Bronchial circulation in pulmonary artery occlusion and reperfusion

1990 ◽  
Vol 68 (1) ◽  
pp. 125-129 ◽  
Author(s):  
T. F. Kowalski ◽  
S. Guidotti ◽  
M. Deffebach ◽  
P. Kubilis ◽  
M. Bishop

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.

1985 ◽  
Vol 58 (4) ◽  
pp. 1225-1230 ◽  
Author(s):  
S. Gelman ◽  
K. C. Fowler ◽  
S. P. Bishop ◽  
L. R. Smith

Cardiac output distribution and regional blood flow were studied during hypocarbia independent of changes in ventilatory parameters. Fifteen cynomolgus monkeys were anesthetized with methohexital sodium (8 mg/kg im) and hyperventilated through an endotracheal tube. Hypocarbia at two levels, 28 +/- 1.8 and 17 +/- 0.6 Torr, was achieved by a stepwise decreasing CO2 flow into the semiclosed system. Regional blood flow was determined with labeled microspheres. At each stage of experiments two sets of microspheres (9 and 15 microns diam) were used simultaneously. The use of two microsphere sizes allowed evaluation of the relationship between total (nutritive and nonnutritive) tissue blood flow, determined with 15-microns spheres, and nutritive blood flow, determined with 9-microns spheres. There was no change in cardiac output or arterial pressure during both degrees of studied hypocarbia. Hypocarbia was accompanied by a decrease in myocardial blood flow determined with 15-microns spheres and preservation of the flow determined with 9-microns spheres. Splenic blood flow was decreased, whereas hepatic arterial blood flow was increased during both levels of hypocarbia. Blood flow through the brain, renal cortex, and gut showed a biphasic response to hypocarbia: during hypocarbia at 28 +/- 1.8 Torr, blood flow determined with 15-microns spheres was unchanged (in the gut) or decreased (in the brain and kidneys), whereas blood flow determined with 9-microns spheres was decreased. During hypocarbia at 17 +/- 0.6 Torr, blood flow determined with 9-microns spheres had a tendency to restore to base-line values.


2018 ◽  
Vol 59 (12) ◽  
pp. 1482-1486 ◽  
Author(s):  
Chiho Tokunaga ◽  
Shonosuke Matsushita ◽  
Hiroaki Sakamoto ◽  
Kazuyuki Hyodo ◽  
Misao Kubota ◽  
...  

Background Increased pulmonary blood flow (PBF) and shear stress may provoke irreversible vascular remodeling, yet invasive visualization of the microvasculature complicates monitoring. A non-invasive imaging methodology would therefore safely provide mechanistic insights into the progression of high PBF-induced vascular remodeling. Purpose To establish a novel microvasculature visualization method using synchrotron radiation pulmonary microangiography (SRPA) that can also calculate PBF velocity in vivo. Material and Methods A high PBF rat model was established by making a fistula between the abdominal aorta and inferior vena cava. After eight weeks, SRPA was performed and the dynamic density changes in the right lower pulmonary artery (PA) were calculated by software. SRPA was performed with a HARP (High-Gain Avalanche Rushing amorphous Photoconductor) receiver. PBF velocity was calculated by contrast medium transit time within the PA. All data were presented as mean ± standard error (SE). Student's t-test was used for comparison between the two groups. Results High dynamic spatial and contrast resolution from SRPA in the PA allowed for clear pulmonary microangiography and accurate detection of higher PBF in the rat model (82.3 ± 8.5 mm/s high-PBF group vs. 46.1 ± 4.3 mm/s control group, P < 0.01). Conclusions These novel results demonstrate that SRPA was useful in both visualizing the dynamic flow distribution within the microvasculature and calculating PBF velocity. This newly developed, non-invasive technology may become a powerful tool in clarifying the mechanism of vascular remodeling associated with high PBF-induced shear stress.


2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 353
Author(s):  
Jayasree Nair ◽  
Lauren Davidson ◽  
Sylvia Gugino ◽  
Carmon Koenigsknecht ◽  
Justin Helman ◽  
...  

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.


2015 ◽  
Vol 26 (8) ◽  
pp. 2779-2789 ◽  
Author(s):  
Claus Christian Pieper ◽  
Winfried A. Willinek ◽  
Daniel Thomas ◽  
Hojjat Ahmadzadehfar ◽  
Markus Essler ◽  
...  

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