Assessment Of Systemic Hemodynamics Research Articles

The role of the main hemodynamic parameters assessing in modern experimental practice

We report an analysis of published data concerning the measurement of systemic hemodynamic parameters in experiments on laboratory animals. The article highlights the influence of such issues as housing and husbandry, handling, the frequency of person contact, animal surgical modification and pharmacological support in the perioperative period on blood pressure and heart rate, the most frequently recorded parameters both in experiment and clinic. Published data should be taken into account when planning and preparing an experiment using biomedical animal models, as well as when developing and submitting a protocol to the bioethical commission. Assessment of systemic hemodynamics is an integral part of physiological monitoring in any surgery of animals allowing better standardization of experimental endpoints and timely correction of possible deviations.

Effects of vasopressin during a pulmonary hypertensive crisis induced by acute hypoxia in a rat model of pulmonary hypertension

BackgroundA pulmonary hypertensive crisis (PHC) can be a life-threatening condition. We established a PHC model by exposing rats with monocrotaline (MCT)-induced pulmonary hypertension to acute hypoxia, and investigated the effects of vasopressin, phenylephrine, and norepinephrine on the PHC. MethodsFour weeks after MCT 60 mg kg−1 administration i.v., right ventricular systolic pressure (RVSP), systolic BP (SBP), mean BP (MBP), cardiac index (CI), and pulmonary vascular resistance index (PVRI) were measured. PHC defined as an RVSP exceeding or equal to SBP was induced by changing the fraction of inspiratory oxygen to 0.1. Rats were subsequently treated by vasopressin, phenylephrine, or norepinephrine, followed by assessment of systemic haemodynamics, isometric tension of femoral and pulmonary arteries, cardiac function, blood gas composition, and survival. ResultsPHC was associated with increased RV dilatation and paradoxical septal motion. Vasopressin increased MBP [mean (standard error)] from 52.6 (3.8) to 125.0 (8.9) mm Hg and CI from 25.4 (2.3) to 40.6 (1.8) ml min−1 100 g−1 while decreasing PVRI. Vasopressin also improved RV dilatation, oxygenation, and survival in PHC. In contrast, phenylephrine increased MBP from 54.8 (2.3) to 96.8 (3.2) mm Hg without improving cardiac pump function. Norepinephrine did not alter MBP. Vasopressin contracted femoral but not pulmonary arteries, whereas phenylephrine contracted both arterial beds. Hence, improvements with vasopressin in PHC might be associated with decreased PVRI and selective systemic vasoconstriction. ConclusionsIn this rat model of a PHC, vasopressin, but not phenylephrine or norepinephrine, resulted in better haemodynamic and vascular recovery.

Non-invasive Diagnosis of Oesophageal Varices Using Systemic Haemodynamic Measurements by Finometry: Comparison with Other Non-invasive Predictive Scores

Cirrhosis and portal hypertension are characterised by a hyperdynamic circulation, which is independently associated with variceal size. Non-invasive techniques for measurement of systemic haemodynamics are now available. The aim of the study was to prospectively assess the accuracy of systemic haemodynamics measured non-invasively for the detection of oesophageal varices in cirrhotic patients as compared to other currently available non-invasive methods. In a study of 29 cirrhotic patients, systemic haemodynamics were studied non-invasively using the Finometer® (mean arterial pressure (MAP), cardiac output (CO)/index, heart rate (HR), peripheral vascular resistance) and portal pressure was assessed by hepatic venous pressure gradient. Sensitivity, specificity, predictive values and area under the receiver operating characteristic (ROC) curves were assessed for predicting presence of varices and large oesophageal varices. Results were compared to child's classification, platelet/spleen ratio and ALT/AST ratios as predictors of the presence of large varices. Using finometry large oesophageal varices were correctly predicted in 83% of patients compared to other non-invasive techniques (range 66-76%). Non-invasive assessment of systemic haemodynamics using finometry could aid the identification of patients who do not immediately require variceal surveillance reducing the numbers of endoscopies and ensuring services are provided to those most likely to benefit.

