Gerald Castor – France

PITFALLS OF THE PULMONARY ARTERY CATHETER: A NEVER ENDING STORY

Karel Cvachovec - Czech Republic

MULTIPLE ORGANS DYSFUNCTION SYNDROME: ITS ORIGIN, PROGRESS AND HEMODYNAMIC PATTERN

Basrul Hanafi – Indonesia

HYDROXY ETHYL STARCH SOLUTION IN PERIOPERATIVE FLUID RESUSCITATION OG HEMORRHAGIC SHOCK DUE TO BLUNT ABDOMINAL INJURY

Basrul Hanafi – Indonesia

TIME INTERVAL IN REACHING THERAPEUTIC GOAL IN HEMORRHAGIC SHOCK DUE TO BLUNT ABDOMINAL SURGERY

Jozef Kollar, P. Daxner, J. Koprovicova, D. Petraskova

ANTIOXIDATIVE DEFENCE STATUS OF ADULTS IN EAST SLOVAKIA

Atila Korkmaz, Muhittin Alkis, E. Okan Hamamci, Nilufer Erverdi, Hasan Besim

HEMODYNAMIC CHANGES DURING GASEOUS AND GASLESS LAPAROSCOPIC CHOLECYSTECTOMY

Jan Musil, Josef Prazak, David Leitermann - Czech Republic

SOME COMPLEMENTING ASPECTS TO THE MECHANICALLY ASSISTED HEAR FAILURE

Karel Pitr, Jaroslav Prucha, Jan Zabran, Jan Zahlava

VACUUM-COMPRESSION THERAPY: HAEMODYNAMIC THERAPEUTIC-REHABILITATION METHOD IN THE LIGHT OF FIVE YEARS OF RESEARCH AND EXPERIENCE

Svetlana Prevorovska, Jan Musil, Frantisek Marsik - Czech Republic

CARDIOVASCULAR HEMODYNAMICS DURING HEMORRHAGING (A NUMERICAL MODEL)

Ire Sri Redjeki – Indonesia

HEMODYNAMIC PROFILE OF PATIENTS UNDERGOING LAPAROSCOPIC SURGERY

Reno Rudiman – Indonesia

PHYSIOLOGIC PATTERNS AND RESPONSES OF THERAPY ON SYSTEMIC, REGIONAL CIRCULATION, END ORGAN FUNCTIONS IN GENERAL PERITONITIS DUE TO TYPHOID ILEAL PERFORATION

J. Lukac, M. Sitar, L. Adamovic, J. Celko – Slovakia

HEMODYNAMICS OF THE CAD DURING SULPHUROUS WARM-WATER BATH

B. Bo Sramek – USA

SYSTEMIC HEMODYNAMICS: FICTIONS AND FACTS

B. Bo Sramek – USA

INTRODUCTION TO BEAT HEMODYNAMICS AND OXYGEN TRANSPORT DYNAMICS AND TO HEMODYNAMIC MANAGEMENT

J.A. Tichy, M. Loucka, J. Svacinka, Z. Trefny, M. Hojerova – Czech Republic

ANALYSIS OF SIMULTANEOUSLY ESTIMATED DATA BY TEB (THORACIC ELECTRICAL BIOIMPEDANCE) AND PDD (PULSE DYE DENSITOMETRY)

Dita Valerianova – Czech Republic

AORTIC ELASTICITY UNDER PULSATILE FLOW – IN VITRO EXPERIMENTAL STUDY

After decades of enthusiasm for invasive monitoring, disillusionment has become a reality about the possibilities to change the outcomes of critically ill patients by means of the pulmonary artery catheter (PAC). Beside the theoretical and practical problems, many complications are described with consecutive unnecessary morbidities and mortalities after use of these catheters [1,2].

At the beginning, the PACs were not critically evaluated under strict protocols. However, they quickly became the so-called "golden standard". Although the PACs are now in use for more than twenty years, few practitioners understand the principles and above all the technical problems and limitations of the PAC-monitoring.

