Achieving optimal pulmonary blood flow in the first-stage of palliation in early infancy for complex cardiac defects with hypoplastic left ventricles

1995 ◽  
Vol 5 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Tetsuya Kitagawa ◽  
Itsuo Katoh ◽  
Yoshiaki Fukumura ◽  
Masanori Yoshizumi ◽  
Yutaka Masuda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Arterial Oxygen Tension ◽  
Postoperative Mortality ◽  
Arterial Oxygen ◽  
Optimal Size ◽  
Mean Airway Pressure ◽  
Rigid Model ◽  
Pulmonary Arterial ◽  
Left Heart Syndrome

AbstractThe aim of the study was to determine the optimal size and technique for construction of the systemic-to-pulmonary arterial shunt which will provide suitable pulmonary blood flow in first-stage Norwood palliation for hypoplastic left heart syndrome in neonates. Our clinical experience suggested that an arterial oxygen tension of about 30 mm Hg immediately after cardiopulmonary bypass, with the patients being ventilated at the lowest possible mean airway pressure with an FiO2of 1.0, provided a suitable pulmonary-to-systemic flow ratio. We also aimed to clarify the characteristics of pulmonary blood flow in accordance with the size of the shunt and the change in the pulmonary vascular resistance in a simplified rigid model of the Norwood procedure. A hole of2.0 mm diameter proved adequate to provide a suitable pulmonary blood flow of 200−300 mlx002F;min in the presence of a pressure gradient of 20−40 mm Hg between the systemic and pulmonary circulations in neonates weighing 3 kg. A short central shunt with a prosthesis of4 mm in diameter produced an excessive flow of pulmonary blood. Our data suggest that using a smaller shunt than that commonly used is necessary to decrease the early and intermediate postoperative mortality. A prosthesis of 3.0 or 3.5 mm in diameter arising from the brachiocephalic artery would be acceptable and can be recommended for first-stage Norwood palliation in small infants, especially in view of the operative difficulties encountered in taking down the shunt at the time of subsequent operations.

Effect of continuous postive-pressure ventilation (CPPV) on edema formation in dog lung

1975 ◽  
Vol 39 (4) ◽  
pp. 672-679 ◽  
Author(s):  
P. Caldini ◽  
J. D. Leith ◽  
M. J. Brennan
Keyword(s):  
Blood Flow ◽  
Pulmonary Arterial Pressure ◽  
Venous Pressure ◽  
Arterial Oxygen Tension ◽  
Lung Parenchyma ◽  
Arterial Oxygen ◽  
Morphometric Measurements ◽  
Edema Formation ◽  
Significant Difference ◽  
Pulmonary Arterial

The effect of CPPV on edema formation in lungs perfused at constant blood flow was studied in whole dogs and in isolated dog lungs. In intact animals, subjected to an increase in left atrial pressure relative to pleural pressure of 40 Torr, pulmonary shunts correlate inversely (r = -0.82) with the level of end-expiratory pressure (PEE). CPPV had no significant effect on total extravasation of liquid even though PEE higher than 20 Torr was effective in preventing liquid from accumulating in the airways. In isolated lobes, perfused at constant blood flow and at a venous pressure of zero, accumulation of liquid occurred when PEE was increased above 8–10 Torr. At comparable levels of pulmonary arterial pressure, an increase in PEE resulted in lesser accumulation of liquid than when pulmonary venous pressure was elevated. Morphometric measurements revealed no significant difference in the distribution of accumulated liquid within the lung parenchyma between lobes made edematous either by raising venous pressuure or by raising PEE. It would appear that CPPV, while beneficial in improving arterial oxygen tension in pulmonary edema, does not prevent extravasation of liquid in lungs perfused at constant blood flow. High levels of PEE appear to damage the lung by favoring accumulation of liquid in the extravascular spaces of the lung.

scholarly journals Bidirectional Ductal Shunting and Preductal to Postductal Oxygenation Gradient in Persistent Pulmonary Hypertension of the Newborn

