Unilateral lung edema: effects on pulmonary gas exchange, hemodynamics, and pulmonary perfusion distribution

Two types of unilateral lung edema in sheep were characterized regarding their effects on pulmonary gas exchange, hemodynamics, and distribution of pulmonary perfusion. One edema type was induced with aerosolized HCl (0.15 M, pH 1.0) and the other with NaCl (0.15 M, pH 7.4). Both aerosols were nebulized continuously for 4 h into left lungs. In HCl-treated animals, pulmonary gas exchange deteriorated [from a partial arterial O2 pressure-to-inspired O2 fraction ratio (PaO2 /Fi O2 ) of 254 at baseline to 187 after 4 h HCl]. In addition, pulmonary artery pressure and total pulmonary vascular resistance increased (from 16 to 19 mmHg and from 133 to 154 dyn · s · cm−5, respectively). In NaCl-treated animals, only the central venous pressure significantly increased (from 7 to 9 mmHg). Distribution of pulmonary perfusion (measured with fluorescent microspheres) changed differently in both groups. After HCl application, 6% more blood flow was directed to the treated lung, whereas, after NaCl, 5% more blood flow was directed to the untreated lung. HCl and NaCl treatment both induce an equivalent lung edema, but only HCl treatment is associated with gas exchange alteration and tissue damage. Redistribution of pulmonary perfusion maintains gas exchange during NaCl treatment and decreases it during HCl inhalation.

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The Unpredictable Effect of Changing Cardiac Output on Hypoxemia after Acute Pulmonary Thromboembolism

Clinical medicine Circulatory respiratory and pulmonary medicine ◽

10.4137/ccrpm.s773 ◽

2008 ◽

Vol 2 ◽

pp. CCRPM.S773

Author(s):

John Y. C. Tsang ◽

Wayne J. E. Lamm ◽

Blazej Neradilek ◽

Nayak L. Polissar ◽

Michael P. Hlastala

Keyword(s):

Cluster Analysis ◽

Blood Flow ◽

Cardiac Output ◽

Gas Exchange ◽

Clinical Setting ◽

Pulmonary Thromboembolism ◽

Regional Blood Flow ◽

The Other ◽

Fluorescent Microspheres ◽

Acute Pulmonary Thromboembolism

Previous studies reported that the degree of hypoxemia following acute pulmonary thromboembolism (APTE) was highly variable and that its mechanism was mainly due to the creation of many high and low ventilation/perfusion (V/Q) units, as a result of the heterogeneous regional blood flow (Q) caused by embolic obstruction. We studied the effect of changing cardiac output (Qt) on gas exchange after APTE in 5 embolized piglets (23 ± 3 Kg), using Dobutamine intermittently at approximately 20 μg/kg/min for 120 minutes. The distribution of ventilation (V) and perfusion (Q) at various times was mapped using fluorescent microspheres in 941 ± 60 lung regions. After APTE, increase in Qt by Dobutamine improved venous oxygen tension (PvO2) but arterial PaO2 did not change consistently. On the other hand, cluster analysis showed that the V/Q ratio of most lung regions was lowered due to increases in Q at the same time. We concluded that the effect of changing cardiac output on gas exchange following APTE was affected by the simultaneous and varying balance between the changing V/Q mismatch and the concomitantly changing PvO2, which might explain the unpredictability of PaO2 in the clinical setting.

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Increased cardiac output, not pulmonary artery systolic pressure, increases blood flow through intrapulmonary arteriovenous anastomoses and impairs pulmonary gas exchange efficiency (717.2)

The FASEB Journal ◽

10.1096/fasebj.28.1_supplement.717.2 ◽

2014 ◽

Vol 28 (S1) ◽

Author(s):

Jonathan Elliott ◽

Joseph Duke ◽

Joel Futral ◽

Randall Goodman ◽

Jerold Hawn ◽

...

Keyword(s):

Blood Flow ◽

Cardiac Output ◽

Gas Exchange ◽

Pulmonary Artery ◽

Systolic Pressure ◽

Pulmonary Gas Exchange ◽

Pulmonary Artery Systolic Pressure ◽

Arteriovenous Anastomoses ◽

Flow Through

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Mechanisms of improvement in pulmonary gas exchange during isovolemic hemodilution

Journal of Applied Physiology ◽

10.1152/jappl.1999.87.1.132 ◽

1999 ◽

Vol 87 (1) ◽

pp. 132-141 ◽

Cited By ~ 39

Author(s):

Steven Deem ◽

Richard G. Hedges ◽

Steven McKinney ◽

Nayak L. Polissar ◽

Michael K. Alberts ◽

...

