Influence of lung volume and alveolar pressure on reverse pulmonary venous blood flow

1992 ◽  
Vol 73 (1) ◽  
pp. 195-199 ◽  
Author(s):  
T. Obermiller ◽  
S. Lakshminarayan ◽  
S. Willoughby ◽  
J. Mendenhall ◽  
J. Butler
Keyword(s):  
Lung Volume ◽  
Left Atrial ◽  
Venous Blood ◽  
Pulmonary Veins ◽  
Left Lung ◽  
Blood Gases ◽  
Venous Blood Flow ◽  
Alveolar Pressure ◽  
Artery Ligation ◽  
Venous Flow

We have reported that left atrial blood refluxes through the pulmonary veins to gas-exchanging tissue after pulmonary artery ligation. This reverse pulmonary venous flow (Qrpv) was observed only when lung volume was changed by ventilation. This was believed to drive Qrpv by alternately distending and compressing the alveolar and extra-alveolar vessels. Because lung and pulmonary vascular compliances change with lung volume, we studied the effect of positive end-expiratory pressure (PEEP) on the magnitude of Qrpv during constant-volume ventilation. In prone anesthetized goats (n = 8), using the right lung to maintain normal blood gases, we ligated the pulmonary and bronchial arterial inflow to the left lung and ventilated each lung separately. A solution of SF6, an inert gas, was infused into the left atrium. SF6 clearance from the left lung was determined by the Fick principle at 0, 5, 10, and 15 and again at 0 cmH2O PEEP and was used to measure Qrpv. Left atrial pressure remained nearly constant at 20 cmH2O because the increasing levels of PEEP were applied to the left lung only. Qrpv was three- to fourfold greater at 10 and 15 than at 0 cmH2O PEEP. At these higher levels of PEEP, there were greater excursions in alveolar pressure for the same ventilatory volume. We believe that larger excursions in transpulmonary pressure during tidal ventilation at higher levels of PEEP, which compressed alveolar vessels, resulted in the reflux of greater volumes of left atrial blood, through relatively noncompliant extra-alveolar veins into alveolar corner vessels, and more compliant extra-alveolar arteries.

Bronchial and reverse pulmonary venous blood flow protect the lung from ischemia-reperfusion injury

1994 ◽  
Vol 77 (2) ◽  
pp. 731-736 ◽  
Author(s):  
A. Hamvas ◽  
D. P. Schuster
Keyword(s):  
Blood Flow ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Venous Blood ◽  
Pulmonary Veins ◽  
Left Lung ◽  
Venous Blood Flow ◽  
Bronchial Circulation ◽  
Group I ◽  
Lung Deflation

We used an intact in vivo canine model of pulmonary ischemia-reperfusion injury to evaluate whether the bronchial circulation or reverse pulmonary venous blood flow would protect the lung from injury during 2 h of unilateral pulmonary arterial (PA) occlusion and lung deflation. Serial measurements of regional extravascular density and transcapillary protein flux were made after reperfusion by using the quantitative imaging technique of positron emission tomography. Twenty-one animals were divided into four experimental groups. In all experimental groups, the left PA was clamped and the left lung was allowed to collapse and remain unventilated for a period of 2 h. In addition, in group I (n = 5) the left bronchial circulation was disrupted and the left pulmonary veins were clamped, in group II (n = 5) the bronchial circulation and the pulmonary veins were left intact, in group III (n = 6) the bronchial circulation was left intact but the pulmonary veins were clamped, and in group IV (n = 5) the bronchial circulation was disrupted but the pulmonary veins remained patent. The rate of protein flux in the left lung was increased only in group I (complete ischemia with lung deflation) [mean 195 x 10(-4) min-1 (range 85–453 x 10(-4) min-1) at 0.25 h and 114 x 10(-4) min-1 (range 22–200 x 10(-4) min-1) at 3 h] after reventilation and PA reperfusion (normal = 49 +/- 31 x 10(-4) min-1). Extravascular density increased significantly from 0.25 to 3 h only in group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of lung volume and left atrial pressure on reverse pulmonary venous blood flow

1991 ◽  
Vol 70 (1) ◽  
pp. 447-453 ◽  
Author(s):  
T. Obermiller ◽  
S. Lakshminarayan ◽  
S. Willoughby ◽  
J. Mendenhall ◽  
J. Butler
Keyword(s):  
Lung Volume ◽  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Venous Blood Flow ◽  
Volume Changes ◽  
Venous Flow ◽  
Pressure Transients ◽  
Arterial Blood ◽  
Pulmonary Venous Flow