In a multicenter-study [3] it was proved that clinicians using PA-catheters have no acceptable level of knowledge regarding these catheters. So eventual benefits of a PA-catheter will be small, until there is a greater user competency. The problems and limitations of the PAC will be explained in this presentation.

References:
[1] Gore JM, Goldberg RJ, Spodick DH, Alpert JS, Dalen JE. A community-wide assessment of the use of pulmonary artery catheters in patients with acute myocardial infarction. Chest 1987;92:721-727

[2] Robin ED. Death by pulmonary flow directed catheter. Chest 1987;92727-731

[3] Iberty TJ, Fischer EP, Leibowitz AB, Panacek EA, Silverstein JH, Albertson TE. A multicenter study of physicians knowledge of the pulmonary artery catheter. Pulmonary artery catheter study group. JAMA 1990;264:2928-2932

Multiple organ dysfunction syndrome (MODS) has been defined as a presence of such altered organ function in acutely ill patients that homeostasis can not be maintained without intervention(1). It is a dynamic, evolving clinical syndrome characterized by the development of otherwise unexplained ab-normalities of organ function. Available evidence suggests that in the majority of cases the MODS is a result of uncontrolled inflammation and it is more frequently a consequence of sequential, repeated in-sults rather than a result of a single, massive impact. Although the syndrome has been described more than two decades ago and despite the progress in its understanding and in the availability of the methods for treating critically ill patients, its mortality has not changed appreciably since. It remains a major un-solved clinical problem and it is a leading cause of death of the patients admitted to the ICU(2). Its asso-ciation, either direct or undirect, with sepsis or with systemic inflammatory response syndrome (SIRS), seems to be undisputed. The severity of sepsis or SIRS (i. e., the presence of shock) correlates well with later mortality(3).

Several hypotheses were offered to explain the development of MODS: the macrophage/media-tor hypothesis postulates that an excessive or prolonged stimulation of macrophages leads to the overpro-duction of proinflammatory cytokines, stimulating in turn the production of secondary mediators, which activate neutrophils and endothelial cells perpetuating tissue injury. Another hypothesis proposes that or-gan injury be related to ischemia and/or endothelial injury during reperfusion. The gut-origin hypothesis blames the loss of gut mucosal-barrier function(2). Recent hypothesis considers organ systems as a bio-logical oscillators orderly coupled by communications network consisting of neural, humoral a cytokine components. Progressive uncoupling that can become irreversible is initiated by SIRS and can be re-flected in the development of MODS(4). Although the circulatory pattern of sepsis, SIRS or the develop-ing MODS can be described in the terms of pressures, flow and its changes over the time it seems that consistent circulatory pattern in survivors is increased cardiac index and increased oxygen delivery(5). Ominous circulatory pattern includes intractable systemic hypotension, depressed ventricular function (both contractility and relaxation), heterogeneity of O2 delivery and impaired O2 extraction(6).

References:
1. Bone RC et al. Chest 101, 1992: 1644 - 1655.
2. Livingston DH, Mosenthal AC, Deitch EA New Horizons 3, 1995: 257 - 266.
3. Muckart DJJ, Bhagwanjee S Crit Care Med 25, 1997: 1789 - 1795.
4. Godin PJ, Buchman TG Crit Care Med 24, 1996: 1107 - 1116
5. Shoemaker WC New Horizons 4, 1996: 300 - 318.
6. Walley KR, pp. 243 - 255 In: 1997 Yearbook of Intensive Care and emergency Medicine, Springer,
Berlin 1997.

