�ber die ?thermo-dilution?-Methode zur Bestimmung des Herzzeitvolumens am narkotisierten und unnarkotisierten Hund

Klussmann, F. W.; Koenig, W.; Lütcke, A.

doi:10.1007/bf00362208

Cited by 22 publications

(4 citation statements)

References 10 publications

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“…o Für die gemessene Konzentrationszeitkurve -bei Elimination -ergibt sich analog zur obigen Formel (6) Die LOGNORMAL-NLSQ-Technik Es sei die "defekte" Transportfunktion g eine Funktion dergestalt: (7) mit der Durchlässigkeit des Systems p<l (der Anteil der Teilchen die pro Zirkulation eliminiert werden) und der Transportfunktion h. Für die mittleren Transitzeit MTT gilt: .o· o--·-·-· Die "defekte" Transportfunktion sei g, für die gilt: .…”

Section: Theorie Der Lognormal-nlsq-technikunclassified

LOGNORMAL-NLSQ-Technik - Überprüfung einer neuen mathematischen Methode zur Bestimmung des Blutvolumens - LOGNORMAL-NLSQ Technique Investigation of a New Mathematical Method of Calculating Blood Volume

Schröder

Rösler²,

Hahn³

et al. 1997

Biomedizinische Technik/Biomedical Engineering

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Schlüsselwörter: Blutvolumen, LOGNORMAL-NLSQ-Technik, RezirkulationIn dieser Arbeit wird eine neue mathematische Methode zur Blutvolumenbestimmung überprüft. Das neue Verfahren beruht auf der Bestimmung des Blutvolumens mit Hilfe des Produktes aus mittlerer Kreislauftransitzeit (Umlaufzeit des Blutes) und Herzzeitvolumen. Die mittlere Kreislauftransitzeit wird aus der Körpertransportfunktion berechnet. Um die Genauigkeit dieser LO-GNORMAL-NLSQ-Technik zu überprüfen, wurden 45 Konzentrationszeitkurven in einem Invitro-Rezirkulationsmodell bei variabler Clearance gemessen. Das berechnete Volumen war im Mittel um 4 Prozent niedriger als das tatsächliche Volumen. Dieser Fehler läßt sich auf funktioneile Toträume innerhalb des Modells zurückführen und ist in der Praxis tolerierbar. In Zukunft könnte die LOGNORMAL-NLSQ-Technik in der Klinik eine große Rolle spielen, besonders aufgrund der sehr schnellen und genauen Ergebnisse. This paper describes the investigation of a new mathematical method of calculating blood volume. The new method determines the blood volume by calculating the product of the mean circulation transit time. The mean transit time is calculated from the body transport function. To examine the accuracy of the LOGNORMAL-NLSQ technique, 45 concentration time curves were measured in an in vitro recirculation model with variable clearance. The calculated volume was 4 % smaller than the actual volume. This may be attributed to the functional dead space within the model, and is tolerable for clinical situations. The LOGNORMAL-NLSQ technique might acquire considerable importance in future, especially since it provides accurate results very quickly.

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Section: Theorie Der Lognormal-nlsq-technikunclassified

LOGNORMAL-NLSQ-Technik - Überprüfung einer neuen mathematischen Methode zur Bestimmung des Blutvolumens - LOGNORMAL-NLSQ Technique Investigation of a New Mathematical Method of Calculating Blood Volume

Schröder

Rösler²,

Hahn³

et al. 1997

Biomedizinische Technik/Biomedical Engineering

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“…The regression equation for 47 experiments was found to be COrd = 0.95 COnek + 0.08; the correlation coefficient was 0.94.The thermal dilution method for estimating cardiac output, introduced by Fegler (5), is commonly used both in man (2,8,17) and animals (10,14,15,20,21). The purpose of this study was to validate in dog experiments a method for thermal dilution measurement which employs a double-thermistor catheter combined with an automatic computer as described by 01sson et al Dilution and injectate temperature are entered directly into the calculation.…”

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“…The thermal dilution method for estimating cardiac output, introduced by Fegler (5), is commonly used both in man (2,8,17) and animals (10,14,15,20,21). Pulmonary detection and right atrial injection of indicator is usually preferred over other injection and detection sites (13, 24); proper mixing of the indicator over the short distance is achieved by the mechanical action of the right ventricle (22).…”

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confidence: 99%

Thermal dilution measurement of cardiac output in dogs using an analog computer

1978

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Thermal dilution cardiac output determinations in dogs were compared to simultaneously performed Fick oxygen measurements. The purpose of this study was to validate in dog experiments a method for thermal dilution measurement which employs a double-thermistor catheter combined with an automatic computer as described by Olsson et al. Dilution and injectate temperature are entered directly into the calculation. The method does not employ logarithmic extrapolation, integration of the dilution signal being terminated when a preset cut-off level is reached. Errors due to recirculation, thermal capacitance of the right heart and heat exchange with the catheter's dead space require the use of an empirically derived correction factor, which in dogs was found to be significantly different from the factor used for human thermal dilution curves. With the appropriate cut-off level and correction factor a good agreement was found between the results of the thermal dilution and the Fick method. The regression equation for 47 experiments was found to be COtd = 0.95 COFick + 0.08; the correlation coefficient was 0.94.