FEATURES OF PREOPERATIVE PREPARATION OF PATIENTS WITH DIFFERENT FORMS OF CLINICAL COURSE OF PHEOCHROMOCYTOMA

A comparative analysis of subjective and objective criterion was made in order to evaluate efficacy of preoperative preparation in 101 patients with pheochromocytoma of different clinical course. It was shown the reasonability of monitoring usage of noninvasive method of assessment of systemic hemodynamics (bio-impedance reo-vasography and daily monitoring of arterial pressure) for evaluation of preoperative preparation adequacy. The need of differentiated approach and strategy of preoperative preparation were based on clinical course of pheochromocytoma.

Esophageal Varices: Pathophysiology, Approach, and Clinical Dilemmas

Esophageal Varices: Pathophysiology, Approach, and Clinical Dilemmas

Elevated plasma levels of urotensin II do not correlate with systemic haemodynamics in patients with cirrhosis

Background The hyperdynamic circulation of hepatic cirrhosis is related to decreased systemic vascular resistance due to arterial vasodilation. Urotensin II plasma levels are increased in cirrhotic patients, and have been suggested to play a role in the pathogenesis of systemic haemodynamic alterations. Aim To evaluate the relationships between systemic haemodynamics and urotensin II plasma levels. Methods Thirty-six consecutive in-patients with cirrhosis and no alteration of plasma creatinine, and 20 age- and gender-matched healthy volunteers underwent noninvasive assessment of systemic haemodynamics and measurement of urotensin II plasma levels. Results In comparison to healthy controls, cirrhotic patients had signs of hyperdynamic circulation and higher plasma urotensin II levels. Plasma urotensin II was neither significantly different amongst patients with different severity of cirrhosis nor between patients with or without ascites. Both in controls and cirrhotic patients no significant correlations were found between parameters of systemic haemodynamics and plasma urotensin II levels. Conclusions In patients with cirrhosis and hyperdynamic circulation, but with normal serum creatinine, urotensin II is higher than in healthy subjects. However, no correlation with cardiac index or other haemodynamic parameters was observed, indicating that other mechanisms prevail.

P16 Non-invasive detection of oesophageal varices: comparison of non-invasive assessment of systemic haemodynamics with laboratory parameters and predictive scores

IntroductionEndoscopic screening for varices (OV) is advised in cirrhosis, repeated every 1–3 years, with primary prophylaxis given to large OV. This is costly to endoscopy units, unpleasant for patients and...

PTU-065 Non-invasive assessment of systemic haemodynamics to determine oesophageal variceal size in cirrhotic patients: Abstract PTU-065

Introduction Portal pressure underlies variceal development, bleeding and mortality but is not routinely assessed. Universal endoscopic screening is advised in cirrhosis with primary prophylaxis given if varices >5 mm diameter. This is labour intensive and costly, but non-invasive predictors of varices are unreliable. Cirrhosis is associated with a hyperdynamic circulation and quick, easy, non-invasive assessment of this is now possible. The aim of this study was to evaluate whether non-invasive assessment of systemic haemodynamics in cirrhosis can identify patients with significant oesophageal varices. Methods We studied 29 cirrhotic patients. Systemic haemodynamics were assessed non-invasively using the Finometer® (TNO instruments, Amsterdam), and analysed with Beatscope® software. Portal pressure was assessed by measurement of the hepatic venous pressure gradient (HVPG). Gastroscopy assessed variceal size, Japanese score and 1-year probability of bleeding according to the NIEC index. Results 69% male, median age 47 (42–55) years, Child-Pugh (CP) score 6 (Class A 18, Class B 10, Class C 1) and MELD 10 (8–13). 90% alcoholic cirrhosis, 66% abstinent. HVPG positively correlated with CP score (r=0.58, p=0.001), cardiac index (r=0.53, p=0.005) and heart rate (r=0.62, p Conclusion Non-invasive assessment of systemic haemodynamics in cirrhosis identifies the hyperdynamic circulation and can distinguish between absent/small and medium/large sized varices. This technique appears promising as a tool to help identify a group of patients who would most benefit from endoscopic screening and primary prophylaxis.