Keyword(s):

Blood Flow ◽

Fractal Dimension ◽

Gas Exchange ◽

Spatial Correlation ◽

Pulmonary Blood Flow ◽

Minute Ventilation ◽

Flow Distribution ◽

Pulmonary Gas Exchange ◽

Normal Lung ◽

Blood Flow Distribution

Severe anemia is associated with remarkable stability of pulmonary gas exchange (S. Deem, M. K. Alberts, M. J. Bishop, A. Bidani, and E. R. Swenson. J. Appl. Physiol. 83: 240–246, 1997), although the factors that contribute to this stability have not been studied in detail. In the present study, 10 Flemish Giant rabbits were anesthetized, paralyzed, and mechanically ventilated at a fixed minute ventilation. Serial hemodilution was performed in five rabbits by simultaneous withdrawal of blood and infusion of an equal volume of 6% hetastarch; five rabbits were followed over a comparable time. Ventilation-perfusion (V˙a/Q˙) relationships were studied by using the multiple inert-gas-elimination technique, and pulmonary blood flow distribution was assessed by using fluorescent microspheres. Expired nitric oxide (NO) was measured by chemiluminescence. Hemodilution resulted in a linear fall in hematocrit over time, from 30 ± 1.6 to 11 ± 1%. Anemia was associated with an increase in arterial [Formula: see text] in comparison with controls ( P < 0.01 between groups). The improvement in O2 exchange was associated with reducedV˙a/Q˙heterogeneity, a reduction in the fractal dimension of pulmonary blood flow ( P = 0.04), and a relative increase in the spatial correlation of pulmonary blood flow ( P = 0.04). Expired NO increased with anemia, whereas it remained stable in control animals ( P < 0.0001 between groups). Anemia results in improved gas exchange in the normal lung as a result of an improvement in overallV˙a/Q˙matching. In turn, this may be a result of favorable changes in pulmonary blood flow distribution, as assessed by the fractal dimension and spatial correlation of blood flow and as a result of increased NO availability.

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Elevated central venous pressure is associated with impairment of microcirculatory blood flow in sepsis: a hypothesis generating post hoc analysis

BMC Anesthesiology ◽

10.1186/1471-2253-13-17 ◽

2013 ◽

Vol 13 (1) ◽

Cited By ~ 61

Author(s):

Namkje AR Vellinga ◽

Can Ince ◽

E Christiaan Boerma

Keyword(s):

Blood Flow ◽

Central Venous Pressure ◽

Venous Pressure ◽

Central Venous ◽

Microcirculatory Blood Flow ◽

Post Hoc Analysis ◽

Post Hoc

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AACN Practice Alert: Pulmonary Artery/Central Venous Pressure Monitoring in Adults

AACN Advanced Critical Care ◽

10.4037/aacnacc2020328 ◽

2020 ◽

Vol 31 (1) ◽

pp. 41-48

Keyword(s):

Pulmonary Artery ◽

Central Venous Pressure ◽

Venous Pressure ◽

Pressure Monitoring ◽

Central Venous ◽

Central Venous Pressure Monitoring

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Central venous pressure and pulmonary artery pressure monitoring

Anaesthesia & intensive care medicine ◽

10.1016/j.mpaic.2018.01.004 ◽

2018 ◽

Vol 19 (4) ◽

pp. 189-193 ◽

Cited By ~ 3

Author(s):

Michael Gilbert

Keyword(s):

Pulmonary Artery ◽

Central Venous Pressure ◽

Pulmonary Artery Pressure ◽

Venous Pressure ◽

Pressure Monitoring ◽

Central Venous ◽

Artery Pressure

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Impaired pulmonary gas exchange efficiency, but normal pulmonary artery pressure increases, with hypoxia in men and women with a patent foramen ovale

Experimental Physiology ◽

10.1113/ep088750 ◽

2020 ◽

Vol 105 (9) ◽

pp. 1648-1659

Author(s):

Joseph W. Duke ◽

Kara M. Beasley ◽

Julia P. Speros ◽

Jonathan E. Elliott ◽

Steven S. Laurie ◽

...

Keyword(s):

Gas Exchange ◽

Pulmonary Artery ◽

Pulmonary Artery Pressure ◽

Patent Foramen Ovale ◽

Pulmonary Gas Exchange ◽

Foramen Ovale ◽

Men And Women ◽

Artery Pressure

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Pulmonary gas exchange response to exercise- and mannitol-induced bronchoconstriction in mild asthma

Journal of Applied Physiology ◽

10.1152/japplphysiol.00108.2008 ◽

2008 ◽

Vol 105 (5) ◽

pp. 1477-1485 ◽

Cited By ~ 27

Author(s):

Phillip A. Muñoz ◽

Federico P. Gómez ◽

Hernán A. Manrique ◽

Josep Roca ◽

Joan A. Barberà ◽

...

