Effects of anemia and hemorrhagic shock on pulmonary diffusion in the dog lung

1963 ◽  
Vol 18 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Benjamin Burrows ◽  
Albert H. Niden
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
Blood Cell ◽  
Hemorrhagic Shock ◽  
Red Blood Cell ◽  
Lung Volume ◽  
Diffusing Capacity ◽  
Pulmonary Diffusing Capacity ◽  
Capillary Membrane ◽  
Alveolar Capillary

Hemorrhagic shock induced a marked fall in the pulmonary diffusing capacity for carbon monoxide in the dog (Dl) and produced marked nonuniformity of Dl/Va ratios throughout the lung as assessed by the “equilibration technique”. Difficulties in calculating over-all Dl under these conditions are discussed. Induced anemia also produced a fall in Dl, but little change in the uniformity of Dl/Va ratios was noted. In isolated perfused dog lungs where blood flow, pulmonary vascular pressures, lung volume, and ventilation were maintained constant, Dl was found to be proportional to hematocrit, suggesting either: 1) that virtually all resistance to CO diffusion is in the erythrocyte or 2) that the apparent diffusing capacity of the alveolar-capillary membrane is dependent upon hematocrit, carbon monoxide transfer being reduced across portions of membrane which are some distance from a red blood cell. Submitted on January 12, 1962

Effect of negative intra-alveolar pressure on pulmonary diffusing capacity

1960 ◽  
Vol 15 (3) ◽  
pp. 372-376 ◽  
Author(s):  
J. E. Cotes ◽  
D. P. Snidal ◽  
R. H. Shepard
Keyword(s):  
Carbon Monoxide ◽  
Venous Pressure ◽  
Capillary Blood ◽  
Breath Holding ◽  
Diffusing Capacity ◽  
Alveolar Pressure ◽  
Holding Period ◽  
Capillary Membrane ◽  
Capillary Blood Volume ◽  
Alveolar Capillary

In one of two subjects studied in detail, using 0.1% carbon monoxide in the test gas and a 10-second breath-holding period, the alveolar capillary blood volume (Vc) was found to increase by nearly 100% when the intra-alveolar pressure was made negative during breath holding. This was accompanied by a reduction in venous pressure in the forearm. In both subjects Vc was increased on exercise. The diffusing capacity of the alveolar capillary membrane (Dm) remained relatively constant in spite of large changes in Vc. The findings suggest that stationary blood is present in some alveolar capillaries at rest. The implications of this finding and a likely mechanism for the increase in Vc with negative pressure are discussed. xsSubmitted on September 14, 1959

Trauma-hemorrhagic shock-induced red blood cell damage leads to decreased microcirculatory blood flow*

2009 ◽  
Vol 37 (3) ◽  
pp. 1000-1010 ◽  
Author(s):  
George W. Machiedo ◽  
Sergey B. Zaets ◽  
Tamara L. Berezina ◽  
Da-Zhong Xu ◽  
Eleonora Feketova ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Hemorrhagic Shock ◽  
Red Blood Cell ◽  
Cell Damage ◽  
Microcirculatory Blood Flow

Saturation kinetics for steady-state pulmonary CO transfer

1977 ◽  
Vol 43 (5) ◽  
pp. 880-884 ◽  
Author(s):  
C. Mendoza ◽  
H. Peavy ◽  
B. Burns ◽  
G. Gurtner
Keyword(s):  
Carbon Monoxide ◽  
Steady State ◽  
Reaction Rate ◽  
Back Pressure ◽  
Diffusing Capacity ◽  
Pulmonary Capillary ◽  
Capillary Membrane ◽  
Saturation Kinetics ◽  
Co Concentration ◽  
Alveolar Capillary

Steady-state diffusing capacity of the lungs for carbon monoxide (DLCO) was measured in 13 anesthetized, paralyzed dogs ventilated at constant tidal volume and rate, using four different inspired CO levels (190, 600, 1,110, and 2,000 ppm). DLCO increased and reached a maximum as the inspired CO level was raised from 190 to 600 ppm. Further increases in inspired CO concentration were accompanied by a decrease in inspired CO concentration were accompanied by a decrease in DLCO. CO dead space and Pao2 remained constant at all inspired O2 levels. In some experiments a second set of measurements was made, the results of which were similar to those of the first set. The results cannot be explained by changes in CO back pressure, pulmonary capillary volume, or reaction rate of CO with hemoglobin, but can be explained if there is carrier-mediated CO transport in the alveolar capillary membrane.