Infarction of the lung is uncommon even when both the pulmonary and the bronchial blood supplies are interrupted. We studied the possibility that a tidal reverse pulmonary venous flow is driven by the alternating distension and compression of alveolar and extra-alveolar vessels with the lung volume changes of breathing and also that a pulsatile reverse flow is caused by left atrial pressure transients. We infused SF6, a relatively insoluble inert gas, into the left atrium of anesthetized goats in which we had interrupted the left pulmonary artery and the bronchial circulation. SF6 was measured in the left lung exhalate as a reflection of the reverse pulmonary venous flow. No SF6 was exhaled when the pulmonary veins were occluded. SF6 was exhaled in increasing amounts as left atrial pressure, tidal volume, and ventilatory rates rose during mechanical ventilation. SF6 was not excreted when we increased left atrial pressure transients by causing mitral insufficiency in the absence of lung volume changes (continuous flow ventilation). Markers injected into the left atrial blood reached the alveolar capillaries. We conclude that reverse pulmonary venous flow is driven by tidal ventilation but not by left atrial pressure transients. It reaches the alveoli and could nourish the alveolar tissues when there is no inflow of arterial blood.

scholarly journals Effect of spontaneous breathing on umbilical venous blood flow and placental transfusion during delayed cord clamping in preterm lambs

2019 ◽  
Vol 105 (1) ◽  
pp. 26-32 ◽  
Author(s):  
Emma Brouwer ◽  
Arjan B te Pas ◽  
Graeme R Polglase ◽  
Erin V McGillick ◽  
Stefan Böhringer ◽  
...  
Keyword(s):  
Blood Flow ◽  
Body Weight ◽  
Spontaneous Breathing ◽  
Venous Blood ◽  
Vena Cava ◽  
Venous Blood Flow ◽  
Delayed Cord Clamping ◽  
Venous Flow ◽  
Cord Clamping ◽  
Pregnant Sheep

IntroductionDuring delayed umbilical cord clamping, the factors underpinning placental transfusion remain unknown. We hypothesised that reductions in thoracic pressure during inspiration would enhance placental transfusion in spontaneously breathing preterm lambs.ObjectiveInvestigate the effect of spontaneous breathing on umbilical venous flow and body weight in preterm lambs.MethodsPregnant sheep were instrumented at 132–133 days gestational age to measure fetal common umbilical venous, pulmonary and cerebral blood flows as well as arterial and intrapleural (IP) pressures. At delivery, doxapram and caffeine were administered to promote breathing. Lamb body weights were measured continuously and breathing was assessed by IP pressure changes.ResultsIn 6 lambs, 491 out of 1117 breaths were analysed for change in body weight. Weight increased in 46.6% and decreased in 47.5% of breaths. An overall mean increase of 0.02±2.5 g per breath was calculated, and no net placental transfusion was observed prior to cord clamping (median difference in body weight 52.3 [−54.9–166.1] g, p=0.418). Umbilical venous (UV) flow transiently decreased with each inspiration, and in some cases ceased, before UV flow normalised during expiration. The reduction in UV flow was positively correlated with the standardised reduction in (IP) pressure, increasing by 109 mL/min for every SD reduction in IP pressure. Thus, the reduction in UV flow was closely related to inspiratory depth.ConclusionsSpontaneous breathing had no net effect on body weight in preterm lambs at birth. UV blood flow decreased as inspiratory effort increased, possibly due to constriction of the inferior vena cava caused by diaphragmatic contraction, as previously observed in human fetuses.

Midline skull tumors

2015 ◽  
Vol 42 (S1) ◽  
pp. S44-S45
Author(s):  
M Maleki
Keyword(s):  
Rare Case ◽  
Venous Return ◽  
Venous Blood ◽  
Subtotal Resection ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Posterior Portion ◽  
Sagittal Sinus ◽  
Skull Tumors ◽  
Visual Blurring

Introduction: Variety of tumors could involve the skull; however, very few may occur over the midline. Some may affect venous blood flow of superior sagittal sinus. Few challenging cases are presented Material: 1-Rare case of osteoblastoma over the torcula, (headache, visual symptoms, papilledema, VI nerve palsy). 2- Rare case of metastatic liposarcoma involving midsagital sinus, partially occluding it (headache and visual blurring). 3- A huge atypical (grade2) meningioma over the vertex Method: Case #1, the tumor over the venous confluences (torcula) was removed easily, without any complications. Complete resolution of symptoms Case #2, complete en-block resection of tumor, with sacrifice of mid-sagittal portion of sinus, without any neurological sequellae. Case #3, subtotal resection, followed by radiotherapy.Discussion &Conclusion: Anterior 3rd of sagital sinus could be sacrificed (if necessary), without major consequences. However, whenever mid or posterior portion of the sinus is involved, interruption of venous flow could pose very serious complications. Occasionally, chronic compression of sinus may force increasing collateral venous return, in which case one may attempt a complete resection of the lesion, with sacrifice of part of the sinus, as in our second case. In the region of torcula, however, one should be very careful not to damage it