Keyword(s):

Blood Flow ◽

Gas Exchange ◽

Minute Ventilation ◽

Forced Expiratory Volume ◽

Pulmonary Gas Exchange ◽

Slow Recovery ◽

Airway Narrowing ◽

Asthmatic Patients ◽

Response To Exercise ◽

Blood Flow Redistribution

Both exercise (EIB) and mannitol challenges were performed in asthmatic patients to assess and compare their pulmonary gas exchange responses for an equivalent degree of bronchoconstriction. In 11 subjects with EIB [27 ± 4 (SD) yr; forced expiratory volume in 1 s (FEV1), 86 ± 8% predicted], ventilation-perfusion (V̇a/Q̇) distributions (using multiple inert gas elimination technique) were measured 5, 15, and 45 min after cycling exercise (FEV1 fall, 35 ± 12%) and after mannitol (33 ± 10%), 1 wk apart. Five minutes after EIB, minute ventilation (V̇e; by 123 ± 60%), cardiac output (Q̇t, by 48 ± 29%), and oxygen uptake (V̇o2; by 54 ± 25%) increased, whereas arterial Po2 (PaO2; by 14 ± 11 Torr) decreased due to moderate V̇a/Q̇ imbalance, assessed by increases in dispersions of pulmonary blood flow (log SDQ̇; by 0.53 ± 0.16) and alveolar ventilation (log SDV̇; by 0.28 ± 0.15) (dimensionless) ( P < 0.01 each). In contrast, for an equivalent degree of bronchoconstriction and minor increases in V̇e, Q̇t, and V̇o2, mannitol decreased PaO2 more intensely (by 24 ± 9 Torr) despite fewer disturbances in log SDQ̇ (by 0.27 ± 0.12). Notwithstanding, mannitol-induced increase in log SDV̇ at 5 min (by 0.35 ± 0.15) was similar to that observed during EIB, as was the slow recovery in log SDV̇ and high V̇a/Q̇ ratio areas, at variance with the faster recovery of log SDQ̇ and low V̇a/Q̇ ratio areas. In asthmatic individuals, EIB provokes more V̇a/Q̇ imbalance but less hypoxemia than mannitol, primarily due to postexercise increases in V̇e and Q̇t benefiting PaO2. V̇a/Q̇ inequalities during both challenges most likely reflect uneven airway narrowing and blood flow redistribution generating distinctive V̇a/Q̇ patterns, including the development of areas with low and high V̇a/Q̇ ratios.

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Bronchial circulation in pulmonary artery occlusion and reperfusion

Journal of Applied Physiology ◽

10.1152/jappl.1990.68.1.125 ◽

1990 ◽

Vol 68 (1) ◽

pp. 125-129 ◽

Cited By ~ 26

Author(s):

T. F. Kowalski ◽

S. Guidotti ◽

M. Deffebach ◽

P. Kubilis ◽

M. Bishop

Keyword(s):

Blood Flow ◽

Pulmonary Artery ◽

Morphological Changes ◽

Ischemia Reperfusion ◽

Artery Occlusion ◽

Arterial Blood Flow ◽

Lung Edema ◽

Base Line ◽

Bronchial Circulation ◽

Arterial Blood

Obstruction of pulmonary arterial blood flow results in minimal biochemical and/or morphological changes in the involved lung. If the lung is reperfused, a syndrome of leukopenia and lung edema occurs. We used the radiolabeled microsphere technique to measure the response of the bronchial circulation in rabbits to acute pulmonary artery occlusion (PAO) and to pulmonary artery reperfusion. We found that the bronchial blood flow (Qbr) decreased from a base line of 0.37 +/- 0.10 to 0.09 +/- 0.04 (SE) ml.min-1.g dry lung-1 (P less than or equal to 0.05) after 4 h of PAO. In a separate group of animals, Qbr 24 h after PAO remained low (0.20 +/- 0.07 ml.min-1.g dry lung-1, P = 0.06). Qbr during PAO was inversely correlated with the wet-to-dry ratio after reperfusion (r = -0.68, P = 0.06). Qbr did not change during 4 h of reperfusion. We speculate that a critical level of Qbr may be necessary during PAO to prevent ischemia/reperfusion injury from occurring.

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