A method for analysis of pulmonary arterial and venous occlusion data

1992 ◽  
Vol 73 (3) ◽  
pp. 1190-1195 ◽  
Author(s):  
S. H. Audi ◽  
C. A. Dawson ◽  
J. H. Linehan
Keyword(s):  
Compartmental Model ◽  
Venous Occlusion ◽  
Time Data ◽  
Equilibrium Pressure ◽  
New Approach ◽  
Lung Lobe ◽  
C Distribution ◽  
Average Slope ◽  
Arterial Inflow ◽  
Pulmonary Arterial

Recently, we presented a compartmental model of the pulmonary vascular resistance (R) and compliance (C) distribution with the configuration C1R1C2R2C3 (J. Appl. Physiol. 70: 2126–2136, 1991). This model was used to interpret the pressure vs. time data obtained after the sudden occlusion of the arterial inflow (AO), venous outflow (VO), or both inflow and outflow (DO) from an isolated dog lung lobe. In the present study, we present a new approach to the data analysis in terms of this model that is relatively simple to carry out and more robust. The data used to estimate the R′s and C′s are the steady-state arterial [Pa(0)] and venous [Pv(0)] pressures, the flow rate (Q), the area (A2) encompassed by Pa(t) after AO and the equilibrium pressure (Pd) after DO, and the average slope (m) of the Pa(t) and Pv(t) curves after VO. The following formulas can then be used to calculate the 2 R′s and 3 C′s: [Pa(0) - Pv(0)]/Q = R1 + R2 = RT, R1C1 congruent to to A2/[Pa(0) - Pd], R1 congruent to [Pa(0) - Pd]/Q, Q/m = C1 + C2 + C3 = CT, and C2 = CT - (RTC1/R2).

Modulation of vascular reactivity to serotonin in the dog lung

1991 ◽  
Vol 71 (1) ◽  
pp. 217-222 ◽  
Author(s):  
W. F. Hofman ◽  
W. F. Jackson ◽  
H. el-Kashef ◽  
I. C. Ehrhart
Keyword(s):  
Arterial Pressure ◽  
Vascular Reactivity ◽  
Pulmonary Arterial Pressure ◽  
Pressor Response ◽  
Venous Occlusion ◽  
Lung Lobe ◽  
Lower Lung ◽  
Pulmonary Arterial ◽  
Pressure Changes ◽  
Related Increase

Experiments were conducted to compare the effects of cyclooxygenase inhibition (COI) on vascular reactivity to serotonin (5-HT) in the isolated blood-perfused canine left lower lung lobe (LLL) and in isolated canine intrapulmonary lobar artery rings with and without a functional endothelium. LLLs (n = 6), perfused at constant blood flow, were challenged with bolus doses of 50, 100, and 250 micrograms 5-HT before COI, after COI with 45 microM meclofenamate, and after infusion of prostacyclin (PGI2) during COI. Lobar vascular resistance was segmentally partitioned by venous occlusion. Pulmonary arterial pressure increased from 13.5 +/- 1.0 to 16.3 +/- 0.8 cmH2O (P less than 0.01) after COI but declined to 13.1 +/- 1.1 cmH2O (P less than 0.01) subsequent to PGI2 infusion (91.3 +/- 14.5 ng.min-1.g LLL-1). The pulmonary arterial pressure changes were related to changes in postcapillary resistance. The dose-dependent pressor response to 5-HT was potentiated by COI (P less than 0.01) but reversibly attenuated (P less than 0.05) by PGI2 infusion. Isolated intrapulmonary artery rings (2–4 mm diam) exhibited a dose-related increase in contractile tension to 5-HT. The response to 5-HT was enhanced (P less than 0.05) in rings devoid of a functional endothelium. However, COI (10 microM indomethacin) did not alter (P greater than 0.05) the dose-related increase in contractile tension to 5-HT in rings with an intact endothelium. Our results suggest that both PGI2 and endothelium-derived relaxing factors modulate pulmonary vascular reactivity to 5-HT.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of vascular resistance and compliance in a dog lung lobe