Key words:
critical care, multiple organ dysfunction, systemic inflammatory response syndrome, shock, sepsis

Blunt abdominal injury frequently leads to massive blood loss and severe haemorrhagic shock. Fluid replacement therapy with crystalloid solution and blood transfusion are indicated as the standard fluid resuscitation under such conditions. However, blood is not always available in certain circumstances and with the increasing risk of HIV infections, colloid solutions, such as Hydroxy Ethyl Starch Solution, becomes a sensible alternative. To know the effect of Hydroxy Ethyl Starch Solution on hemodynamic and hemorrheologic conditions, oxygen transport variables, and organ functions in the use for perioperative fluid resuscitation in haemorrhagic shock, we conducted a quasi-experimental study to analyze its effect during pre-, intra- and post-operative periods.

Ten patients, who were admitted to Hasan Sadikin Hospital, Bandung, with haemorrhagic shock due to blunt abdominal injury, were included in this study. The degree of shock was classified using ATLS guidelines. Hydroxy Ethyl Starch 10% solution was administered for fluid resuscitation in accordance with the degree of shock. In class III and IV of shock, blood transfusions, either PRC or combination of PRC and FFP were also administered as required. Hemodynamic changes and oxygen transport variables were measured by non-invasive monitoring, whereas renal functions were evaluated by urine output and serum levels of urea and creatinine. In all patients Hydroxy Ethyl Starch 10 % solution administration showed significant improvement of Oxygen Delivery, Cardiac Output, Cardiac Index, and Volume status after resuscitation. No renal failure was observed in any of these cases. The number of blood units required decreased during the resuscitation period.

In conclusion, the use of Hydroxy Ethyl Starch Solution 10 % for fluid resuscitation in patients with hemorrhagic shock due to blunt abdominal injury achieved satisfactory improvement of hemodynamic, oxygen transport and renal function. The increasing use of HAES 10 % may reduce the need of blood transfusion in hemorrhagic shock due to blunt abdominal trauma. Further studies are needed to evaluate the significance of such results.

Keywords:
Hemorrhagic Shock, Fluid Resuscitation, Hydroxy Ethyl Starch Solution.

Trauma is one of the most common causes of deaths in young adult Indonesians. The usual cause of death in trauma is inadequate resuscitation in severe hemorrhagic shock. Controversy exists in terms of how fast should the fluid resuscitation given to treat the shock. It has been shown that acute resuscitation in animal experiments causes the release of certain mediators (IL-6, TNF-a, etc), significant increase of nitrite-oxide, and plasma xanthine oxidase, leading to hemodynamic impairment including decreased microvascular perfusion. Hayes (1993) has shown that there is a 24-hour window of safety in the speed of fluid resuscitation which correlates significantly with mortality. We conducted a study to reveal the correlation of speed of fluid resuscitation in reaching therapeutic goal with its impact in renal perfusion.

Patients with severe hemorrhagic shock due to blunt abdominal trauma were randomized into two groups. In the first group, the patients were resuscitated rigorously so that they reached therapeutic goal, as measured with HOTMANä System (HEMO SAPIENSâ INC, Sedona, AZ, USA), within 12 hours. In the second group, therapeutic goal is reached within 24 hours. Hemodynamic parameters were recorded, as well as serum creatinine, rapid creatinine clearance, and diuresis.

After three days of follow up, patients in the second group showed a better renal perfusion compared to the first group.

In conclusion, time interval of 24 hours to reach therapeutic goal in resuscitation of hemorrhagic shock results in better renal perfusion in comparison to acute 12 hours resuscitation. Reperfusion injury may play a role in this phenomenon. Further trial is needed to look upon the difference within cellular level.

Keywords:
trauma, fluid resuscitation,

Introduction.

Slovak Republic exhibits very high mortality rates from cardiovascular diseases. Up to now, in an attempt to explain this incriminating phenomenon, the high incidence of known major risk factors was used. However, as we have found out, the causality figures were oversimplified, because some other very im-portant risk factors, i.e., the antioxidative efficacy, were not included.

Methods.

Based upon this finding, a decision was made to check the antioxidative status of a large population sam-ple of adults {1,125 subjects, 62% men/38% women, mean age 41 years}. The antioxidative status was studied through the use of standard determinates methods.

