الفهرس 
Physiological background
Hemodynamic ValuesOnly 14 pages are availabe for public view
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Abstract
Hemodynamics is the study of the motion of blood through the body. It plays an important role in the management of acutely ill patient. Assessment and monitoring of hemodynamics is a cornerstone in critically ill patients as hemodynamic alteration may become life-threatening in a few minutes. Clinical examination alone may not be accurate in the ICU environment. The pathophysiology of critical illness differs from that of the relatively stable ward patient; consequently, clinical findings may not be as helpful. For that reason technological advances and new tools are being introduced in the ICU that assists healthcare providers in the evaluation of the volume and hemodynamic status of their patients.
Monitoring may be important in two parallel ways; it can help to identify underlying pathophysiological processes so that appropriate forms of therapy can be selected. Or it may be more preventive, as monitoring allowing preemptive actions to be performed before a significant problem arises. Defining normal values in critically ill patients is not easy; because ’normality’ is usually referred to healthy subjects at rest. The concept of normal hemodynamics is not easy to define in critically ill patients. In general, hemodynamics is adequate when the oxygen delivery to the tissues is sufficient to maintain an aerobic metabolism. This may occur in critically ill patients at hemodynamic values greater than or lower than the values considered normal in healthy subjects at rest. The hemodynamics may be still adequate if it guarantees an aerobic metabolism.
Hemodynamic monitoring can only improve outcomes if three conditions are met: 1- the data obtained from the monitoring device were sufficiently accurate to be able to influence therapeutic decision making; 2- the data obtained from the monitoring system were relevant to the patient being monitored; 3- and changes in management made as a result of the data obtained need to be able to improve outcomes. Monitoring requirements may vary over time and can depend on local equipment availability and training. Effective hemodynamic monitoring needs to combine and integrate variables, continuous measurement of all variables as changes occur over short periods.
Hemodynamics monitoring can be very easy to be just measuring the pulse and blood pressure or may be more recent complicated approaches. Monitoring approaches are classified into basic non invasive cardiac monitoring and advanced monitoring. Basic non-invasive cardiac monitoring as; blood pressure, respiratory rate, oxygen saturation and heart rate. Advanced monitoring that may be invasive as pulmonary artery catheter; less invasive as systemic artery catheter, continuous pulse contour cardiac analysis and central venous oxygen saturation; or non invasive as ECHO and esophageal Doppler. Tissue perfusion as Bowman perfusion monitor. Each of these methods has its advantages and limitation, with proper decision when to use and when not. For that it needs a trained staff to decide when to use and for better interpretation of the results.