1982 ◽  
Vol 53 (1) ◽  
pp. 158-168 ◽  
Author(s):  
J. H. Linehan ◽  
C. A. Dawson ◽  
D. A. Rickaby
Keyword(s):  
Vascular Resistance ◽  
Close Agreement ◽  
Central Compartment ◽  
Pressure Data ◽  
Venous Outflow ◽  
Equilibrium Pressure ◽  
Lung Lobe ◽  
Vascular Compliance ◽  
Arterial Inflow ◽  
Capillary Bed

We have modeled the left lower dog lung lobe as three serial compartments, each containing resistance (R) and compliance (C). The intracompartmental arrangement of R and C was chosen to permit their evaluation from pressure data obtained following occlusion of the venous outflow. We found that two mathematically distinct models permitted evaluation of the distribution of R and C. The models were complementary in that when used together the R and C of the three compartments could be determined. The central compartment had 46% of the lobar vascular resistance and 75% of the lobar vascular compliance under control conditions. We found that serotonin and histamine, which increased the resistance proximal and distal to the central compartment, respectively, did not increase the central resistance. Therefore, we conclude that the central compartment includes the capillary bed. The equilibrium pressure (Pd), obtained when arterial inflow and venous outflow were simultaneously occluded, was in close agreement with the average preocclusion pressure of the central compartment, indicating that Pd is close to the pulmonary microvascular pressure.

Effects of cyclooxygenase inhibition on pulmonary vascular responses to serotonin

1987 ◽  
Vol 62 (3) ◽  
pp. 1192-1200 ◽  
Author(s):  
W. F. Hofman ◽  
I. C. Ehrhart
Keyword(s):  
Blood Volume ◽  
Left Lung ◽  
Venous Occlusion ◽  
Cyclooxygenase Inhibitors ◽  
Cyclooxygenase Inhibition ◽  
Fourfold Increase ◽  
Lung Lobe ◽  
Before And After ◽  
Pulmonary Arterial ◽  
Dose Dependent

The vasopressor response to graded bolus doses (50–500 micrograms) of serotonin (5-hydroxytryptamine; 5-HT) was examined in the isolated canine lower left lung lobe (LLL) perfused at constant flow with autogenous blood before and after cyclooxygenase inhibition (COI). Lobar vascular resistance (LVR) was partitioned into pre- (Ra) and postcapillary (Rv) segments by venous occlusion with lobar blood volume changes monitored gravimetrically. Before COI, 5-HT produced transient, dose-dependent increases in pulmonary arterial pressure (Ppa) of 43.8 +/- 4.8–123.0 +/- 8.5% (n = 22) and simultaneous decreases in lobar blood volume (5.5 +/- 0.5–8.2 +/- 0.6 g/100 g LLL) with nearly proportionate increases in Ra and Rv at each 5-HT dose. After the initial challenge to 5-HT, LLL's were treated either with saline (n = 7) or one of three chemically distinct cyclooxygenase inhibitors. COI with 40 microM indomethacin (n = 6) or 45 microM meclofenamate (n = 6) increased resting LVR by 36.0 +/- 8.3% (P less than 0.01; n = 12) and decreased the Ra/Rv from 1.9 +/- 0.3 to 1.1 +/- 0.2 (P less than 0.01), whereas 1 mM aspirin (n = 3) caused a fourfold increase in resting LVR without affecting Ra/Rv. After indomethacin or meclofenamate treatment, the vasopressor response to graded doses of 5-HT was markedly potentiated as Ppa increased by 71.6 +/- 7.6–207.0 +/- 24.6%. COI did not potentiate the lobar vasopressor response to graded doses (10–100 micrograms) of norepinephrine (NE, n = 6).(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals New approach for localization and smart data transmission inside underground mine environment

2021 ◽  
Vol 3 (6) ◽  
Author(s):  
Ankita RayChowdhury ◽  
Ankita Pramanik ◽  
Gopal Chandra Roy
Keyword(s):  
Data Transmission ◽  
Signal To Noise Ratio ◽  
Visible Light Communication ◽  
Underground Mine ◽  
Control Room ◽  
Time Data ◽  
New Approach ◽  
Mine Environment ◽  
Surface Control ◽  
Smart Data

AbstractThis paper presents an approach to access real time data from underground mine. Two advance technologies are presented that can improve the adverse environmental effect of underground mine. Visible light communication (VLC) technology is incorporated to estimate the location of miners inside the mine. The distribution of signal to noise ratio (SNR) for VLC system is also studied. In the second part of the paper, long range (LoRa) technology is introduced for transmitting underground information to above the surface control room. This paper also includes details of the LoRa technology, and presents comparison of ranges with existing above the surface technologies.

