Central venous pressure and mean circulatory filling pressure in the dogfish Squalus acanthias: adrenergic control and role of the pericardium

2006 ◽  
Vol 291 (5) ◽  
pp. R1465-R1473 ◽  
Author(s):  
Erik Sandblom ◽  
Michael Axelsson ◽  
Anthony P. Farrell
Keyword(s):  
Central Venous Pressure ◽  
Venous Return ◽  
Venous Pressure ◽  
Filling Pressure ◽  
Control Fish ◽  
Central Venous ◽  
Venous Capacitance ◽  
Mean Circulatory Filling Pressure ◽  
Adrenergic Control ◽  
Venous Vasculature

Subambient central venous pressure (Pven) and modulation of venous return through cardiac suction (vis a fronte) characterizes the venous circulation in sharks. Venous capacitance was estimated in the dogfish S qualus acanthias by measuring the mean circulatory filling pressure (MCFP) during transient occlusion of cardiac outflow. We tested the hypothesis that venous return and cardiac preload can be altered additionally through adrenergic changes of venous capacitance. The experiments involved the surgical opening of the pericardium to place a perivascular occluder around the conus arteriosus. Another control group was identically instrumented, but lacked the occluder, and was subjected to the same pharmacological protocol to evaluate how pericardioectomy affected cardiovascular status. Routine Pven was negative (−0.08 ± 0.02 kPa) in control fish but positive (0.09 ± 0.01 kPa) in the pericardioectomized group. Injections of 5 μg/kg body mass ( Mb) of epinephrine and phenylephrine (100 μg/kg Mb) increased Pven and MCFP, whereas isoproterenol (1 μg/kg Mb) decreased both variables. Thus, constriction and relaxation of the venous vasculature were mediated through the respective stimulation of α- and β-adrenergic receptors. α-Adrenergic blockade with prazosin (1 mg/kg Mb) attenuated the responses to phenylephrine and decreased resting Pven in pericardioectomized animals. Our results provide convincing evidence for adrenergic control of the venous vasculature in elasmobranchs, although the pericardium is clearly an important component in the modulation of venous function. Thus active changes in venous capacitance have previously been underestimated as an important means of modulating venous return and cardiac performance in this group.

Systemic filling pressure in intact circulation determined on basis of aortic vs. central venous pressure relationships

1994 ◽  
Vol 267 (6) ◽  
pp. H2255-H2258 ◽  
Author(s):  
E. A. Den Hartog ◽  
A. Versprille ◽  
J. R. Jansen
Keyword(s):  
Central Venous Pressure ◽  
Flow Resistance ◽  
Venous Pressure ◽  
Aortic Pressure ◽  
Filling Pressure ◽  
Central Venous ◽  
Mean Systemic Filling Pressure ◽  
Systemic Filling ◽  
The Mean ◽  
Systemic Filling Pressure

In the intact circulation, mean systemic filling pressure (Psf) is determined by applying a series of inspiratory pause procedures (IPPs) and using Guyton's equation of venous return (Qv) and central venous pressure (Pcv): Qv = a - b x Pcv. During an IPP series, different tidal volumes are applied to set Pcv at different values. From the linear regression between Qv and Pcv, Psf can be calculated as Psf = a/b. Guyton's equation can also be written as Qv = (Psf - Pcv)/Rsd, where Rsd is the flow resistance downstream of the places where blood pressure is equal to Psf. During an IPP, a steady state is observed. Therefore, we can also formulate the following equation for flow: Qs = (Pao - Psf)/Rsu, where Qs is systemic flow, Rsu is the systemic flow resistance upstream to Psf, and Pao is aortic pressure. Because both flows (Qs and Qv) are equal, it follows that Pao = Psf(1 + Rsu/Rsd) - Rsu/Rsd x Pcv. This equation implies a method to determine mean systemic filling pressure on the basis of Pao measurements instead of flow determinations. Using 22 IPPs in 10 piglets, we determined the mean systemic filling pressure, and we compared the values obtained from the flow curves with those obtained from the aortic pressure curves. The mean difference between the two methods was 0.03 +/- 1.16 mmHg. With the use of Pao measurements, the Psf can be estimated as accurately as in using flow determinations. The advantage of the new method is that estimation of cardiac output is not required.

