic and organ hemodynamics during liver resection under conditions of acute blood loss]. / Primenenie kompleksa vitaminov i metabolitov dlia korrektsii narushenii sistemnoi i organnoi gemodinamiki pri rezektsii pecheni v usloviiakh ostroi krovopoteri.

The efficacy of some infusion media, vitamins, and metabolites in resection of the liver in acute blood loss was studied in experiments on dogs. Inclusion of vitamins B1, B2, and B6, lipoic acid, calcium pantothenate, nicotinamide, solution of alpha-glutamate and gamma-aminobutyric acid (aminalone) in the infusion led to a sharp increase of myocardial contractility, increase of cardiac output and total hepatic blood flow, normalization of biochemical blood values, and restoration of the activity of hepatocyte enzymes.

[Possibilities of the method of dilution of electro-impedance indicators in the assessment of volume dynamics of extravascular lung fluid in intensive care and resuscitation units]. / Vozmozhnosti metoda razvedeniia élektroimpedansnykh indikatorov dlia otsenki dinamiki ob"ema vnesosudistoi zhidkosti legkikh v praktike otdeleniia intensivnoi terapii i reanimatsii.

The possibility of using impedance plethysmography to assess changes in the volume of the extravascular lung fluid in intensive therapy and resuscitation patients is discussed. Changes in the volume of the fluid during extracorporeal detoxication are analysed. A correlation was found between these changes and lung distensibility (r = -0.7). A significant diminution of the fluid volume was observed in response to therapeutic doses of Lasix and Nitroglycerin. Data are cited on the increasing (85 percent) volumes of the fluid in preclinical pulmonary edema in patients with left ventricular insufficiency.

[Study of parameters of central hemodynamics in patients during hemodialysis]. / Issledovanie parametrov tsentra'lnoi gemodinamiki u bo'lnykh vo vremia gemodializa.

The article discusses the results of study of the cardiac output (CO) and circulation blood volume (CBV) in patients at the beginning and end of hemodialysis. The dynamics of changes of these parameters during hemodialysis was studied in 31 patients (42 sessions). The CO and CBV reduced significantly. In a group of 10 patients who felt worse, the CO reduced by more than 30 per cent in 7, the CBV diminished by 25 and 30 per cent in 2, and CBV and CO reduced by more than 30 per cent in 1 patient in relation to the initial level. The CO and CBV were measured by means of the method of dilution of electroimpedance indicators.

[Determination of hemodynamic parameters by blood electrical resistance using a dilution method]. / Opredelenie parametrov gemodinamiki po élektricheskomu soprotivleniiu krovi metodom razvedeniia.

The theoretical basis and the experimental data of the hemodynamic parameter determination method have been described. The cardiac output and the circulating blood volume have been determined using intravenous injections of two solutions with different electrical resistance. A formula for blood electrical resistance was proposed. Tolerances for isoosmotic solutions were made. A system of three equations was made up on the basis of the results of two injections of solutions with different electrical conductance. From these equations blood characteristics, cardiac and circulating blood volumes can be obtained. Isoosmotic solutions of glucose and sodium chloride were used as indicators in treadmill tests with circulating blood. The measurement error practically didn't depend on the electrode type (either along or across the flow).

[Determination of the volume of extravascular fluid in the lungs by blood electrical resistance using a dilution method]. / Opredeleneie ob''ema vnesosudistoi zhidkosti v legkikh po élektricheskomu soprotivleniiu krovi metodom razvedeniia.

The theoretical basis of the method determining the volume of the extravascular lung fluid has been considered. The fluid volume is found by measuring the volume of water passing from the lung into the blood through the hyperosmotic indicator. The water volume is determined by comparing the curves of electrical resistance obtained as a result of intravenous injections of isoosmotic and hyperosmotic solutions. The electrical resistance of the blood is measured in the arterial bed. The lung fluid volume can be calculated using the parameters of the dilution curves and the equation for the crossing point.