Alveolar diffusion-perfusion interactions during high-altitude residence in guinea pigs

2007 ◽  
Vol 102 (6) ◽  
pp. 2179-2185 ◽  
Author(s):  
Cuneyt Yilmaz ◽  
D. Merrill Dane ◽  
Connie C. W. Hsia
Keyword(s):  
Carbon Monoxide ◽  
Blood Flow ◽  
High Altitude ◽  
Lung Volume ◽  
Guinea Pigs ◽  
Pulmonary Blood Flow ◽  
Ultrastructural Changes ◽  
Diffusing Capacity ◽  
Adaptive Responses ◽  
Structural Adaptation

We previously reported in weanling guinea pigs raised at high altitude (HA; 3,800 m) an elevated lung diffusing capacity estimated by morphometry from alveolar-capillary surface area, harmonic mean blood-gas barrier thickness, and pulmonary capillary blood volume (Vc) compared with litter-matched control animals raised at an intermediate altitude (IA; 1,200 m) (Hsia CCW, Polo Carbayo JJ, Yan X, Bellotto DJ. Respir Physiol Neurobiol 147: 105–115, 2005). To determine if HA-induced alveolar ultrastructural changes are associated with improved alveolar function, we measured lung diffusing capacity for carbon monoxide (DlCO), membrane diffusing capacity for carbon monoxide (DmCO), Vc, pulmonary blood flow, and lung volume by a rebreathing technique in litter-matched male weanling Hartley guinea pigs raised at HA or IA for 4 or 12 mo. Separate control animals were also raised and studied at sea level (SL). Resting measurements were obtained in the conscious nonsedated state. In HA animals compared with corresponding IA or SL controls, lung volume and hematocrit were significantly higher while pulmonary blood flow was lower. At a given pulmonary blood flow, DlCO and DmCO were higher in HA-raised animals than in control animals without a significant change in Vc. We conclude that 1) HA residence enhanced physiological diffusing capacity corresponding to that previously estimated on the basis of structural adaptation, 2) adaptation in diffusing capacity and its components should be interpreted with respect to pulmonary blood flow, and 3) this noninvasive rebreathing technique could be used to follow adaptive responses in small animals.

In vivo microvascular structural and functional consequences of muscle length changes

1997 ◽  
Vol 272 (5) ◽  
pp. H2107-H2114 ◽  
Author(s):  
D. C. Poole ◽  
T. I. Musch ◽  
C. A. Kindig
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Oxygen Delivery ◽  
Sarcomere Length ◽  
Flow Dynamics ◽  
Capillary Diameter ◽  
Luminal Diameter ◽  
Length Changes

As muscles are stretched, blood flow and oxygen delivery are compromised, and consequently muscle function is impaired. We tested the hypothesis that the structural microvascular sequellae associated with muscle extension in vivo would impair capillary red blood cell hemodynamics. We developed an intravital spinotrapezius preparation that facilitated direct on-line measurement and alteration of sarcomere length simultaneously with determination of capillary geometry and red blood cell flow dynamics. The range of spinotrapezius sarcomere lengths achievable in vivo was 2.17 +/- 0.05 to 3.13 +/- 0.11 microns. Capillary tortuosity decreased systematically with increases of sarcomere length up to 2.6 microns, at which point most capillaries appeared to be highly oriented along the fiber longitudinal axis. Further increases in sarcomere length above this value reduced mean capillary diameter from 5.61 +/- 0.03 microns at 2.4-2.6 microns sarcomere length to 4.12 +/- 0.05 microns at 3.2-3.4 microns sarcomere length. Over the range of physiological sarcomere lengths, bulk blood flow (radioactive microspheres) decreased approximately 40% from 24.3 +/- 7.5 to 14.5 +/- 4.6 ml.100 g-1.min-1. The proportion of continuously perfused capillaries, i.e., those with continuous flow throughout the 60-s observation period, decreased from 95.9 +/- 0.6% at the shortest sarcomere lengths to 56.5 +/- 0.7% at the longest sarcomere lengths and was correlated significantly with the reduced capillary diameter (r = 0.711, P < 0.01; n = 18). We conclude that alterations in capillary geometry and luminal diameter consequent to increased muscle sarcomere length are associated with a reduction in mean capillary red blood cell velocity and a greater proportion of capillaries in which red blood cell flow is stopped or intermittent. Thus not only does muscle stretching reduce bulk blood (and oxygen) delivery, it also alters capillary red blood cell flow dynamics, which may further impair blood-tissue oxygen exchange.

Influence of microflow on hepatic sinusoid blood flow and red blood cell deformation

2021 ◽  
Author(s):  
Tianhao Wang ◽  
Shouqin Lü ◽  
Yinjing Hao ◽  
Zinan Su ◽  
Mian Long ◽  
...  
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Deformation ◽  
Hepatic Sinusoid
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