Children ◽  
2020 ◽  
Vol 7 (9) ◽  
pp. 137
Author(s):  
Amy Lesneski ◽  
Morgan Hardie ◽  
William Ferrier ◽  
Satyan Lakshminrusimha ◽  
Payam Vali
Keyword(s):  
Blood Flow ◽  
Pulmonary Hypertension ◽  
Pulmonary Blood Flow ◽  
Ductus Arteriosus ◽  
Arterial Oxygen Tension ◽  
Persistent Pulmonary Hypertension ◽  
Arterial Oxygen ◽  
Meconium Aspiration ◽  
Arterial Blood Gas ◽  
Arterial Blood

Background: The aim was to evaluate the relationship between the direction of the patent ductus arteriosus (PDA) shunt and the pre- and postductal gradient for arterial blood gas (ABG) parameters in a lamb model of meconium aspiration syndrome (MAS) with persistent pulmonary hypertension of the newborn (PPHN). Methods: PPHN was induced by intermittent umbilical cord occlusion and the aspiration of meconium through the tracheal tube. After delivery, 13 lambs were ventilated and simultaneous 129 pairs of pre- and postductal ABG were drawn (right carotid and umbilical artery, respectively) while recording the PDA and the carotid and pulmonary blood flow. Results: Meconium aspiration resulted in hypoxemia. The bidirectional ductal shunt had a lower postductal partial arterial oxygen tension ([PaO2] with lower PaO2/FiO2 ratio—97 ± 36 vs. 130 ± 65 mmHg) and left pulmonary flow (81 ± 52 vs. 133 ± 82 mL/kg/min). However, 56% of the samples with a bidirectional shunt had a pre- and postductal saturation gradient of < 3%. Conclusions: The presence of a bidirectional ductal shunt is associated with hypoxemia and low pulmonary blood flow. The absence of a pre- and postductal saturation difference is frequently observed with bidirectional right-to-left shunting through the PDA, and does not exclude a diagnosis of PPHN in this model.

Development of pulmonary vascular response to oxygen

1988 ◽  
Vol 254 (3) ◽  
pp. H542-H546 ◽  
Author(s):  
F. C. Morin ◽  
E. A. Egan ◽  
W. Ferguson ◽  
C. E. Lundgren
Keyword(s):  
Blood Flow ◽  
Right Ventricular ◽  
Oxygen Tension ◽  
Pulmonary Circulation ◽  
Pulmonary Blood Flow ◽  
Arterial Oxygen Tension ◽  
Arterial Oxygen ◽  
Absolute Pressure ◽  
Fetal Lamb ◽  
Near Term

The ability of the pulmonary circulation of the fetal lamb to respond to a rise in oxygen tension was studied from 94 to 146 days of gestation. The unanesthetized ewe breathed room air at normal atmospheric pressure, followed by 100% oxygen at three atmospheres absolute pressure in a hyperbaric chamber. In eleven near-term lambs (132 to 146 days of gestation), fetal arterial oxygen tension (PaO2) increased from 25 +/- 1 to 55 +/- 6 Torr (mean +/- SE), which increased the proportion of right ventricular output distributed to the fetal lungs from 8 +/- 1 to 59 +/- 5%. In five very immature lambs (94 to 101 days of gestation), fetal PaO2 increased from 27 +/- 1 to 174 +/- 70 Torr, but the proportion of right ventricular output distributed to the lung did not change, 8 +/- 1 to 9 +/- 1%. In five of the near-term lambs, pulmonary blood flow was measured. It increased from 34 +/- 3 to 298 +/- 35 ml.kg fetal wt-1.min-1, an 8.8-fold increase. We conclude that the pulmonary circulation of the fetal lamb does not respond to an increase in oxygen tension before 101 days of gestation; however, near term an increase in oxygen tension alone can induce the entire increase in pulmonary blood flow that normally occurs after the onset of breathing at birth.

