Effects of hemorrhage on umbilical venous return and oxygen delivery in fetal lambs

1982 ◽  
Vol 242 (4) ◽  
pp. H543-H548 ◽  
Author(s):  
J. Itskovitz ◽  
B. W. Goetzman ◽  
A. M. Rudolph

The effect of acute hemorrhage (21.7 +/- 1.6%, mean +/- SE of the estimated blood volume) on the distribution of the umbilical venous return (UVR) and oxygen delivery to fetal organs (radionuclide microsphere technique) was studied in 10 chronically catheterized fetal lambs. Hemorrhage decreased UVR and total oxygen delivery to the fetus by 23 and 28%, respectively (P less than 0.001). A greater proportion of the UVR bypassed the liver through the ductus venosus (DV) (P less than 0.01). Consequently, DV blood flow was relatively maintained, and liver blood flow and oxygen delivery derived from the UVR decreased by 41 and 45%, respectively (P less than 0.002). The proportion of cardiac output constituted by DV blood increased by 30% (P less than 0.01). The changes in the distribution of the DV blood were similar to the changes in the distribution of cardiac output. As a result the proportion of organ blood flow and oxygen delivery derived from DV blood increased by 30% in both the upper and lower body organs. These studies show that fetal hemorrhage has a marked effect on the distribution of the UVR to the liver. The preferential distribution of the DV blood to the heart and brain is maintained but not enhanced. Our results indicate that changes in distribution of the DV-derived blood and oxygen following fetal hemorrhage is determined primarily by the responses of the arterial circulation, i.e., circulatory afterload.

1992 ◽  
Vol 36 (6) ◽  
pp. 341
Author(s):  
P. ALTMAYER ◽  
U. GRUNDMANN ◽  
M. ZIEHMER ◽  
R. LARSEN ◽  
H. P. B??CH

1999 ◽  
Vol 277 (3) ◽  
pp. H1036-H1044 ◽  
Author(s):  
Shaolong Yang ◽  
Mian Zhou ◽  
Douglas J. Koo ◽  
Irshad H. Chaudry ◽  
Ping Wang

The cardiovascular response to sepsis includes an early, hyperdynamic phase followed by a late, hypodynamic phase. Although administration of pentoxifylline (PTX) produces beneficial effects in sepsis, it remains unknown whether this agent prevents the transition from the hyperdynamic to the hypodynamic response during the progression of sepsis. To study this, male adult rats were subjected to polymicrobial sepsis by cecal ligation and puncture (CLP). At 1 h after CLP, PTX (50 mg/kg body wt) or vehicle was infused intravenously over 30 min. At 20 h after CLP (i.e., the late stage of sepsis), cardiac output and organ blood flow were measured by radioactive microspheres. Systemic and regional (i.e., hepatic, intestinal, and renal) oxygen delivery (Do 2) and oxygen consumption (V˙o 2) were determined. Moreover, plasma levels of lactate and alanine aminotransferase (ALT) were measured, and histological examinations were performed. In additional animals, the necrotic cecum was excised at 20 h after CLP, and mortality was monitored for 10 days thereafter. The results indicate that cardiac output, organ blood flow, and systemic and regional Do 2decreased by 36–65% ( P < 0.05) at 20 h after CLP. Administration of PTX early after the onset of sepsis, however, prevented reduction in measured hemodynamic parameters and increased systemic and regional Do 2 andV˙o 2 by 50–264% ( P < 0.05). The elevated levels of lactate (by 173%, P < 0.05) and ALT (by 718%, P < 0.05), as well as the morphological alterations in the liver, small intestine, and kidneys during sepsis were attenuated by PTX treatment. In addition, PTX treatment decreased the mortality rate from 50 to 0% ( P < 0.05) after CLP and cecal excision. Because PTX prevents the occurrence of hypodynamic sepsis, this agent appears to be a useful adjunct for maintaining hemodynamic stability and preventing lethality from sepsis.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Stig Müller ◽  
Ole-Jakob How ◽  
Stig E Hermansen ◽  
Truls Myrmel