Results.

Serum concentration of vitamin C was significantly below the standard levels {p<0,01} mainly in men, in smokers and in hyperlipidemic subjects and was critical in subjects with acute coronary events. Serum level of retinol was not decreased. Serum levels of vitamin E were significantly lower, with the exception of the subjects with hyperlipidaemia. Index value of total cholesterol/vitamin E, LDL-CH/vitamin E showed reduced levels of vitamin also in adults with hyperlipidaemia. From the proteins of acute inflam-mation phase with antioxidative function, the levels of transferin were not changed, but the levels of cae-ruloplasmine were significantly decreased {p<0,05}. Plasma levels of malondialdehyde were significantly increased {p<0,01}. Level of superoxide dismutase and catalase were significantly lower {p<0,01}.

Discussion.

Based on these results, we may stipulate that major risk profile must include the antioxidative protection of organism, since we have identified it as a major risk-contributing factor. It is only natural that in a Slo-vak population oriented preferentially on consumption of saturated fats with a high proportion of meat and low intake of fruits and vegetables, the high incidence of cardiovascular diseases must be associated with the deficit in natural antioxidative defense.

Conclusion.

High mortality on coronary atherosclerosis in our country may be explained by a low status in antioxida-tive protection. Lack of antioxidative protection should be added to the list of serious risk factors in coro-nary atherosclerosis.

Key Words:
Antioxidative status, defense, protection, hyperlipidaemia, atherosclerosis

The aim of the present study is to investigate the hemodynamic effects of the pneumoperitoneum and the comparison of gasless and gaseous laparoscopic cholecystectomy on a hemodynamical basis.

The main disadvantage of the gaseous laparoscopic technique is carbon dioxide insufflation and the elevation of intraabdominal pressure.

Gasless laparoscopic technique is an alternative to gaseous laparoscopic surgery to prevent from the hazardous effects of pneumoperitoneum. In this procedure, an electromechanical retractor system is used to lift the abdominal wall.

20 gaseous and 11 gasless laparoscopic cholecystectomies were performed in 31 patients with symptomatic gallstones. Mean arterial pressure (MAP), heart rate (HR), end diastolic index (EDI), sys-temic vascular resistance index (SVRI), cardiac index (CI), ejection fraction (EF) and stroke index (SI) values were monitored by thoracic electrical bioimpedence (TEB); a non-invasive technique. In the gase-ous group, statistically significant changes were detected in MAP, SVRI, CI, EF, and SI values after in-sufflation when compared to the values before pneumoperitoneum. In the gasless group only minimal changes could be detected in the EDI, SVRI and SI values which were statistically insignificant. SVRI, EDI and CI differences were statistically significant when compared between the two groups.

In conclusion gasless laparoscopy has little effect on the hemodynamical parameters of patients and it is an alternative to the gaseous technique in selected cases.

Haemodynamic state of patients was evaluated by means of dichromatic auricular densitometry (cardiac output computer in connection with line recorder TZ 4100) and simultaneous measurements by the CDDP (cardiodynamic data proceeding) System. Haemodynamic parameters were estimated not only by incorpo-rated equations but also with regard to dynamic changes of ECG, bioimpedance signals, pulse waves, me-chanical acceleration signals and blood dye concentrations.

According to Japanese reports e.g. t. Iijima (nostril piece) or others, the obtained values in comparison to direct spectrometry are supposedly lower. Our method of minimal three direct determination of ICG (in-docyanin green) plasma concentration excludes these differences.

Analysis of ICG curves (first pass dilution) and their late face of disappearance by hepatic uptake are valuable in all cases, which is not possible with the CDDP System. Thoracic bioimpedance is not usable in case of cardiac pacing and in patients with left bundle branch block.

The data obtained by both methods are in good agreement with each other.

Most hepatopathy cases are accompanied with hyperdynamic state, related to elevated circulation of blood volume.