Regional pulmonary blood flow during 96 hours of hypoxia in conscious sheep

1986 ◽  
Vol 61 (6) ◽  
pp. 2136-2143 ◽  
Author(s):  
D. C. Curran-Everett ◽  
K. McAndrews ◽  
J. A. Krasney
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Pulmonary Blood Flow ◽  
Pulmonary Arterial Pressure ◽  
Pressor Response ◽  
Superior Vena ◽  
Acute Hypoxia ◽  
Vena Cava ◽  
Normobaric Hypoxia ◽  
Pulmonary Arterial

The effects of acute hypoxia on regional pulmonary perfusion have been studied previously in anesthetized, artificially ventilated sheep (J. Appl. Physiol. 56: 338–342, 1984). That study indicated that a rise in pulmonary arterial pressure was associated with a shift of pulmonary blood flow toward dorsal (nondependent) areas of the lung. This study examined the relationship between the pulmonary arterial pressor response and regional pulmonary blood flow in five conscious, standing ewes during 96 h of normobaric hypoxia. The sheep were made hypoxic by N2 dilution in an environmental chamber [arterial O2 tension (PaO2) = 37–42 Torr, arterial CO2 tension (PaCO2) = 25–30 Torr]. Regional pulmonary blood flow was calculated by injecting 15-micron radiolabeled microspheres into the superior vena cava during normoxia and at 24-h intervals of hypoxia. Pulmonary arterial pressure increased from 12 Torr during normoxia to 19–22 Torr throughout hypoxia (alpha less than 0.049). Pulmonary blood flow, expressed as %QCO or ml X min-1 X g-1, did not shift among dorsal and ventral regions during hypoxia (alpha greater than 0.25); nor were there interlobar shifts of blood flow (alpha greater than 0.10). These data suggest that conscious, standing sheep do not demonstrate a shift in pulmonary blood flow during 96 h of normobaric hypoxia even though pulmonary arterial pressure rises 7–10 Torr. We question whether global hypoxic pulmonary vasoconstriction is, by itself, beneficial to the sheep.

The pulmonary vasculature in a neonatal porcine model with increased pulmonary blood flow and pressure

2001 ◽  
Vol 11 (4) ◽  
pp. 420-430 ◽  
Author(s):  
Elisabeth V. Stenbøg ◽  
Daniel A. Steinbrüchel ◽  
Anne Bloch Thomsen ◽  
Ulrik Baandrup ◽  
Lene Heickendorff ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Vascular Disease ◽  
Pulmonary Blood Flow ◽  
Left Pulmonary Artery ◽  
Pulmonary Vasculature ◽  
Pulmonary Vascular Disease ◽  
Systolic Pulmonary Arterial Pressure ◽  
Pulmonary Arterial ◽  
Circulating Levels

Introduction: Hypertension and hyperperfusion of the pulmonary vascular bed in the setting of congenital cardiac malformations may lead to progressive pulmonary vascular disease. To improve the understanding of the basic mechanisms of this disease, there is a need for clinically relevant animal models which reflect the disease process. Material and Results: We randomly allocated 45 newborn pigs, at the age of 48 hrs, to groups in which there was either construction of a 3 mm central aorto-pulmonary shunt, undertaken in 9, or ligation of the left pulmonary artery, achieved in 13. Controls included sham operations in 13, or no operations in 10 pigs. Follow-up was continued for three months. The interventions were compatible with survival in most pigs. The shunts resulted in an acute 85% increase in systolic pulmonary arterial pressure, and a more than twofold increase in pulmonary blood flow. By three months of age, nearly all shunts had closed spontaneously, and haemodynamics were normal. Ligation of the left pulmonary artery resulted in a normal total pulmonary blood flow, despite only the right lung being perfused, and a 33% increase in systolic pulmonary arterial pressure. These haemodynamic changes were maintained throughout the period of study. In both groups, histomorphometry revealed markedly increased muscularity of the intra-acinar pulmonary arteries. Circulating levels of endothelin were normal in the shunted animals, and elevated in those with ligation of the left pulmonary artery. Conclusion: In neonatal porcine models of pulmonary vascular disease, created by construction of 3 mm central aorto-pulmonary shunts and ligation of one pulmonary artery, we observed histopathological changes of the pulmonary vasculature similar to early hypertensive pulmonary vascular disease in humans. Elevated circulating levels of endothelin were associated with abnormal haemodynamics rather than abnormal pathology. These findings could be valuable for future studies on the pathogenesis of hypertensive pulmonary vascular disease associated with congenital cardiac malformations.