Phase-contrast MR assessment of pulmonary venous blood flow in children with surgically repaired pulmonary veins

2003 ◽  
Vol 33 (9) ◽  
pp. 607-613 ◽  
Author(s):  
Emanuela R. Valsangiacomo ◽  
Catherine Barrea ◽  
Christopher K. Macgowan ◽  
Jeffrey F. Smallhorn ◽  
John G. Coles ◽  
...  
Keyword(s):  
Blood Flow ◽  
Phase Contrast ◽  
Venous Blood ◽  
Pulmonary Veins ◽  
Venous Blood Flow

scholarly journals Impact of Multi-parametric Analyses on Normal Left Atrial Strain by Cardiovascular Magnetic Resonance Feature Tracking

2022 ◽  
Author(s):  
Jan Eckstein ◽  
Hermann Körperich ◽  
Lech Paluszkiewicz ◽  
Wolfgang Burchert ◽  
Misagh Piran
Keyword(s):  
Gender Differences ◽  
Heart Rate ◽  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Left Atrial ◽  
Feature Tracking ◽  
Venous Blood ◽  
Left Ventricular ◽  
Venous Blood Flow ◽  
Left Atrial Strain

Abstract Left-atrial (LA) strain is the result of complex hemodynamics, increasingly assessed by feature-tracking cardiovascular magnetic resonance (CMR). We investigate the value of multi-parametric regression (MPR) analyses and the influence of the heart rate on LA-strain. As LA-strain data remains limited, CMR-quantified sex- and age-dependent normal values were derived. After following a health assessment questionnaire, 183 healthy volunteers (11-70 years, 97 females, median 32.9±28.3 years) were recruited for LA-strain assessment. LA volumetric data, left ventricular strain, transmitral and pulmonary venous blood flow parameters were utilized to create clusters for MPR analyses for all subjects and heart rate-specific subgroups (range: 60–75 beats-per-minute, N=106). In comparison to the total cohort, subgroups showed no gender differences (p>0.05) for LA reservoir, conduit and booster strains (all: 47.3±12.7%; 29.0±15.5%; 17.6±5.4%) and strain rates (all: 2.1±1.0 s−1; -2.9 ± 1.5 s−1; -2.3 ± 1.0 s−1). MPR analyses identified parameter clusters with large effect size (|R²|≥0.26) for reservoir-, conduit- and booster strain and corresponding active and passive cardiac functional parameters. Increased correlations for the subgroup were found. In contrast to previous studies, heart rate selected subgroups showed no gender differences in LA-strain. MPR analyses improve characterization of LA-strain at selected heart rates.

Assessment Of Venous Function After Major Gynecological Surgery With Heparin-Dihydroergotamine In The Prophylaxis Of DVT

1981 ◽  
Author(s):  
S Kunz ◽  
O M Burth ◽  
E Zimmerer
Keyword(s):  
Doppler Ultrasonography ◽  
Varicose Veins ◽  
Synergistic Effects ◽  
Venous Blood ◽  
Haemodynamic Effect ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Venous Function ◽  
The Right ◽  
Clinical Conditions

Dihydroergotamine (DHE) has been shown to have synergistic effects with heparin in the prophylaxis of DVT. To assess the hemodynamic efficacy of DHE in clinical conditions, 72 patients undergoing hysterectomy were randomly allocated to three groups receiving heparin/DHE, heparin or acenocoumarol. Venous function was measured by occlusion plethysmography and doppler ultrasonography. Diagnosis of DVT by 125-I-fibrinogen test.Results: Doppler Ultrasonography: The velocity of venous flow in the left V. femoralis was lower than at the right side in all groups before hysterectomy. After surgery, a significant increase from 11.2 to 15.5 cm/sec in the heparin/DHE group could be demonstrated. Heparin and acenocoumarol patients showed a tendency to lower venous return. The differences were more marked in women with vaginal hysterectomy.Occlusion plethysmography: No differences in venous capacity before and after operation could be found in the heparin and acenocoumarol group. A significant reduction (16%) was measured in heparin/DHE treated patients. The maximal venous outflow also was significantly reduced in this group (18%). This difference also was found in patients with varicose veins.Conclusions: The data confirm that DHE increases the velocity of venous blood flow in the legs by constricting the capacitance vessels. This haemodynamic effect could be demonstrated in clinical conditions.