PTU-066 Non-invasive assessment of systemic haemodynamics to determine variceal bleeding risk in cirrhotic patients: Abstract PTU-066

Introduction Variceal bleeding is one of the most severe complications of portal hypertension. Universal endoscopic variceal screening is recommended and primary prophylaxis given based on oesophageal variceal size. Risk of bleeding also relates to other factors such as portal pressure, liver disease severity, and red wale markings at endoscopy. Currently there is no non-invasive way of measuring portal pressure or bleeding risk. The aim of this study was to evaluate whether non-invasive assessment of systemic haemodynamics in cirrhosis can identify bleeding risk in portal hypertension. Methods We studied 29 cirrhotic patients. Systemic haemodynamics and baroreceptor sensitivity (BRS) were assessed non-invasively using the Finometer® (TNO instruments, Amsterdam), and analysed with Beatscope® software. Spontaneous BRS was assessed by studying the relationship between inter-beat variability and beat-to-beat changes in systolic blood pressure. Portal pressure was assessed by measurement of the hepatic venous pressure gradient (HVPG). Gastroscopy assessed variceal size, Japanese score and 1-year probability of bleeding according to the NIEC index. Results 69% male, median age 47 (42–55) years, Child-Pugh (CP) score 6 (Class A 18, Class B 10, Class C 1) and MELD 10 (8–13). 90% alcoholic cirrhosis, 66% abstinent. HVPG correlated positively with variceal size (r=0.64, p Conclusion Non-invasive assessment of systemic haemodynamics in cirrhosis may be useful in predicting HVPG and bleeding risk from oesophageal varices. This study highlights that other factors such as baroreceptor sensitivity are important in determining portal pressure and bleeding risk and may open up potential new treatment options.

Transthoracic electrical bioimpedance: A non-invasive technique for the evaluation of the haemodynamic alterations in patients with liver cirrhosis

Background/aim. Transthoracic electrical bioimpedance is a non-invasive technique for the evaluation of systemic haemodynamics. Compared to Doppler ultrasound, it has the advantage of being operator-independent, providing continuous monitoring and being less influenced by postural changes. Until now, transthoracic electrical bioimpedance has been applied to a very limited extent in liver cirrhosis. We, therefore, aimed to compare transthoracic electrical bioimpedance and echocardiography in the assessment of haemodynamic status in cirrhotic patients. Patients/methods. Thirteen patients with compensated cirrhosis, 10 patients with cirrhosis and ascites and 12 controls were enrolled. Haemodynamic parameters (stroke volume, cardiac output, heart rate, mean arterial pressure and vascular peripheral resistance) were assessed simultaneously by transthoracic electrical bioimpedance monitoring with BioZ.com™ for at least 10 min and Doppler ultrasound. Results. The absolute mean values of haemodynamic parameters obtained by the two techniques were quite similar in all groups; furthermore, a good agreement between transthoracic electrical bioimpedance and echocardiography measurements was found for all the parameters. Finally, transthoracic electrical bioimpedance proved easy to employ and provided continuous real-time monitoring of cardio-circulatory variations. Conclusions. The present study showed a significant correlation between transthoracic electrical bioimpedance and echocardiography in the assessment of systemic haemodynamics in patients with cirrhosis, supporting the employment of transthoracic electrical bioimpedance in pathophysiological studies requiring real-time continuous monitoring of haemodynamic parameters.

Vascular reserve in the lower limbs of cirrhotic patients: a duplex Doppler ultrasound study

Aim. To evaluate femoral artery impedance at rest and during reactive hyperaemia. Patients. Study population comprised 11 cirrhotic patients without ascites, 10 with ascites and 16 age- and sex-matched healthy subjects. Methods. Echocardiographic assessment of systemic haemodynamics; duplex Doppler ultrasound measurement of femoral artery pulsatility index and vascular reserve (pulsatility index rest/pulsatility index hyperaemia). Results. Cirrhotic patients had elevated cardiac index and low systemic vascular resistance. Pulsatility index (right femoral artery) was not statistically different either at rest or after reactive hyperaemia (controls: rest 1 D. 6±0. 4, hyperaemia 2. 6±0. 2; compensated cirrhosis: rest 10. 1±0.8, hyperaemia 3.4±0.4; ascitic cirrhosis: rest 11.4±1.6, hyperaemia 2.9±0.4. Vascular reserve was 4.38±0.35 in controls, 3.33±0.39 in compensated and 4.70±0.89 in ascitic cirrhosis (p = not significant). No correlation was found between systemic haemodynamic parameters and either pulsatility index or vascular reserve. Conclusions. The lower limb vascular reserve is preserved in cirrhosis.