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Bruce A. Harms - One of the best experts on this subject based on the ideXlab platform.
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Lung lymph Oncotic Pressure may not modulate pulmonary vascular filtration in sheep.
American journal of respiratory and critical care medicine, 1997Co-Authors: Robert L. Conhaim, Gregory A. Myers, A M Mcgrath, S D Cooler, David A. Deangeles, Bruce A. HarmsAbstract:We tested the hypothesis that plasma Oncotic Pressure alone, not the plasma-to-lymph Oncotic Pressure difference, modulates pulmonary transvascular fluid filtration. To do this we measured lung lymph flow after raising left atrial Pressure (by inflating a balloon) in sheep that were receiving a continuous (32 h) infusion of dextran 40. For comparison, we also raised left atrial Pressure elevation, plasma Oncotic Pressures in dextran and control sheep, respectively, were 39.5 +/- 4.5 and 17.7 +/- 2.2 mm Hg; plasma-to-lymph Oncotic Pressure gradients, respectively, were 4.4 +/- 0.6 and 4.4 +/- 0.6 mm Hg. Left atrial Pressure elevation during dextran infusion increased lung lymph flow by a factor of 2.4 +/- 0.4, compared with a factor of 4.2 +/- 2.3 in control sheep. Thus, left atrial Pressure elevation increased lymph flow less in dextran-treated animals than in control animals, even though the plasma-to-lymph Oncotic Pressure gradients were equal. This suggests that plasma Oncotic Pressure alone may be a more important determinant of pulmonary transvascular fluid filtration than the plasma-to-lymph Oncotic Pressure difference.
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Effects of pentafraction and hetastarch plasma expansion on lung and soft tissue transvascular fluid filtration.
Surgery, 1995Co-Authors: Gregory A. Myers, Robert L. Conhaim, David J. Rosenfeld, Bruce A. HarmsAbstract:Background. Hetastarch and pentafraction are high molecular weight starch solutions designed to augment plasma Oncotic Pressure. Although clinical utilization of hetastarch has been limited by reported coagulation abnormalities, pentafraction is a newer derivative that appears to have few adverse hemostatic effects. We examined the ability of pentafraction to modulate lung and soft tissue transvascular fluid filtration under hypoproteinemic conditions compared with hetastarch and Ringer's lactate (LR). Methods. Awake, protein-depleted sheep (n=19) were prepared with lung and soft tissue lymph fistulas, and comparable infusions of 5% pentafraction (n=6), 6% hetastarch (n=6), or LR (n=7) were administered. Plasma and lymph samples were collected during 24-hour period to determine changes in protein concentrations, plasma-to-lymph Oncotic gradients, and lung (QL) and soft tissue (QS) lymph flows. Results. QL and QS rose nearly twofold after protein depletion alone. LR infusion increased QL and QS to 8.7±1.7 and 3.1±0.6 times normoproteinemic baseline, respectively (p Conclusions. Both hetastarch and pentafraction limit transvascular fluid filtration under hypoproteinemic conditions by augmenting plasma Oncotic Pressure and the plasma-to-lymph Oncotic Pressure gradient. Because of fewer adverse hemostatic effects pentafraction may be an improvement over current therapies in critical care fluid management.
Gregory A. Myers - One of the best experts on this subject based on the ideXlab platform.
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Lung lymph Oncotic Pressure may not modulate pulmonary vascular filtration in sheep.
American journal of respiratory and critical care medicine, 1997Co-Authors: Robert L. Conhaim, Gregory A. Myers, A M Mcgrath, S D Cooler, David A. Deangeles, Bruce A. HarmsAbstract:We tested the hypothesis that plasma Oncotic Pressure alone, not the plasma-to-lymph Oncotic Pressure difference, modulates pulmonary transvascular fluid filtration. To do this we measured lung lymph flow after raising left atrial Pressure (by inflating a balloon) in sheep that were receiving a continuous (32 h) infusion of dextran 40. For comparison, we also raised left atrial Pressure elevation, plasma Oncotic Pressures in dextran and control sheep, respectively, were 39.5 +/- 4.5 and 17.7 +/- 2.2 mm Hg; plasma-to-lymph Oncotic Pressure gradients, respectively, were 4.4 +/- 0.6 and 4.4 +/- 0.6 mm Hg. Left atrial Pressure elevation during dextran infusion increased lung lymph flow by a factor of 2.4 +/- 0.4, compared with a factor of 4.2 +/- 2.3 in control sheep. Thus, left atrial Pressure elevation increased lymph flow less in dextran-treated animals than in control animals, even though the plasma-to-lymph Oncotic Pressure gradients were equal. This suggests that plasma Oncotic Pressure alone may be a more important determinant of pulmonary transvascular fluid filtration than the plasma-to-lymph Oncotic Pressure difference.
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Effects of pentafraction and hetastarch plasma expansion on lung and soft tissue transvascular fluid filtration.