scholarly journals Pulmonary venous occlusion and death in pulmonary arterial hypertension: survival analyses using radiographic surrogates

2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasuko Takeda ◽  
Yutaka Takeda ◽  
Koji Yamamoto ◽  
Shigehiro Tomimoto ◽  
Tomomitsu Tani ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Venous Occlusion ◽  
Survival Analyses ◽  
Pulmonary Arterial

Venous Occlusion Plethysmography in Patients with Cold Related Symptoms after Digital Salvage Procedures

1985 ◽  
Vol 10 (2) ◽  
pp. 151-154
Author(s):  
SIMON KAY
Keyword(s):  
Venous Occlusion ◽  
Venous Occlusion Plethysmography ◽  
Nerve Function ◽  
Cold Intolerance ◽  
Arterial Inflow

Fourteen patients who had undergone microsurgical salvage of one or more digits were interviewed and examined. An assessment of sensitivity to cold is defined as cold intolerance and correlated with nerve function and arterial inflow measured by venous occlusion plethysmography. No relationship between arterial inflow and cold intolerance nor nerve function was found. There was, however a tendency for worsening cold intolerance to be associated with poorer nerve function. Half the salvaged digits had arterial inflow greater than the contralateral control digit.

Vascular reactivity and permeability to serotonin in cyclooxygenase-inhibited dog lung

1988 ◽  
Vol 255 (5) ◽  
pp. H1096-H1105
Author(s):  
W. F. Hofman ◽  
I. C. Ehrhart
Keyword(s):  
Vascular Reactivity ◽  
Pressor Response ◽  
Left Lung ◽  
Base Line ◽  
Fluid Filtration ◽  
Lung Lobe ◽  
Pressor Responses ◽  
Pulmonary Arterial ◽  
Group 5 ◽  
Dose Dependent Increase

We examined the effects of serotonin (5-HT) infusion on hemodynamics, vascular compliance (Cvasc), and the filtration coefficient (Kf) in the isolated canine lower left lung lobe (LLL) perfused at constant flow. In one group (5-HT; n = 8), 5-HT was infused at 55 micrograms/min for 35 min and then at 105 micrograms/min for 15 min before and during a Kf determination. Cyclooxygenase inhibition (COI) was induced by 40 microM indomethacin (n = 4) or 45 microM meclofenamate (n = 4) before 5-HT infusion in a second group (5-HTCOI; n = 8). Control LLLs (n = 8) were given equivalent volumes of saline. The pulmonary arterial pressure (Pa) increase to 55 micrograms/min 5-HT (3.0 +/- 0.6 Torr; 43.7%) was nearly doubled (P less than 0.01) with COI (10.5 +/- 1.5 Torr; 83.3%), while LLL weight decreased 6.2 g/100 g in both groups. With 5-HT infusion, the dose-dependent increase in Pa, lobar vascular resistance, and precapillary resistance was greater (P less than 0.05) in the 5-HTCOI than the 5-HT group, but capillary pressure (Pc) was not increased from base-line values. Kf values did not differ (P greater than 0.05) among groups but Cvasc was reduced (P less than 0.05) in the 5-HTCOI group. We found that 5-HT increases Pa, but does not appear to promote microvessel fluid filtration by increasing Pc or the Kf. The enhanced and sustained pressor response to 5-HT with COI suggests that vasodilatory prostaglandins may modulate pressor responses to 5-HT.

Phasic capillary pressure determined by arterial occlusion in intact dog lung lobes

1989 ◽  
Vol 67 (6) ◽  
pp. 2205-2211 ◽  
Author(s):  
Y. Yamada ◽  
M. Suzukawa ◽  
M. Chinzei ◽  
T. Chinzei ◽  
N. Kawahara ◽  
...  
Keyword(s):  
Capillary Pressure ◽  
Vascular Resistance ◽  
Control Period ◽  
Arterial Occlusion ◽  
Lung Lobe ◽  
Pulmonary Capillary ◽  
Pulmonary Capillary Pressure ◽  
Lower Lung ◽  
Pulmonary Arterial ◽  
Electrocardiogram Ecg