We present the new method of ICG curve analysis for a valuable study of liver diseases.


Key Words: dye dilution, bioimpedance methods, correlation of haemodynamic parameters,
ICG uptake, studying of liver diseases.

Heart failure managed by mechanical support devices, e.g. rotary blood pump, has become nearly a routine method used, provided pharmacotherapy failed. Both acute and/or chronic heart failure reflects hemodynamically the pathophysiology of the latter ominous clinical syndrome.

Mechanical support using one centrifugal rotary pump applied to the pulsating ventricle, simu-lating left ventricular failure on the mock line circuit, was investigated.

Two limiting states characterizing the dynamic effectiveness of the rotary pump were determined. Furthermore, the consequences of the systemic compliance changes in the mentioned circuit were fol-lowed up and evaluated.
Both phenomena complemented the view on the dynamics of the mechanically assisted heart fail-ure (in vitro) and accordingly might be taken into account provided this procedure be clinically applied.

Key words: heart failure, mechanical assistance, rotary pump, limiting states, systemic compliance

Physiotherapy offers a very effective hemodynamic method called vacuum-compression therapy (VCT), especially in the fields of therapeutic rehabilitation, angiology, and diabetology. Up to now, insufficient expansion of this perspective method falls to the debit of insufficient clarification of principles of VCT and practical possibilities of its use. The new generation of devices (EXTREMITER 2000 and 2010) enabled to motivate this method experimentally and to obtain enough experience to write this expertise. Verification of therapeutic effects of VCT in the treatment of peripheral arterial circulatory disorders, stagnation metabolisms, impaired trophic and post-traumatic stress states of the extremities, is based on use of radionuclide and remission-spectroscopic methods and numerous cases of successfully treated patients.

Vacuum-compression therapy is a physical therapeutic method used primarily for effective therapy of hemodynamic peripheral circulatory disorders of extremities and their stagnated metabolisms and trophic of different etiopathogenesy. Therapy is based on the alteration of underpressure and overpressure phases. In the dominant underpressure phase, deep hyperaemia appears, in the overpressure phase an increased volume of blood is forced through the veins.

The influence of the hypobaric environment upon the treated extremity is the basic factor of comprehensively acting vacuum-compression therapy. The aim is to induce a local passive hyperaemia from the maximum open collateral bed. The results of a five-year practice and goal-directed experiments presented in this expertise show the degree of this aim and conditions for their achievement.

Monitoring of changes in perfusion has showed that VCT is able to increase overall perfusion of the extremity (left lower extremity in our case) in a vacuum stage of the procedure by 3 times, but in an overpressure (elimination) stage of the procedure the perfusion remains roughly 2 times higher in comparison with the non-influenced contrallateral extremity (right lower extremity).

The second group of experiments is based on remission-spectrophotometric measurements. This is based on a characteristic spectrum of haemoglobin as given by spectral analysis in an initial state (before the experiment). This spectrum graphically demonstrates the possibility of a detailed non-invasive measurement of vascular functions.

It is shown that VCT improves perfusion in the area of deep structures (large vessels and capillary blood in muscles, in particular). This has been proved by experiments with erythrocytes marked with radionuclide technetium. With this effect, VCT on principle exceeds effects of lumbal sympatikotomy and majority of medication, which are demonstrated only on the surface of the skin.

Key words:
vacuum-compression therapy, metabolisms of extremities, trophic of extremities, peripheral capillary return, radiating diagnostics, and remission spectroscopy.

