scholarly journals An investigation to show the effect of lung fluid on impedance cardiac output in the anaesthetized dog

2005 ◽  
Vol 95 (4) ◽  
pp. 458-464 ◽  
Author(s):  
Z.-Y. Peng ◽  
L.A.H. Critchley ◽  
B.S.P. Fok
Keyword(s):  
Cardiac Output ◽  
Lung Fluid ◽  
Anaesthetized Dog

Effects of arginine vasopressin on hemodynamics and lung fluid balance in lambs

1989 ◽  
Vol 256 (3) ◽  
pp. H641-H647 ◽  
Author(s):  
A. L. Gest ◽  
A. A. Moise ◽  
T. N. Hansen ◽  
S. Kaplan
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Fluid Balance ◽  
Arginine Vasopressin ◽  
Left Atrial ◽  
Plasma Concentrations ◽  
Base Line ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Lung Lymph

The purpose of this project was to study the effects of increased plasma concentrations of arginine vasopressin (AVP) on hemodynamics and lung fluid balance in lambs. We studied 16 unanesthetized newborn lambs during a base-line period and while infusing AVP into a hindlimb vein at 1.65 +/- 0.12 and 2.98 +/- 0.15 mU.kg-1.min-1. We measured aortic, pulmonary arterial, and left atrial pressures and heart rate continuously and cardiac output at frequent intervals. In five additional experiments, we collected samples of pure lung lymph during a base-line period and while infusing AVP at 2.02 +/- 0.15 mU.kg-1.min-1. AVP infusion increased plasma concentrations of AVP to 11.3 +/- 5.2 and 19.9 +/- 5.2 microU/ml at the low and high rates of infusion, respectively. Both aortic and left atrial pressures increased at the low rate of infusion (11 and 3 Torr, respectively) but remained unchanged at the higher rate. Systemic vascular resistance increased, and heart rate and cardiac output decreased at each rate of infusion. In fact, at the higher rate of infusion cardiac output decreased 38% when compared with base line. Neither pulmonary artery pressure nor pulmonary vascular resistance was affected by infusion of AVP. Despite the increase in left atrial pressure, the rate of lung lymph flow was not affected by the infusion of AVP, whereas the lymph-to-plasma protein ratio decreased slightly but significantly from 0.64 +/- 0.02 to 0.60 +/- 0.02.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of progressive exercise on lung fluid balance in sheep

1988 ◽  
Vol 64 (5) ◽  
pp. 2125-2131 ◽  
Author(s):  
J. H. Newman ◽  
B. J. Butka ◽  
R. E. Parker ◽  
R. J. Roselli
Keyword(s):  
Cardiac Output ◽  
Fluid Balance ◽  
Lymph Flow ◽  
Base Line ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Progressive Exercise ◽  
Pulmonary Arterial ◽  
Lung Lymph ◽  
Lung Lymph Flow

The purpose of this study is to determine the roles of cardiac output and microvascular pressure on changes in lung fluid balance during exercise in awake sheep. We studied seven sheep during progressive treadmill exercise to exhaustion (10% grade), six sheep during prolonged constant-rate exercise for 45–60 min, and five sheep during hypoxia (fraction of inspired O2 = 0.12) and hypoxic exercise. We made continuous measurements of pulmonary arterial, left atrial, and systemic arterial pressures, lung lymph flow, and cardiac output. Exercise more than doubled cardiac output and increased pulmonary arterial pressures from 19.2 +/- 1 to 34.8 +/- 3.5 (SE) cmH2O. Lung lymph flow increased rapidly fivefold during progressive exercise and returned immediately to base-line levels when exercise was stopped. Lymph-to-plasma protein concentration ratios decreased slightly but steadily. Lymph flows correlated closely with changes in cardiac output and with calculated microvascular pressures. The drop in lymph-to-plasma protein ratio during exercise suggests that microvascular pressure rises during exercise, perhaps due to increased pulmonary venous pressure. Lymph flow and protein content were unaffected by hypoxia, and hypoxia did not alter the lymph changes seen during normoxic exercise. Lung lymph flow did not immediately return to base line after prolonged exercise, suggesting hydration of the lung interstitium.

The effect of lung injury and excessive lung fluid, on impedance cardiac output measurements, in the critically ill

2000 ◽  
Vol 26 (6) ◽  
pp. 679-685 ◽  
Author(s):  
L. A.H. Critchley ◽  
R. M. Calcroft ◽  
P. Y. H. Tan ◽  
J. Kew ◽  
J. A.J. H. Critchley
Keyword(s):  
Cardiac Output ◽  
Lung Injury ◽  
Critically Ill ◽  
Lung Fluid ◽  
Cardiac Output Measurements

Effect of pulmonary perfusion on lung fluid filtration in young lambs

1988 ◽  
Vol 255 (6) ◽  
pp. H1336-H1341 ◽  
Author(s):  
W. G. Teague ◽  
M. E. Berner ◽  
R. D. Bland
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Surface Area ◽  
Left Atrial ◽  
Pulmonary Blood Flow ◽  
Balloon Catheter ◽  
Lymph Flow ◽  
Pulmonary Perfusion ◽  
Fluid Filtration ◽  
Lung Fluid

To study the effect of pulmonary perfusion on fluid filtration in the newborn lung, we measured pulmonary vascular pressures, cardiac output, lung lymph flow, and concentrations of protein in lymph and plasma of nine healthy, awake lambs, 2–3 wk old, before and during sustained alterations in pulmonary blood flow. A 12% reduction in cardiac output (from partial occlusion of the inferior vena cava) led to a corresponding decrease in lymph flow, consistent with a reduction in net lung fluid filtration. A 20% increase in pulmonary blood flow (from opening an external shunt between the carotid artery and jugular vein) increased lymph flow by approximately 40%, without a significant change in lymph protein concentration. These findings suggest that lung microvascular surface area expanded in response to increased perfusion, with little or no change in filtration pressure. In five lambs, lung microvascular pressure was increased by inflating a balloon catheter in the left atrium to establish full patency of the pulmonary microcirculation. In the presence of left atrial pressure elevation, increased perfusion through the arteriovenous shunt had no significant effect on pulmonary vascular pressures or lymph flow. Thus, in young lambs, modest changes in pulmonary blood flow may affect lung fluid filtration by altering perfused microvascular surface area; this response is inhibited in the presence of left atrial hypertension.

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