Hepatic venular pressures of rats, dogs, and rabbits

1991 ◽  
Vol 261 (3) ◽  
pp. G539-G547 ◽  
Author(s):  
H. G. Bohlen ◽  
R. Maass-Moreno ◽  
C. F. Rothe

We tested the hypotheses that the hepatic venule pressures (Phv), just downstream from the hepatic sinusoids, are closely similar (less than 2 mmHg) either to the portal venous pressure (Ppv), indicating a high hepatic venous resistance, or to the inferior vena cava (Pivc) pressure, indicating a high portal-sinusoidal venous resistance, as reported by previous investigators. A micropipette servo-null pressure measurement technique was used with rats, dogs, and rabbits. Phv, referred to the anatomic level of the vena cava, averaged 5.1 +/- 1.0, 6.4 +/- 1.1, and 5.4 +/- 1.0 (SD) mmHg in the rats, puppies, and rabbits, respectively. Ppv averaged 8.0 +/- 1.4, 10.8 +/- 2.2, and 7.4 +/- 1.5 mmHg, respectively. Norepinephrine infusion into the portal vein (1-5 micrograms.min-1.kg-1) caused Ppv to increase and the portal venous flow to decrease but did not significantly affect Phv. The hepatic venous circuit contributed 44 +/- 17% (rats) and 31 +/- 26% (dogs) of the total liver venous vascular resistance under control conditions. We conclude that the portal and sinusoidal vasculatures are the dominant, but not exclusive, resistance sites of the liver venous vasculature both at rest and during norepinephrine-induced vasoconstriction.

Kanzo ◽  
1992 ◽  
Vol 33 (7) ◽  
pp. 531-540 ◽  
Author(s):  
Keiji TAICADA ◽  
Kenji NAKAMURA ◽  
Takao MANABE ◽  
Noriaki USUKI ◽  
Toshio KAMINOU ◽  
...  

2017 ◽  
Vol 313 (3) ◽  
pp. H676-H686 ◽  
Author(s):  
Bridget M. Seitz ◽  
Hakan S. Orer ◽  
Teresa Krieger-Burke ◽  
Emma S. Darios ◽  
Janice M. Thompson ◽  
...  

Serotonin [5-hydroxytryptamine (5-HT)] causes relaxation of the isolated superior mesenteric vein, a splanchnic blood vessel, through activation of the 5-HT7 receptor. As part of studies designed to identify the mechanism(s) through which chronic (≥24 h) infusion of 5-HT lowers blood pressure, we tested the hypothesis that 5-HT causes in vitro and in vivo splanchnic venodilation that is 5-HT7 receptor dependent. In tissue baths for measurement of isometric contraction, the portal vein and abdominal inferior vena cava relaxed to 5-HT and the 5-HT1/7 receptor agonist 5-carboxamidotryptamine; relaxation was abolished by the 5-HT7 receptor antagonist SB-269970. Western blot analyses showed that the abdominal inferior vena cava and portal vein express 5-HT7 receptor protein. In contrast, the thoracic vena cava, outside the splanchnic circulation, did not relax to serotonergic agonists and exhibited minimal expression of the 5-HT7 receptor. Male Sprague-Dawley rats with chronically implanted radiotelemetry transmitters underwent repeated ultrasound imaging of abdominal vessels. After baseline imaging, minipumps containing vehicle (saline) or 5-HT (25 μg·kg−1·min−1) were implanted. Twenty-four hours later, venous diameters were increased in rats with 5-HT-infusion (percent increase from baseline: superior mesenteric vein, 17.5 ± 1.9; portal vein, 17.7 ± 1.8; and abdominal inferior vena cava, 46.9 ± 8.0) while arterial pressure was decreased (~13 mmHg). Measures returned to baseline after infusion termination. In a separate group of animals, treatment with SB-269970 (3 mg/kg iv) prevented the splanchnic venodilation and fall in blood pressure during 24 h of 5-HT infusion. Thus, 5-HT causes 5-HT7 receptor-dependent splanchnic venous dilation associated with a fall in blood pressure. NEW & NOTEWORTHY This research is noteworthy because it combines and links, through the 5-HT7 receptor, an in vitro observation (venorelaxation) with in vivo events (venodilation and fall in blood pressure). This supports the idea that splanchnic venodilation plays a role in blood pressure regulation.