In six open-chest dogs, electrocardiogram- (ECG) controlled pulmonary arterial occlusion was performed during the control period and during the infusions of serotonin and histamine. A temporal series of instantaneous pulmonary capillary pressure and the longitudinal distributions of vascular resistance and compliance were evaluated in the intact left lower lung lobe. In the control period, we found a significant phasic variation of pulmonary capillary pressure (Pc) with the cardiac cycle. The ratio of arterial to venous resistances (Ra/Rv) was 6:4, and the ratio of arterial to capillary compliances (Ca/Cc) was 1:11. During the infusions of serotonin and histamine, Pc showed similar phasic variations, despite significant hemodynamic changes induced by these agents. Serotonin predominantly increased Ra, whereas histamine predominantly increased Rv. The ratio of Rv to the total resistance decreased significantly from 0.42 to 0.32 during the infusion of serotonin and increased significantly to 0.62 during the infusion of histamine. The data suggest that phasic Pc determined by ECG-controlled arterial occlusion reflects the pulsatility in the pulmonary microvascular bed under control conditions and after alterations of the pulmonary vascular resistance by serotonin and histamine.

A three-compartment model of the pulmonary vasculature: effects of vasoconstriction

1983 ◽  
Vol 55 (3) ◽  
pp. 923-928 ◽  
Author(s):  
J. H. Linehan ◽  
C. A. Dawson
Keyword(s):  
Pressure Drop ◽  
Fluid Pressure ◽  
Compartment Model ◽  
Venous Occlusion ◽  
Pulmonary Vasculature ◽  
Lung Lobe ◽  
Prostaglandin F2 Alpha ◽  
Vascular Bed ◽  
Middle Compartment ◽  
The Impact

The venous occlusion experiments provide sufficient data to permit the vascular bed of a dog lung lobe to be mathematically modeled as three serial compartments, each containing a quantifiable resistance separated by equal parallel compliances. To determine how these compartments are related to the sites of vasomotion in the pulmonary vascular bed we investigated the effects of various pulmonary vasomotor stimuli. We found that serotonin, sympathetic nerve stimulation, hypoxia, and prostaglandin F2 alpha increased the pressure drop upstream (arterial) from the site of major lobar compliance. On the other hand, histamine, norepinephrine, epinephrine, and elevation of the cerebrospinal fluid pressure increased the pressure drop downstream (venous) from the site of major lobar compliance. These stimuli either did not affect the pressure drop across the middle compartment or increased it slightly. Thus we conclude that the middle compartment represents vessels located between the muscular arteries and veins including the capillary bed and possibly other small nonmuscular vessels. Further, the average preocclusion pressure in the middle compartment is a microvascular pressure that can be used to evaluate the impact of vasoconstriction on the lobar microcirculation.

Functional diameters of alveolar microvessels at high lung volume in zone II

1998 ◽  
Vol 85 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Robert L. Conhaim ◽  
Lance A. Rodenkirch
Keyword(s):  
Flow Cytometry ◽  
Confocal Microscopy ◽  
Lung Volume ◽  
Left Atrial ◽  
Venous Outflow ◽  
Latex Particles ◽  
Arterial Inflow ◽  
Pulmonary Arterial ◽  
Zone Ii ◽  
Isolated Rat

To estimate the functional diameter of alveolar microvessels, we perfused isolated rat lungs with fluorescent latex particles (1 diameter/lung) at inflation, pulmonary arterial, and left atrial pressures of 25, 30, and 0 cmH2O, respectively. We used confocal microscopy to count latex particles within septal microvessels and flow cytometry to count particle concentrations in venous outflow. We found 1-, 2-, and 4-μm-diameter particles within septal vessels of 45 ± 12, 31 ± 12, and 25 ± 9%, respectively, of examined alveoli. Particles of 5-μm diameter were absent from septal vessels but were present within a small percentage of corner vessels. Particle concentrations in the venous outflow for 1-, 2-, 4-, and 5-μm-diameter particles were 54 ± 28, 67 ± 32, 2.2 ± 0.3, and 0.4 ± 0.3%, respectively, of the arterial inflow. Particles with diameters of 6 or 10 μm were absent from venous outflow. Our results suggest that, under these conditions, the functional diameter of the septal microvessels is ∼4 μm and that the diameter of the adjacent corner vessels is slightly larger but <6 μm.

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