Numerical simulation of cardiovascular hemodynamics has become a popular tool for a surgeon's diagnosis of the cardiovascular diseases and a consequent medical treatment. A twelve segment numerical model of pulsating type has been developed at the IT CAS. This model includes the baroreflex negative feedback control and the description of the electrochemical and mechanical heart muscle activity, simulating the hemodynamic behavior of the cardiovascular system. The baroreflex control of the cardiovascular system is a regulatory feedback loop, which function is the maintenance of the blood perfusion pressure at the constant level and thus the maintenance of the oxygen delivery to body tissues. The baroreflex includes, beside other components, the arterial baroreceptors monitoring the blood pressure changes. Their activity is described in our model by the blood pressure and by the rate of pressure change. The baroreflex compensatory response to the circulatory failure caused by a sudden blood volume decrease, i.e. hemorrhagic shock, which results consequently in an insufficient oxygen delivery and other nutrients to satisfy metabolic demands of the body tissues, is demonstrated by our hemodynamic model.

Key words:
cardiovascular hemodynamics, numerical simulation, baroreflex control, hemorrhagic shock

Laparoscopic surgery is currently a well-established standard in many intra-abdominal procedures. Surgi-cal community has now accepted the advantages of this minimally invasive procedure. Laparoscopic sur-gery involves insufflation of intraabdominal cavity and raising abdominal wall, thus enabling surgeons to view intra-abdominal organs through a CCD fiberoptic camera with ease. However, the increase of intra-abdominal pressure by CO2 insufflation is impairing the diaphragmatic movement as well as compromis-ing venous return from the abdomen, pelvic and lower extremity.

We monitored hemodynamic profile of ten patients who underwent laparoscopic cholecystectomies. While conventional noninvasive monitoring, such as NIBP and saturation reading were within normal limits, HOTMANä System (HEMO SAPIENSâ INC, Sedona, AZ, USA) readings have shown that sev-eral hemodynamic parameters were in fact compromised to a significant degree during the insufflation of CO2 into abdominal cavity.

In conclusion, insufflation of CO2 impairs hemodynamic status of patients undergoing laparoscopic sur-gery. A closer and more cautious monitoring is therefore needed in order to prevent unwanted complica-tions.

Keywords:
laparoscopic surgery, hemodynamic profile

In general peritonitis due to typhoid ileal perforation, severe homeostasis disturbances occur as a result from typhoid fever, peritonitis, and shock syndrome. These insults are due to septicemia and endotoxamia as parts of pathophysiologic process of the disease.

To manage homeostasis disturbances occurring in this condition, hemodynamic monitoring of the patient is crucial. We used non-invasive hemodynamic monitoring hemodynamic parameters and oxygen trans-port with HOTMAN System (HEMO SAPIENS INC, Sedona, AZ, USA). Its noninvasive cardiac out-put measurement is as accurate as the standard method of invasive monitoring, as documented by Shoemaker (1994) and Wu (1995), resulting in r = 0.86, and P < 0.001 in their trials. In our hospital, patients with general peritonitis due to typhoid ileal perforation were monitored. Along with other clinical pa-rameters, hemodynamic readings were used as an adjunct of clinical decision in managing the patients. With the System's capability of measuring various hemodynamic parameters that demonstrate the per-formance of both cardiac contractility, preload and afterload conditions in a real time and in a continuous manner, the noninvasive monitoring renders the intensivist with trend of hemodynamic status of the pa-tient and it gives diagnostic guidelines and therapeutic goals to be achieved in certain period of time. However, the final clinical decision cannot be just relied on this tool, other clinical parameters should also be considered to avoid false decision based on the mere use of non-invasive monitoring.

In this study, we report our first ten cases of typhoid ileal perforation, which were monitored by multi component non-invasive monitoring, By this method, we observed continuously hemodynamic parameter and oxygen transport changes of these patients during resuscitation, induction of anaesthesia, intraoperative, and postoperative periods. Then, using regression analysis we analyzed the correlation between the hemodynamic and oxygen transport changes again the peripheral and systemic circulation performances, and renal function as an end organ during this period.