2019 ◽  
Vol 6 (5) ◽  
pp. 1947
Author(s):  
Mohd Kashif Ali ◽  
Eeman Naim

Background: Ultrasound guided fluid assessment in management of septic shock has come up as an adjunct to the current gold standard Central Venous Pressure monitoring. This study was designed to observe the respiro-phasic variation of IVC diameter (RV-IVCD) in invasively mechanically ventilated and spontaneously breathing paediatric patients of fluid refractory septic shock.Methods: This was a prospective observational study done at Paediatric intensive Care Unit (PICU) in Paediatric ward of Jawaharlal Nehru Medical College and Hospital (JNMCH) from February 2016 to June 2017. 107 consecutive patients between 1 year to 16 years age who were in shock despite 40ml/kg of fluid administration were included. Inferior Vena Cava (IVC) diameters were measured at end-expiration and end inspiration and the IVC collapsibility index was calculated. Simultaneously Central Venous Pressure (CVP) was recorded. Both values were obtained in ventilated and non-ventilated patients. Data was analysed to determine to look for the profile of RV-IVCD and CVP in ventilated and non-ventilated cases.Results: Out of 107 patients, 91 were on invasive mechanical ventilation and 16 patients were spontaneously breathing. There was a strong negative correlation between central venous pressure (CVP) and inferior vena cava collapsibility (RV-IVCD) in both spontaneously breathing (-0.810) and mechanically ventilated patients (-0.700). Negative correlation was significant in both study groups in CVP <8 mmHg and only in spontaneously breathing patients in CVP 8-12 mmHg range. IVC collapsibility showed a decreasing trend with rising CVP in both spontaneously breathing and mechanically ventilated patients.Conclusion: Ultrasonography guided IVCCI appears to be a valuable index in assessing fluid status in both spontaneously breathing and mechanically ventilated septic shock patients. However, more data is required from the paediatric population so as to define it as standard of practice.


2020 ◽  
Vol 5 (1) ◽  

Fluid therapy is an essential component part management of critically ill patients. Proper estimation of the amount of needed fluids is of great importance due to the well-established adverse effects of marked negative and positive fluids balance. Central venous pressure has been widely used by ICU physicians for volume status assessment. Several methods have been postulated for volume status assessment, among which is the inferior vena cava collapsibility index. As the inferior vena cava is a thin-walled capacitance vessel that adjusts to the body’s volume status by changing its diameter depending on the total body fluid volume. Giving the fact that bed-side ultrasonographic measurement of inferior vena cava diameters is an available, non-invasive, reproducible and quiet easy-to-learn technique, it can provide a safe and quiet reliable replacement of central venous pressure measurement for assessment of volume status assessment. The aim of this study was to find statistical correlation between central venous pressure and caval index, as a step towards validating the above mentioned replacement. 86 critically ill patients from ICU population were enrolled. Simultaneous measurements of central venous pressure and inferior vena cava collapsibility index were observed and recorded on four sessions. Patients were also grouped based on their mode of ventilation and central venous pressure values in order to compare the strength of correlation between various populations. The results showed that Inferior vena cava collapsibility index has significant inverse correlation with CVP value (r= -85, p value ˂0.001 at 95% CI) and it better correlated with mean arterial blood pressure and lactate clearance as compared to central venous pressure. However it correlated better with CVP in spontaneously breathing patients (r= -0.86, p value ˂0.001) than in mechanically ventilated patients (r= -0.84, p value ˂0.001). Inferior vena cava collapsibility index has shown to correlate better with CVP value in lower values (˂ 10 cmH2O) (r= -0.8, p value ˂0.001) than in higher values (≥ 10 cmH2O) (r= -0.6, p value ˂0.001). In addition, an inferior vena caval collapsibility index cut-off value of 29% was shown to discriminate between CVP values ˂10 cmH2O and values ≥10 cmH2O with high Sensitivity (88.6%) and specificity (80.4%). In conclusion, inferior vena cava collapsibility index has a strong inverse relationship with central venous pressure which is more pronounced at low central venous pressure values. Point-of-care ultrasonographically-measured inferior vena cava collapsibility index is very likely to be a good alternative to central venous pressure measurement with a high degree of precision and reproducibility. However, Wide scale studies are needed to validate its use in different patient populations.