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“…There was a wide range in doses of histamine applied, in methods used for determining circulatory parameters and in laboratory animals involved, and the results obtained were often contradictory. Cardiac output was calculated with the thermodilution method [4,5]. (3) Do H1-and Ha-receptor antagonists alter the actual plasma histamine levels?…”

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confidence: 99%

Alterations in the circulatory system of anaesthesized dogs following administration of histamine and histamine H1- and H2-receptor antagonists in relation to plasma histamine levels

et al. 1975

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The effects of histamine on the circulatory system have been the subject of a great number of investigations [1]. There was a wide range in doses of histamine applied, in methods used for determining circulatory parameters and in laboratory animals involved, and the results obtained were often contradictory. In order to contribute to the main problem whether endogenous histamine is involved in pathophysiological or clinical stituations it was the aim of the present study to answer the following questions:(1) Do the effects of histamine in the circulatory system depend on the actual histamine levels?(2) How do H1-and H2-receptor antagonists influence the histamine actions? (3) Do H1-and Ha-receptor antagonists alter the actual plasma histamine levels? MethodsThe experiments were carried out in 23 mongrel dogs (both sexes, 14-28 kg body weight) which were anaesthesized with pentobarbitone and breathed room air spontaneously. The acid-base balance and the body temperature were controlled.Aortal plasma histamine concentration was measured by a specific ftuorometric test [2,3]. Blood pressure was recorded in aorta, pulmonal artery, portal vein and inferior caval vein by Statham strain gauges and was determined at end exspiration. Blood flow in the superior mesenteric artery and hepatic artery was estimated using electromagnetic flow meters (Statham). Cardiac output was calculated with the thermodilution method [4,5]. Resistance in several regions of the vascular bed was calculated from the equation R = Ap/Q 9 kg body weight [6]. Pulse rate and breath rate were counted from the blood pressure curves recorded.The experiments were started 30 minutes after completing the operation (laparotomy, insertion of catheters, flow probes and the thermistors, calibrations).Only one dose of histamine (10 ~g/kg histamine dihydrochloride corresponding to 6 ~g/kg histamine base) was injected into the inferior caval vein. 30 minutes later 5 mg/kg dimethpyrindene (Zyma-Blaes, Munich) or 10 mg/kg burimamide (SK & F, Welwyn Garden, UK) were administered into the same vein. 10 minutes later on again 6 ~-g/kg histamine base were applied. Blood samples for plasma histamine assay were taken immediately before and 30 seconds after the injection of histamine. Results(a) Effects of a single dose of histamine (6 sg/kg on plasma histamine levels and circulatory parameters (Table 1) The plasma histamine concentration increased by about 6000% though the dose of histamine applied (about 120 ~g/animal) by no means was life-threatening or even fatal to the dogs.Cardiac output and pulse rate were not altered, but arterial and central venous pressures as well as total systemic resistance decreased considerably. Since arterial pressure and total systemic resistance decreased to the same extent the effect of this dose of histamine on the mean aortal pressure was mainly caused by peripheral vasodilatation and not by negative inotropic action of histamine on the heart.At the time of maximum aortal hypotension there was no increase in pulmonal arterial pressur...

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�ber die ?thermo-dilution?-Methode zur Bestimmung des Herzzeitvolumens am narkotisierten und unnarkotisierten Hund

Cited by 22 publications

References 10 publications

LOGNORMAL-NLSQ-Technik - Überprüfung einer neuen mathematischen Methode zur Bestimmung des Blutvolumens - LOGNORMAL-NLSQ Technique Investigation of a New Mathematical Method of Calculating Blood Volume

LOGNORMAL-NLSQ-Technik - Überprüfung einer neuen mathematischen Methode zur Bestimmung des Blutvolumens - LOGNORMAL-NLSQ Technique Investigation of a New Mathematical Method of Calculating Blood Volume

Thermal dilution measurement of cardiac output in dogs using an analog computer

Alterations in the circulatory system of anaesthesized dogs following administration of histamine and histamine H1- and H2-receptor antagonists in relation to plasma histamine levels

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