Arginin Vasopressin (AVP) is increasingly used to restore mean arterial pressure (MAP) in various circulatory shock states including cardiogenic shock. This is potentially deleterious since AVP is also known to reduce cardiac output by increasing vascular resistance. Aim: We hypothesized that restoring MAP by AVP improves vital organ blood flow in experimental acute cardiac failure. Methods: Cardiac output (CO) and arterial blood flow to the brain, heart, kidney and liver were measured in nine pigs by transit-time flow probes. Heart function and contractility were measured using left ventricular Pressure-Volume catheters. Catheters in central arteries and veins were used for pressure recordings and blood sampling. Left ventricular dysfunction was induced by intermittent coronary occlusions, inducing an 18 % reduction in cardiac output and a drop in MAP from 87 ± 3 to 67 ± 4 mmHg. Results: A low-dose therapeutic infusion of AVP (0.005 u/kg/min) restored MAP but further impaired systemic perfusion (CO and blood flow to the brain, heart and kidney reduced by 29, 18, 23 and 34 %, respectively). The reduced blood flow was due to a 2.0, 2.2, 1.9 and 2.1 fold increase in systemic, brain, heart and kidney specific vascular resistances, respectively. Contractility remained unaffected by AVP. The hypoperfusion induced by AVP was most likely responsible for observed elevated plasma lactate levels and an increased systemic oxygen extraction. Oxygen saturation in blood drawn from the great cardiac vein fell from 31 ± 1 to 22 ± 3 % dropping as low as 10 % in one pig. Finally, these effects were reversed forty minutes after weaning the pigs form the drug. Conclusion: The pronounced reduction in coronary blood flow point to a potentially deleterious effect in postoperative cardiac surgical patients and in patients with coronary heart disease. Also, this is the first study to report a reduced cerebral perfusion by AVP.


2007 ◽  
Vol 64 (3) ◽  
pp. 329-334 ◽  
Author(s):  
Mariska Y. M. Peeters ◽  
Leon P. H. J. Aarts ◽  
Ferenc A. Boom ◽  
Leo J. Bras ◽  
Dick Tibboel ◽  
...  

1995 ◽  
Vol 152 (2) ◽  
pp. 511-518 ◽  
Author(s):  
N Brienza ◽  
T Ayuse ◽  
C P O'Donnell ◽  
S Permutt ◽  
J L Robotham

1987 ◽  
Vol 252 (5) ◽  
pp. H894-H899 ◽  
Author(s):  
Y. W. Chien ◽  
E. D. Frohlich ◽  
N. C. Trippodo

To examine mechanisms by which administration of atrial natriuretic peptide (ANP) decreases venous return, we compared the hemodynamic effects of ANP (0.5 microgram X min-1 X kg-1), furosemide (FU, 10 micrograms X min-1 X kg-1), and hexamethonium (HEX, 0.5 mg X min-1 X kg-1) with those of vehicle (VE) in anesthetized rats. Compared with VE, ANP reduced mean arterial pressure (106 +/- 4 vs. 92 +/- 3 mmHg; P less than 0.05), central venous pressure (0.3 +/- 0.3 vs. -0.7 +/- 0.2 mmHg; P less than 0.01), and cardiac index (215 +/- 12 vs. 174 +/- 10 ml X min-1 X kg-1; P less than 0.05) and increased calculated resistance to venous return (32 +/- 3 vs. 42 +/- 2 mmHg X ml-1 X min X g; P less than 0.01). Mean circulatory filling pressure, distribution of blood flow between splanchnic organs and skeletal muscles, and total peripheral resistance remained unchanged. FU increased urine output similar to that of ANP, yet produced no hemodynamic changes, dissociating diuresis, and decreased cardiac output. HEX lowered arterial pressure through a reduction in total peripheral resistance without altering cardiac output or resistance to venous return. The results confirm previous findings that ANP decreases cardiac output through a reduction in venous return and suggest that this results partly from increased resistance to venous return and not from venodilation or redistribution of blood flow.


1987 ◽  
Vol 117 (8) ◽  
pp. 1469-1474 ◽  
Author(s):  
Tammy M. Sakanashi ◽  
Heather E. Brigham ◽  
Kathleen M. Rasmussen

1963 ◽  
Vol 204 (2) ◽  
pp. 301-303 ◽  
Author(s):  
L. Takács ◽  
V. Vajda

The effects of intraperitoneal and intravenous administration of serotonin on cardiac output, blood pressure, and organ distribution of blood flow (Rb86) were studied in the rat. Fifteen to thirty minutes after intraperitoneal injection (10 mg/kg) cardiac output was unchanged, while blood pressure was significantly reduced. Increase in blood flow was noted in the myocardium, pulmonary parenchyma and "carcass" (skeletal muscle, bone, CNS), with decrease in the kidney and the skin. Splanchnic blood flow was unchanged. Conversely, intravenous infusion of serotonin produced an increase of cardiac output, blood pressure, and cutaneous blood flow.


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