In conclusion, we found out that by using non-invasive monitoring, we could utilize the trend of hemody-namic status and oxygen transport of patients during perioperative period for guidelines of appropriate resuscitation and definitive treatment because of its capability in detecting early hemodynamic changes. In the perioperative period of general peritonitis due to typhoid ileal perforation inadequate hemodynamic status and oxygen transport correlated with poor systemic and peripheral circulation, and renal dysfunction. Further and well designed and controlled studies involving a large number of patients are obviously required to obtain more data in order to confirm the role of non-invasive monitoring in managing criti-cally ill patients with general peritonitis.

Keywords:
peritonitis, typhoid perforation, critically ill.

Conventional hemodynamics, taught today in medical schools as a part of cardiovascular physiology, is based upon the following assumptions and theses:

1. Hemodynamically significant parameters are the systolic and diastolic blood pressures and, in some patients, cardiac output (CO).
2. Measurement of CO is important only in high-risk or critically ill patients (~2% of the entire patient population).
3. Normal CO in resting adults is CO = 5.5 l/min.
4. A patient with constant oxygen demand (such as a resting, supine patient) also has a constant level of CO, heart rate (HR) and stroke volume (SV).
5. As a result of (2) and (3), it is clinically adequate to measure CO in these patients only infre-quently.
6. Measurement of central venous pressure (CVP) and pulmonary artery occluded pressure (PAOP) is crucial to determine blood volume levels. Knowledge of their values is essential in hemodynamic management decisions. They are as important as CO.
7. Measurement of CO is unimportant and/or unnecessary in other patients.
8. Measurement of arterial blood pressure alone is clinically adequate in management of hemo-dynamic disorders such as hypertension or heart failure.

The facts, however, are:

1. Adequate oxygen delivery is the primary determinant in a survival of high-risk, critically ill patient. [After all, since the primary function of cardiovascular system is oxygen delivery, we can stipulate that an adequate oxygen delivery under all metabolic conditions is a true defini-tion of cardiovascular health; it determines the quality of life and its duration.]
2. Hemodynamics deals with pressure-flow relationships. Both the blood pressure and blood flow has to be measured simultaneously.
3. Normal CO rate in all resting mammals is 0.1 l/min/kg.
4. Blood pressure in vessels is a result of blood flow and vessel resistance and wall compliance, blood pressure in chambers is a result of blood inflow and chamber compliance. Use of CVP or PAOP for determination of volume is flawed.
5. As a result of (1) and (2), hemodynamics has to be measured in every patient.
6. Even in a supine, resting patient the values of mean arterial blood pressure (MAP) and blood flow (SI) adjust to a new level for every heart beat.
7. Hemodynamically significant parameters, therefore, are MAP and SI.
8. CI is then a perfusion-significant parameter.
9. Hemodynamic state (SI @ MAP) is a result of beat-by-beat modulating effect of three hemo-dynamic modulators (volume, inotropy and vasoactivity). The perfusion flow (CI) is then set by a chronotropic modulation by HR.
10. Only normal levels of three hemodynamic and one perfusion modulator produce normohe-modynamic state (normotension @ normodynamic flow) and normoperfusion state (normo-chronotropy).

Key Words:
hemodynamics, Cardiac output, CVP, PAOP, MAP

Reference:
Sramek BB. Hemodynamics and its role in oxygen transport. Biomechanics of the Cardiovascular System. ISBN 80-900054-3-8. Czech Technical University & Foundation for Biomechanics of Man, 1995:209-231

A simultaneously measured Stroke Index (SI) and Mean Arterial Pressure (MAP) define the he-modynamic state. A new hemodynamic state is formed during every heartbeat through a beat-by-beat variation of three hemodynamic modulators - intravascular volume, inotropy and vasoactiv-ity. Subsequently, the chronotropic compensation by Heart Rate (HR) produces the perfusion-significant blood flow, Cardiac Index (CI). CI is the only dynamic modulator of Oxygen Delivery Index (DO2I). Adequacy of DO2I under all metabolic conditions is a true definition of cardiovas-cular health and a major determinant of survival in hospitalized patient, and quality of life and longevity in all persons.