Surgery, 1995Co-Authors: Gregory A. Myers, Robert L. Conhaim, David J. Rosenfeld, Bruce A. HarmsAbstract:Background. Hetastarch and pentafraction are high molecular weight starch solutions designed to augment plasma Oncotic Pressure. Although clinical utilization of hetastarch has been limited by reported coagulation abnormalities, pentafraction is a newer derivative that appears to have few adverse hemostatic effects. We examined the ability of pentafraction to modulate lung and soft tissue transvascular fluid filtration under hypoproteinemic conditions compared with hetastarch and Ringer's lactate (LR). Methods. Awake, protein-depleted sheep (n=19) were prepared with lung and soft tissue lymph fistulas, and comparable infusions of 5% pentafraction (n=6), 6% hetastarch (n=6), or LR (n=7) were administered. Plasma and lymph samples were collected during 24-hour period to determine changes in protein concentrations, plasma-to-lymph Oncotic gradients, and lung (QL) and soft tissue (QS) lymph flows. Results. QL and QS rose nearly twofold after protein depletion alone. LR infusion increased QL and QS to 8.7±1.7 and 3.1±0.6 times normoproteinemic baseline, respectively (p Conclusions. Both hetastarch and pentafraction limit transvascular fluid filtration under hypoproteinemic conditions by augmenting plasma Oncotic Pressure and the plasma-to-lymph Oncotic Pressure gradient. Because of fewer adverse hemostatic effects pentafraction may be an improvement over current therapies in critical care fluid management.
Robert L. Conhaim - One of the best experts on this subject based on the ideXlab platform.
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Lung lymph Oncotic Pressure may not modulate pulmonary vascular filtration in sheep.
American journal of respiratory and critical care medicine, 1997Co-Authors: Robert L. Conhaim, Gregory A. Myers, A M Mcgrath, S D Cooler, David A. Deangeles, Bruce A. HarmsAbstract:We tested the hypothesis that plasma Oncotic Pressure alone, not the plasma-to-lymph Oncotic Pressure difference, modulates pulmonary transvascular fluid filtration. To do this we measured lung lymph flow after raising left atrial Pressure (by inflating a balloon) in sheep that were receiving a continuous (32 h) infusion of dextran 40. For comparison, we also raised left atrial Pressure elevation, plasma Oncotic Pressures in dextran and control sheep, respectively, were 39.5 +/- 4.5 and 17.7 +/- 2.2 mm Hg; plasma-to-lymph Oncotic Pressure gradients, respectively, were 4.4 +/- 0.6 and 4.4 +/- 0.6 mm Hg. Left atrial Pressure elevation during dextran infusion increased lung lymph flow by a factor of 2.4 +/- 0.4, compared with a factor of 4.2 +/- 2.3 in control sheep. Thus, left atrial Pressure elevation increased lymph flow less in dextran-treated animals than in control animals, even though the plasma-to-lymph Oncotic Pressure gradients were equal. This suggests that plasma Oncotic Pressure alone may be a more important determinant of pulmonary transvascular fluid filtration than the plasma-to-lymph Oncotic Pressure difference.
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Effects of pentafraction and hetastarch plasma expansion on lung and soft tissue transvascular fluid filtration.
Surgery, 1995Co-Authors: Gregory A. Myers, Robert L. Conhaim, David J. Rosenfeld, Bruce A. HarmsAbstract:Background. Hetastarch and pentafraction are high molecular weight starch solutions designed to augment plasma Oncotic Pressure. Although clinical utilization of hetastarch has been limited by reported coagulation abnormalities, pentafraction is a newer derivative that appears to have few adverse hemostatic effects. We examined the ability of pentafraction to modulate lung and soft tissue transvascular fluid filtration under hypoproteinemic conditions compared with hetastarch and Ringer's lactate (LR). Methods. Awake, protein-depleted sheep (n=19) were prepared with lung and soft tissue lymph fistulas, and comparable infusions of 5% pentafraction (n=6), 6% hetastarch (n=6), or LR (n=7) were administered. Plasma and lymph samples were collected during 24-hour period to determine changes in protein concentrations, plasma-to-lymph Oncotic gradients, and lung (QL) and soft tissue (QS) lymph flows. Results. QL and QS rose nearly twofold after protein depletion alone. LR infusion increased QL and QS to 8.7±1.7 and 3.1±0.6 times normoproteinemic baseline, respectively (p Conclusions. Both hetastarch and pentafraction limit transvascular fluid filtration under hypoproteinemic conditions by augmenting plasma Oncotic Pressure and the plasma-to-lymph Oncotic Pressure gradient. Because of fewer adverse hemostatic effects pentafraction may be an improvement over current therapies in critical care fluid management.
Michael S. Garvey - One of the best experts on this subject based on the ideXlab platform.
