scholarly journals Effects of low and high tidal volume and pentoxifylline on intestinal blood flow and leukocyte-endothelial interactions in mechanically ventilated rats

Critical Care ◽  
2012 ◽  
Vol 16 (S1) ◽  
Author(s):  
N Nakagawa ◽  
P Aikawa ◽  
HZ Zhang ◽  
C Correia ◽  
R Pazzeti ◽  
...  
Keyword(s):  
Blood Flow ◽  
Tidal Volume ◽  
Intestinal Blood Flow ◽  
High Tidal Volume ◽  
Mechanically Ventilated

scholarly journals Tidal volume dependency of gas exchange in bronchoconstricted pig lungs

2007 ◽  
Vol 103 (1) ◽  
pp. 148-155 ◽  
Author(s):  
Axel Kleinsasser ◽  
I. Mark Olfert ◽  
Alex Loeckinger ◽  
G. Kim Prisk ◽  
Susan R. Hopkins ◽  
...  
Keyword(s):  
Tidal Volume ◽  
Dynamic Compliance ◽  
Inert Gas ◽  
High Tidal Volume ◽  
Pulmonary Resistance ◽  
Mechanically Ventilated ◽  
High Tidal Volume Ventilation ◽  
Volume Ventilation ◽  
Closed Airway

Independent of airway pressure, pulmonary resistance is known to fall with increasing tidal volumes, traditionally thought to result from radial traction on the airways. R. C. Anafi and T. A. Wilson ( J Appl Physiol 91: 1185–1192, 2001) recently presented a model of a single terminal airway that explains the tidal volume-associated fall in resistance with an additional mechanism pertinent to narrow airways: a stable, nearly closed airway that is challenged with an increase in tidal volume “pops open” to become a stable, well-opened airway, and thus resistance drops suddenly. To test this model in vivo, the effects of high (24 ml/kg) and low (9 ml/kg) tidal volume in bronchoconstricted lungs were assessed using 1) the multiple inert gas elimination technique (MIGET) and 2) a 15-breath multiple breath inert gas washout (MBW) technique in anesthetized pigs. With high tidal volume, ventilation/perfusion (V̇a/Q̇) mismatch was reduced (log SD Q̇ from 1.30 ± 0.11 to 1.09 ± 0.12, P < 0.05), and blood flow to lung units with V̇a/Q̇ ratios < 0.1 was significantly reduced (37 ± 4% of cardiac output to 7 ± 4%, P < 0.05). Dynamic compliance was twice as high during high-tidal-volume ventilation ( P = 0.002). MBW analysis revealed that, while heterogeneity of ventilation during bronchoconstriction was not significantly different between either low or high tidal volume (log SD V̇mbw = 1.39 ± 0.09 and 1.34 ± 0.02, respectively), preinspiratory lung volume (PILV) decreased by 42% with low-tidal-volume ventilation ( P < 0.05), whereas it did not change with high-tidal-volume ventilation. The higher PILV during high tidal volume is also consistent with Anafi and Wilson's model. In summary, the outcomes from MIGET, and to some extent the MBW, in our anesthetized and mechanically ventilated pigs are consistent with a bistable terminal airway model as proposed by Anafi and Wilson. However, our data do not allow exclusion of other mechanisms that may lead to improved ventilatory distribution when tidal volume is increased.

Lung overexpansion increases pulmonary microvascular protein permeability in young lambs

1990 ◽  
Vol 69 (2) ◽  
pp. 577-583 ◽  
Author(s):  
D. P. Carlton ◽  
J. J. Cummings ◽  
R. G. Scheerer ◽  
F. R. Poulain ◽  
R. D. Bland
Keyword(s):  
Mechanical Ventilation ◽  
Blood Flow ◽  
Tidal Volume ◽  
Lymph Flow ◽  
Base Line ◽  
Inflation Pressure ◽  
Mechanically Ventilated ◽  
Altered Protein ◽  
Pulmonary Microcirculation ◽  
Protein Permeability

To study the effects of inflation pressure and tidal volume (VT) on protein permeability in the neonatal pulmonary microcirculation, we measured lung vascular pressures, blood flow, lymph flow (QL), and concentrations of protein in lymph (L) and plasma (P) of 22 chronically catheterized lambs that received mechanical ventilation at various peak inflation pressures (PIP) and VT. Nine lambs were ventilated initially with a PIP of 19 +/- 1 cmH2O and a VT of 10 +/- 1 ml/kg for 2-4 h (base line), after which we overexpanded their lungs with a PIP of 58 +/- 3 cmH2O and a VT of 48 +/- 4 ml/kg for 4-8 h. QL increased from 2.1 +/- 0.4 to 13.9 +/- 5.0 ml/h. L/P did not change, but the ratio of albumin to globulin in lymph relative to the same ratio in plasma decreased, indicating altered protein sieving in the pulmonary microcirculation. Seven other lambs were mechanically ventilated for 2-4 h at a PIP of 34 +/- 1 cmH2O and a VT of 23 +/- 2 ml/kg (base line), after which their chest and abdomen were bound so that PIP increased to 54 +/- 1 cmH2O for 4-6 h without a change in VT. QL decreased on average from 2.8 +/- 0.6 to 1.9 +/- 0.3 ml/h (P = 0.08), and L/P was unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of the chinese herbal medicine Dai-Kenchu-To on intestinal blood flow

2001 ◽  
Vol 120 (5) ◽  
pp. A248-A248
Author(s):  
N KAWASAKI ◽  
K NARIAI ◽  
M NAKAO ◽  
K NAKADA ◽  
N HANYUU ◽  
...  
Keyword(s):  
Blood Flow ◽  
Herbal Medicine ◽  
Chinese Herbal Medicine ◽  
Intestinal Blood Flow ◽  
Chinese Herbal

The effect of early-onset preeclampsia on the intestinal blood flow of preterm infants

2019 ◽  
pp. 1-5 ◽  
Author(s):  
Simone Manso de Carvalho Pelicia ◽  
Saskia Maria Wiegerinck Fekete ◽  
José Eduardo Corrente ◽  
Ligia Maria Suppo de Souza Rugolo
Keyword(s):  
Blood Flow ◽  
Preterm Infants ◽  
Early Onset ◽  
Intestinal Blood Flow ◽  
Early Onset Preeclampsia

Effects of nicotine on canine intestinal blood flow and oxygen consumption

1984 ◽  
Vol 246 (2) ◽  
pp. G195-G203
Author(s):  
R. H. Gallavan ◽  
Y. Tsuchiya ◽  
E. D. Jacobson
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Muscle Tension ◽  
Intestinal Blood Flow ◽  
Mesenteric Blood Flow ◽  
State Response ◽  
Arterial Blood ◽  
Intestinal Circulation

The purpose of this study was to determine the effects of nicotine on intestinal blood flow and oxygen consumption. The intravenous infusion of nicotine at doses corresponding to those experienced by smokers produced a transient increase in systemic arterial blood pressure and mesenteric blood flow. Subsequently a steady-state response developed that consisted of a reduction in mesenteric blood flow due to both a decrease in blood pressure and an increase in intestinal vascular resistance. This increase in resistance was probably due to increased levels of circulating catecholamines. The intra-arterial infusion of nicotine into the intestinal circulation at doses experienced by the average smoker had no effect on either intestinal blood flow or oxygen consumption. Similarly, under in vitro conditions nicotine had no direct effect on intestinal vascular smooth muscle tension. Thus, nicotine appears to reduce intestinal blood flow indirectly as a result of its systemic effects.

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