Do we still need compression bandages? Haemodynamic effects of compression stockings and bandages

2006 ◽  
Vol 21 (3) ◽  
pp. 132-138 ◽  
Author(s):  
H Partsch
Keyword(s):  
Flow Velocity ◽  
Venous Blood ◽  
Haemodynamic Effects ◽  
Venous Blood Flow ◽  
Compression Stockings ◽  
Venous Flow ◽  
Elastic Compression ◽  
Compression Bandages ◽  
Interface Pressures ◽  
Pumping Function

Objective: To compare haemodynamic data obtained with elastic compression stockings and inelastic compression material applied with different pressure ranges on the lower extremities. Methods: Haemodynamic effects of compression therapy were demonstrated by measuring venous flow velocity, venous volume, venous reflux and venous pumping function using radioisotopes, phlebography, water displacement volumetry, duplex, air plethysmography, foot volumetry and phlebodynamometry. Results: Light-compression stockings are able to increase venous blood flow velocity in the supine position and to prevent leg swelling after prolonged sitting and standing. In the upright position an interface pressure of more than 50 mmHg is needed for an intermittent occlusion of incompetent veins and for a reduction of ambulatory venous hypertension during walking. Such high interface pressures may rather be achieved by short-stretch, multilayer bandages than by an elastic stocking. Conclusion: Elastic compression stockings exerting interface pressures up to 40 mmHg are effective in preventing or reducing oedema. Multilayer compression bandages with a pressure over 40 mmHg additionally improve severely disturbed venous pumping function.

scholarly journals КОМПРЕСІЙНА АСФІКСІЯ

2019 ◽  
Vol 1 (11(41)) ◽  
pp. 26-31
Author(s):  
Хоботова Наталія Володимирівна ◽  
Єхалов Василій Вталійович
Keyword(s):  
Venous Blood ◽  
Intrathoracic Pressure ◽  
Shoulder Girdle ◽  
External Pressure ◽  
The Body ◽  
Whole Body ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Septic Complications ◽  
The Face

Compression asphyxia is a type of mechanical asphyxia when breathing stops with external pressure on the body, which leads to the absence of respiratory movements and disrupts venous return from the head. With a strong compression of the chest, a reflex spasm of the glottis occurs, which contributes to an increase in intrathoracic pressure, reverse venous blood flow and an obstruction of venous flow to the heart occur. A sharp increase in intracranial pressure and venous congestive congestion / hemorrhage deepen central respiratory failure. Mild degree: mental agitation; puffy face, slight cyanosis; individual conjunctival petechiae; tachypnea. Medium degree: light or heavy stunning, lost orientation; the face is puffy, cyanotic; swelling of the cervical veins, acrocyanosis; multiple petechiae that spread across the face, neck, conjunctiva of the eyes, inspiratory dyspnea, visual impairment. Severe degree: stupor or coma, sharp cyanosis of the whole body, exophthalmos; swelling of the face, neck and shoulder girdle, arms, multiple petechiae of the face, neck, arms, legs, conjunctiva of the eyes, swelling of the cervical veins, cyanosis and edema of the upper half of the body; superficial breathing, frequent, in the absence of treatment passes to agonal and apnea. Intensive care includes analgesia, oxygenation or mechanical ventilation, anticonvulsant, dehydration and decongestant therapy, prevention of acute kidney damage, DIC, septic complications, and treatment of posthypoxic encephalopathy.

scholarly journals Arterio-Venous Branchial Blood Flow in the Atlantic Cod Gadus Morhua

1992 ◽  
Vol 165 (1) ◽  
pp. 73-84 ◽  
Author(s):  
LENA SUNDIN ◽  
STEFAN NILSSON
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Atlantic Cod ◽  
Vascular System ◽  
Venous Blood ◽  
Venous Blood Flow ◽  
Venous Flow ◽  
Flow Measurements ◽  
Vasomotor Function

We have estimated the branchial venous blood flow in the Atlantic cod by direct single-crystal Doppler blood flow measurements in vivo. In the undisturbed animal, this flow amounts to 1.7 ml min−1 kg−1, which corresponds to about 8 % of the cardiac output. Studies of both an isolated perfused gill apparatus in situ and simultaneous measurements of cardiac output and branchial venous flow in vivo were made to assess the effects of some putative vasoregulatory substances. Adrenaline dilates the arterio-arterial pathway and constricts the arterio-venous pathway, thus decreasing branchial venous drainage. 5-Hydroxytryptamine (5-HT), in contrast, produced marked vasoconstriction in the arterio-arterial pathway of the branchial vasculature, increasing the branchial venous blood flow. Cholecystokinin-8 (CCK-8) and caerulein produced similar cardiovascular effects, with marked constriction of both arterio-arterial and arterio-venous pathways. The study demonstrates the ability of the vascular system of the gills to regulate the distribution of branchial blood flow, and summarizes the vasomotor effects of some substances with possible vasomotor function in the cod gills.

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