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The Effect of Hetastarch on Serum Colloid Oncotic Pressure in Hypoalbuminemic Dogs
Journal of Veterinary Internal Medicine, 1996Co-Authors: Lisa E. Moore, Michael S. GarveyAbstract:The purpose of this study was to determine the duration of action of a single dose of hetastarch, a synthetic colloid, in hypoalbuminemic dogs. Thirty hypoalbuminemic dogs (albumin concentration, < or = 2.0 g/dL) received 1 dose of hetastarch each, with an average dose of 18.1 mL/kg. Doses ranged from 7.7 to 43.9 mL/kg, with the majority of doses (n = 26) in the range of 10 to 25 mL/kg. Dogs were allotted to one of several groups: all dogs, dogs with acute gastrointestinal protein loss, dogs with chronic gastrointestinal protein loss, all dogs with gastrointestinal protein loss, and dogs with nongastrointestinal protein loss. Colloid Oncotic Pressure was measured immediately before and immediately after hetastarch administration, and 12 hours after hetastarch administration. There was a significant (P < .001) increase in the mean colloid Oncotic Pressure after hetastarch treatment in all groups, except in the group with acute gastrointestinal protein loss. Twelve hours after hetastarch treatment, the mean colloid Oncotic Pressure had decreased significantly (P < .001) from the immediate post-treatment value in all groups, except in dogs in the groups with acute and chronic gastrointestinal protein loss. Twelve hours after hetastarch treatment the mean colloid Oncotic Pressure was not significantly (P < .001) different from the baseline mean colloid Oncotic Pressure in any of the groups. Twenty-three dogs (77%) survived their illness and were sent home, whereas, 7 (23%) died or were euthanized. The effect of a single dose of hetastarch on raising colloid Oncotic Pressure in dogs with hypoalbuminemia decreases significantly within 12 hours of administration, and is no longer significantly above baseline values. We conclude that multiple dosing is necessary to prolong the beneficial effects of hetastarch.
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The Use of Hetastarch as Adjunct Therapy in 26 Dogs With Hypoalbuminemia: A Phase Two Clinical Trial
Journal of Veterinary Internal Medicine, 1994Co-Authors: Laura E. Smiley, Michael S. GarveyAbstract:The purpose of this study was to evaluate the safety and efficacy of the synthetic colloid hetastarch in dogs with hypoalbuminemia. Individual doses of hetastarch ranged from 9 to 27 mL/kg, and multiple doses were used frequently. Total doses ranged from 9 to 59 mL/kg. Colloid Oncotic Pressure was measured in 13 dogs before and after treatment. Mean colloid Oncotic Pressure +/- SD was 9.32 +/- 2.35 mm Hg before treatment and 16.41 +/- 1.61 mm Hg in 8 healthy pet dogs used as controls. The difference in these values was significant (P < .001). There was a significant increase in mean colloid Oncotic Pressure after the first dose of hetastarch, but there was no relationship between the dose of hetastarch and the magnitude of increase in colloid Oncotic Pressure. Peripheral edema or body cavity transudates resolved or decreased in 83% of the dogs despite concurrent use of crystalloid fluid therapy. There was also no relationship between the dose of hetastarch and resolution of edema. Worsening of the results from coagulograms occurred in 5 of 18 dogs, and included increased prothrombin time (n = 1), increased partial thromboplastin time (n = 5), and decreased platelet count (n = 3). Bleeding that occurred in 3 dogs could not be directly attributed to the hetastarch. There was no relationship between the dose of hetastarch and worsening of the values in the coagulograms.
Sheldon Weinbaum - One of the best experts on this subject based on the ideXlab platform.
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Starling forces that oppose filtration after tissue Oncotic Pressure is increased
American journal of physiology. Heart and circulatory physiology, 2000Co-Authors: Roger H. Adamson, B. Liu, Fitz Roy E Curry, Sheldon WeinbaumAbstract:We tested the hypothesis that the effective Oncotic force that opposes fluid filtration across the microvessel wall is the local Oncotic Pressure difference across the endothelial surface glycocaly...
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The Starling forces that oppose filtration in the presence of tissue loading
Proceedings of the First Joint BMES EMBS Conference. 1999 IEEE Engineering in Medicine and Biology 21st Annual Conference and the 1999 Annual Fall Mee, 1Co-Authors: Sheldon Weinbaum, Roger H. Adamson, F. E. CurryAbstract:The net fluid flow across the capillary walls and the formation of lymph are governed by the imbalance of the hydrostatic Pressure and protein osmotic Pressure difference across the vessel wall. Contrary to the current interpretation of the Starling forces, we propose that the effective Oncotic force that opposes fluid filtration is the local Oncotic Pressure difference across the endothelial surface glycocalyx and not the global difference in Oncotic Pressure between the plasma and tissue as nearly universally assumed until now. Here we show, this local difference can differ greatly from the global Oncotic Pressure difference due to the presence of the junction strands which greatly inhibits back diffusion from the tissue space. This leads to a dramatic change in the fluid flux and a large reduction in current estimates of the filtration flow based on tissue Oncotic Pressure.