Only a patient who is normovolemic, normoinotropic and normovasoactive can be in a normohe-modynamic state (normotension and normohemodynamic circulation). Normodynamic circulation in conjunction with normochronotropy results in a normoperfusion blood flow. This, together with normal level of hemoglobin and normal functioning of the lungs produces a normal oxygen delivery.

There are different normal hemodynamic, perfusion flow and oxygen delivery values as a func-tion of age (neonates, pediatrics, adults and geriatrics) and gender (gravidas and nongravidas).

The status of vasoactivity is defined by the value of the Stroke Systemic Vascular Resistance In-dex, SSVRI. The status of combined effects of [volume + inotropy] is defined by the Left Stroke Work Index, LSWI. The inotropic state can be determined either invasively via the intraventricu-lar (dP/dt) during isovolemic contraction phase or noninvasively by Thoracic Electrical Bioim-pedance as Inotropic State Index (ISI). The status of perfusion blood flow is defined by the level of CI.

A clinician who wants to therapeutically correct any observed hemodynamic abnormality of a patient (hypertension or hypotension, and/or low or hyperdynamic blood flow) has to (1) know the normal values of all hemodynamic and oxygen delivery dynamics parameters for this specific patient, (2) measure all these parameters and (3) identify which of the three hemodynamic modulators and one perfusion flow modulator [i.e., the causes] are at abnormal levels and (4) cor-rect them therapeutically. His therapeutic toolbox contains only 8 tools: Volume expanders or diuretics, positive or negative inotropes, vasoconstrictors or vasodilators/ACE inhibitors, and positive or negative chronotropes.

Key words:
Hemodynamics, oxygen transport dynamics, hemodynamic management

Reference:
Sramek BB. Hemodynamics and its role in oxygen transport. Biomechanics of the Cardiovascular System. ISBN 80-900054-3-8. Czech Technical University & Foundation for Biomechanics of Man, 1995:209-231

A number of techniques have been proposed for estimation of blood vessel elasticity. Some have been based upon measurements of variations in vessel diameter and blood pressure over the cardiac cycle, and the others on velocity measurements of propagation of the pressure/flow along the vessel. Recently, with progressive expansion of noninvasive imaging methods (e.g. magnetic resonance imaging (MRI), com-puted tomography (CT) and ultrasound), there is gaining ground in noninvasive evaluation of vascular system elasticity by using these methods.

The experimental in vitro measurements are needed for determination of mechanical properties of the arte-rial tissue. These experiments allow setting up conditions and scanning magnitudes, which is too inaccu-rate or impossible to be measured with in vivo methods and there can also be carried out a consequent histological analysis of the arterial tissue.

We have concentrated on developing an experimental device for movement scanning of aortic segment under pulsatile flow. The experimental device is developed to simulate quantifiable and repeatable pulsa-tile flow through excised cylindrical vessel segment under controlled hemodynamic conditions such as in-traluminal pressure, pulse pressure and frequency. The pressure pulse is generated by the piston, which is pneumatically driven by control unit.

The effects of individual flow parameters upon arterial wall mechanics are derived from simultaneous dy-namic measurements of these parameters and changes in the external vessel diameter. Two 1-line CCD cameras scan the vessel wall movement. The scanning frequency of these CCD cameras can reach up to 25kHz, which enables precise resolution in time. On the basis of vessel wall movement scanning we can determine pulse wave velocity in the vessel segment as well as the relationship between the external di-ameter and internal pressure (hysteresis loops).

This whole experimental device is made out of nonmagnetic materials. It enables us to carry out compara-tive measurements with MRI. On the basis of the comparative measurements with CT, MRI and CCD cameras, there can be verify validity and accuracy all of these methods for estimation of vessel wall elas-ticity. The relationship between the mechanical properties of the vessel wall and arterial diseases will be also investigated.


Key words: pulse wave velocity, arterial elasticity, pulsatile flow, hemodynamics