Automatic regulation of the cardiopulmonary bypass

Perfusion ◽  
1986 ◽  
Vol 1 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Juro Wada ◽  
Tsunekazu Hino ◽  
Hideki Kaizuka ◽  
Wolfgang R Ade
Keyword(s):  
Cardiac Surgery ◽  
Cardiopulmonary Bypass ◽  
Central Venous Pressure ◽  
Venous Return ◽  
Venous Pressure ◽  
Experimental Studies ◽  
Automatic Regulation ◽  
Central Venous ◽  
Respiratory Change ◽  
Clinical Cases

We devised a new method and system for the automatic regulation of cardiopulmonary bypass. The system is planned so that it is regulated according to the alteration of venous pressure which is a reflection of venous return in total cardiopulmonary bypass. After many experimental studies, we have used this system in four clinical cases of cardiac surgery. The system functioned sufficiently well in the clinical cases. Under the control of this system, the central venous pressure was kept at a preset level and changed cyclically in the same manner as the respiratory change through the entire cardiopulmonary bypass period. A constant and adequate venous return through the entire cardiopulmonary bypass period was assumed to be the most important factor for the venous return-triggered pump oxygenator.

Possible equilibration of portal venous and central venous pressures during circulatory arrest

1993 ◽  
Vol 264 (1) ◽  
pp. H259-H261 ◽  
Author(s):  
R. Tabrizchi ◽  
S. L. Lim ◽  
C. C. Pang
Keyword(s):  
Circulatory Arrest ◽  
Venous Pressure ◽  
Filling Pressure ◽  
Intravenous Bolus ◽  
Ang Ii ◽  
Central Venous ◽  
Venous Tone ◽  
Mean Circulatory Filling Pressure ◽  
Anesthetized Rats ◽  
Total Body

The mean circulatory filling pressure technique has been used to assess total body venous tone. It involves measuring central venous pressure (CVP) at 5-8 s following circulatory arrest. This study examines if CVP and portal venous pressure (PVP) equilibrate when circulation is stopped by inflating a balloon implanted in the right atrium. CVP and PVP were measured in the control condition and after intravenous bolus injections of norepinephrine (NE, 1.6 microgram/kg), angiotensin II (ANG II, 1.3 microgram/kg), and isoproterenol (Iso, 0.5 microgram/kg) in conscious and pentobarbital-anesthetized rats. In conscious rats, CVP was similar to PVP after circulatory arrest under conditions of normal, elevated, or reduced vascular tone. In anesthetized rats, CVP was similar to PVP in the control condition and after intravenous bolus injection of NE and Iso but was less than PVP after the administration of ANG II. Therefore, mean circulatory filling pressure may not fully reflect total body venous tone in anesthetized, surgically stressed rats.

scholarly journals Defining human mean circulatory filling pressure in the intensive care unit

2020 ◽  
Vol 129 (2) ◽  
pp. 311-316
Author(s):  
Marije Wijnberge ◽  
Jaap Schuurmans ◽  
Rob B. P. de Wilde ◽  
Martijn K. Kerstens ◽  
Alexander P. Vlaar ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Venous Pressure ◽  
Filling Pressure ◽  
Central Venous ◽  
Venous Compliance ◽  
Icu Patients ◽  
Mean Circulatory Filling Pressure ◽  
Arterial Blood

In a cohort of 311 intensive care unit (ICU) patients, median mean circulatory filling pressure (Pmcf) measured after cardiac arrest was 15 mmHg (interquartile range 12–18). In 48% of cases, arterial blood pressure remained higher than central venous pressure, but correction for arterial-to-venous compliance differences did not result in clinically relevant alterations of Pmcf. Fluid balance, use of vasopressors or inotropes, and being on mechanical ventilation were associated with a higher Pmcf.

scholarly journals Central venous pressure and cardiac function during spaceflight

1998 ◽  
Vol 85 (2) ◽  
pp. 738-746 ◽  
Author(s):  
Ronald J. White ◽  
C. Gunnar Blomqvist
Keyword(s):  
Cardiac Output ◽  
Stroke Volume ◽  
Central Venous Pressure ◽  
Shape Change ◽  
Venous Pressure ◽  
Left Ventricular ◽  
Filling Pressure ◽  
Central Venous ◽  
End Diastolic Volume ◽  
Reference Measurements

Early in spaceflight, an apparently paradoxical condition occurs in which, despite an externally visible headward fluid shift, measured central venous pressure is lower but stroke volume and cardiac output are higher, and heart rate is unchanged from reference measurements made before flight. This paper presents a set of studies in which a simple three-compartment, steady-state model of cardiovascular function is used, providing insight into the contributions made by the major mechanisms that could be responsible for these events. On the basis of these studies, we conclude that, during weightless spaceflight, the chest relaxes with a concomitant shape change that increases the volume of the closed chest cavity. This leads to a decrease in intrapleural pressure, ultimately causing a shift of blood into the vessels of the chest, increasing the transmural filling pressure of the heart, and decreasing the central venous pressure. The increase in the transmural filling pressure of the heart is responsible, through a Starling-type mechanism, for the observed increases in heart size, left ventricular end-diastolic volume, stroke volume, and cardiac output.