PULMONARY FUNCTION, DEDUCED FROM URINARY NITROGEN TENSIONS

PEDIATRICS ◽  
1967 ◽  
Vol 40 (6) ◽  
pp. 937-938
Author(s):  
M. E. A.
Keyword(s):  
Carbon Dioxide ◽  
Blood Flow ◽  
Pulmonary Function ◽  
Partial Pressure ◽  
Urine Sample ◽  
Pulmonary Blood Flow ◽  
Lung Perfusion ◽  
Alveolar Ventilation ◽  
Arterial Oxygen ◽  
Urinary Nitrogen

THE elegant studies reported by Led-better, Homma, and Farhi in this issue are entitled `'Readjustment in Distribution of Alveolar Ventilation and Lung Perfusion in the Newborn." It must come as a great surprise to the reader to discover that the only measurement actually made was the partial pressure of nitrogen in the infants' urine. How could one conclude that there were significant imbalances between the distribution of alveolar ventilation and pulmonary blood flow (VA/Q) in the first days of life in normal infants from a urine sample? It is all the more astounding in the light of previous (and seemingly more direct) studies of alveolar-arterial oxygen and carbon dioxide differences which led others to consider the differences largely explained by anatomical right-to-left shunts.

Effect of furosemide on pulmonary blood flow distribution in resting and exercising horses

1999 ◽  
Vol 86 (6) ◽  
pp. 2034-2043 ◽  
Author(s):  
Howard H. Erickson ◽  
Susan L. Bernard ◽  
Robb W. Glenny ◽  
M. Roger Fedde ◽  
Nayak L. Polissar ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Blood Flow ◽  
Flow Distribution ◽  
Thoroughbred Horses ◽  
Dorsal Portion ◽  
Primary Finding ◽  
Pulmonary Arterial ◽  
Relationship Of ◽  
The Relationship ◽  
Rest And Exercise

We determined the spatial distribution of pulmonary blood flow (PBF) with 15-μm fluorescent-labeled microspheres during rest and exercise in five Thoroughbred horses before and 4 h after furosemide administration (0.5 mg/kg iv). The primary finding of this study was that PBF redistribution occurred from rest to exercise, both with and without furosemide. However, there was less blood flow to the dorsal portion of the lung during exercise postfurosemide compared with prefurosemide. Furosemide did alter the resting perfusion distribution by increasing the flow to the ventral regions of the lung; however, that increase in flow was abated with exercise. Other findings included 1) unchanged gas exchange and cardiac output during rest and exercise after vs. before furosemide, 2) a decrease in pulmonary arterial pressure after furosemide, 3) an increase in the slope of the relationship of PBF vs. vertical height up the lung during exercise, both with and without furosemide, and 4) a decrease in blood flow to the dorsal region of the lung at rest after furosemide. Pulmonary perfusion variability within the lung may be a function of the anatomy of the pulmonary vessels that results in a predominantly fixed spatial pattern of flow distribution.

Heterogeneity of myocardial blood flow under normal conditions and its dependence on arterial PO2

1990 ◽  
Vol 258 (2) ◽  
pp. H549-H555 ◽  
Author(s):  
H. G. Wolpers ◽  
A. Hoeft ◽  
H. Korb ◽  
P. R. Lichtlen ◽  
G. Hellige
Keyword(s):  
Blood Flow ◽  
Myocardial Blood Flow ◽  
Coronary Blood Flow ◽  
Arterial Oxygen Tension ◽  
Inert Gases ◽  
Arterial Oxygen ◽  
Tracer Gas ◽  
Stochastic Description ◽  
Flow Reserve ◽  
Arterial Po2

We studied the heterogeneity of myocardial blood flow in nine anesthetized closed-chest dogs using an indicator-dilution technique that allows the stochastic description of transport characteristics for three inert gases (helium, argon, and xenon) from the coronary inflow to outflow. The results show that under normal conditions the transcoronary transport of the tracers is spatially heterogeneous. Heterogeneity is strongly dependent on the arterial oxygen tension over a range of 40–200 Torr. This could be similarly observed with each tracer gas despite different physicochemical properties and was largely independent from the magnitude of coronary blood flow. The results are interpreted to mean that the arteriolar or intratissue PO2 influences myocardial blood flow over a broad range and possibly acts as an important integrating factor in the local regulation of coronary blood flow and flow reserve.

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