2020 ◽  
Vol In Press (In Press) ◽  
Author(s):  
Ji-Chen Wang ◽  
Shi-Feng Cai ◽  
Chen Su ◽  
Hui-Li Fan ◽  
Yong-Hao Gai ◽  
...  

Background: Spontaneous portosystemic shunts (SPSS) are one of the hallmarks of Budd-Chiari syndrome (BCS). Ultrasound can accurately show the location and type of portosystemic collaterals. Objectives: To study the sonographic feature of SPSS in patients with BCS and to evaluate differences in the main portal vein diameter among multiple types of portosystemic shunts. Patients and Methods: Ultrasonographies of 44 patients with SPSS among 352 BCS patients between June 2000 and November 2015 were reviewed retrospectively. The SPSS in 44 BCS patients were first detected by ultrasound and then confirmed via digital subtraction angiography (DSA), computed tomography angiography (CTA) or magnetic resonance venography (MRV). The location, course, diameter and hemodynamics of the spontaneous portosystemic shunts were observed by ultrasound. In addition, one-way analysis of variance (ANOVA) was performed to evaluate the difference in the main portal vein diameter between the different shunt types. Results: The blood drainage patterns of SPSS in 44 of 352 patients with BCS were classified as the following five types: portal-umbilical shunts (15/44), portal-hepatic shunts (11/44), portal-accessory hepatic shunts (6/44) (the accessory hepatic veins included the inferior right hepatic vein and the caudate lobe vein), splenorenal shunts (8/44) and main portal vein-inferior vena cava shunts (4/44). The corresponding hemodynamics of the five types mentioned above were obtained. Main portal vein-inferior vena cava shunts had a significantly larger mean portal trunk diameter compared with all other types (P < 0.05 for all comparisons). In addition, the mean portal trunk diameters in portal-umbilical shunts and portal-hepatic shunts were obviously larger than that of splenorenal shunts (P < 0.05), while there were no statistically significant differences between the other types. Conclusion: Spontaneous portosystemic shunts are not rare in patients with BCS. Ultrasound is a reliable means for their diagnosis and it offers substantial information for use in clinical treatment.


1991 ◽  
Vol 15 (4) ◽  
pp. 585-588 ◽  
Author(s):  
Yoshitsugu Tsuda ◽  
Kazumasa Nishimura ◽  
Satoshi Kawakami ◽  
Isshu Kimura ◽  
Yoshihisa Nakano ◽  
...  

1994 ◽  
Vol 266 (5) ◽  
pp. E750-E759 ◽  
Author(s):  
J. Radziuk ◽  
S. Pye ◽  
D. E. Seigler ◽  
J. S. Skyler ◽  
R. Offord ◽  
...  

The absorption of a bolus of intraperitoneal insulin into the splanchnic and peripheral circulations was separately assessed in dogs using an infusion of two insulin tracers (A1-[3H]insulin and B1-[3H]insulin). One tracer was infused into the superior mesenteric artery and the second into the jugular vein. Serial samples were taken before and after an injection of insulin (1 U/kg ip). Sampling was from the portal vein and the inferior vena cava. By using the principle of equivalent entry of tracer and unlabeled material, we developed two simultaneous equations for the rate of splanchnic and peripheral insulin absorption at each time point. These were solved to yield the two rates. Mean concentrations in the portal vein were approximately 25% higher than in the inferior vena cava, reflecting the splanchnic absorption. This rate accounted for almost half (51 +/- 9%) of the insulin absorbed. The remainder of the absorption was peripheral. The total recovery of intraperitoneal insulin, absorbed by either route, was 88 +/- 11%. Portal absorption peaked earlier than peripheral. Absorption by both routes was 90% complete within approximately 2 h (131 +/- 16 min). In summary, therefore, intraperitoneal insulin is rapidly and almost completely absorbed, with absorption split between the splanchnic and peripheral routes of entry.


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