scholarly journals Understanding basic vein physiology and venous blood pressure through simple physical assessments

2019 ◽  
Vol 43 (3) ◽  
pp. 423-429 ◽  
Author(s):  
Etain A. Tansey ◽  
Laura E. A. Montgomery ◽  
Joe G. Quinn ◽  
Sean M. Roe ◽  
Christopher D. Johnson
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Central Venous Pressure ◽  
Venous Return ◽  
Venous Pressure ◽  
Venous Blood ◽  
Venous System ◽  
Arterial System ◽  
Right Atrial ◽  
Central Venous

An understanding of the complexity of the cardiovascular system is incomplete without a knowledge of the venous system. It is important for students to understand that, in a closed system, like the circulatory system, changes to the venous side of the circulation have a knock-on effect on heart function and the arterial system and vice versa. Veins are capacitance vessels feeding blood to the right side of the heart. Changes in venous compliance have large effects on the volume of blood entering the heart and hence cardiac output by the Frank-Starling Law. In healthy steady-state conditions, venous return has to equal cardiac output, i.e., the heart cannot pump more blood than is delivered to it. A sound understanding of the venous system is essential in understanding how changes in cardiac output occur with changes in right atrial pressure or central venous pressure, and the effect these changes have on arterial blood pressure regulation. The aim of this paper is to detail simple hands-on physiological assessments that can be easily undertaken in the practical laboratory setting and that illustrate some key functions of veins. Specifically, we illustrate that venous valves prevent the backflow of blood, that venous blood pressure increases from the heart to the feet, that the skeletal muscle pump facilitates venous return, and we investigate the physiological and clinical significance of central venous pressure and how it may be assessed.

Central venous pressure in space

1996 ◽  
Vol 81 (1) ◽  
pp. 19-25 ◽  
Author(s):  
J. C. Buckey ◽  
F. A. Gaffney ◽  
L. D. Lane ◽  
B. D. Levine ◽  
D. E. Watenpaugh ◽  
...  
Keyword(s):  
Central Venous Pressure ◽  
Space Shuttle ◽  
Venous Pressure ◽  
Life Sciences ◽  
Left Ventricular ◽  
Filling Pressure ◽  
Fluid Distribution ◽  
Central Venous ◽  
Cardiac Filling Pressure ◽  
Cardiac Filling

Gravity affects cardiac filling pressure and intravascular fluid distribution significantly. A major central fluid shift occurs when all hydrostatic gradients are abolished on entry into microgravity (microG). Understanding the dynamics of this shift requires continuous monitoring of cardiac filling pressure; central venous pressure (CVP) measurement is the only feasible means of accomplishing this. We directly measured CVP in three subjects: one aboard the Spacelab Life Sciences-1 space shuttle flight and two aboard the Spacelab Life Sciences-2 space shuttle flight. Continuous CVP measurements, with a 4-Fr catheter, began 4 h before launch and continued into microG. Mean CVP was 8.4 cmH2O seated before flight, 15.0 cmH2O in the supine legs-elevated posture in the shuttle, and 2.5 cmH2O after 10 min in microG. Although CVP decreased, the left ventricular end-diastolic dimension measured by echocardiography increased from a mean of 4.60 cm supine preflight to 4.97 cm within 48 h in microG. These data are consistent with increased cardiac filling early in microG despite a fall in CVP, suggesting that the relationship between CVP and actual transmural left ventricular filling pressure is altered in microG.

scholarly journals Venous Function and Central Venous Pressure

2008 ◽  
Vol 108 (4) ◽  
pp. 735-748 ◽  
Author(s):  
Simon Gelman ◽  
David S. Warner ◽  
Mark A. Warner
Keyword(s):  
Central Venous Pressure ◽  
Blood Volume ◽  
Venous Return ◽  
Venous Pressure ◽  
Compartment Model ◽  
Total Blood Volume ◽  
Central Venous ◽  
Total Blood ◽  
Two Compartment Model ◽  
Venous Function

The veins contain approximately 70% of total blood volume and are 30 times more compliant than arteries; therefore, changes in blood volume within the veins are associated with relatively small changes in venous pressure. The terms venous capacity, compliance, and stressed and unstressed volumes are defined. Decreases in flow into a vein are associated with decreases in intravenous pressure and volume, and vice versa. Changes in resistance in the small arteries and arterioles may affect venous return in opposite directions; this is explained by a two-compartment model: compliant (mainly splanchnic veins) and noncompliant (nonsplanchnic veins). Effects of intrathoracic and intraabdominal pressures on venous return and central venous pressure as well as the value of central venous pressure as a diagnostic variable are discussed.

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