Indikation und Steuerung der Volumentherapie

[Functional hemodynamic monitoring]

BACKGROUND

Critically ill patients in the intensive care unit require intensified monitoring to control the treatment with volume and/or vasoactive substances.

RESEARCH QUESTION

What role does functional hemodynamic monitoring play in controlling treatment and what techniques are used to manage this?

MATERIAL AND METHODS

Review of the current literature.

RESULTS AND DISCUSSION

Precise knowledge of the physiology of the cardiovascular system as well as the pathophysiology of individual clinical pictures and the possibilities of invasive and noninvasive monitoring are the prerequisites for the indications, implementation and interpretation of functional hemodynamic monitoring. An understanding of the heart-lung interaction and the influence of invasive ventilation on the volumetric target parameters, such as stroke volume variation, systolic pressure variation and pulse pressure variation as well as sonography of the inferior vena cava are indispensable prerequisites for the question of volume responsiveness. Other maneuvers, such as the passive leg raising test, can be very helpful when deciding on volume administration in everyday clinical practice. Static parameters such as central venous pressure generally play no role and if any only a subordinate one.

[Monitoring of Fluid Therapy]

Fluid and volume therapy is of paramount importance in anaesthesia and intensive care medicine. Fluid replacement as well as volume therapy can cause hypervolemia with deleterious consequences. Therefore, a prerequisite for an adequate volume therapy is the assessment of fluid responsiveness. Several monitoring techniques for evaluation of volume status and of volume responsiveness are currently used. However, there are several limitations of the different monitoring techniques that the user should be aware of. An algorithm can be helpful for a structured approach in monitoring volume therapy.

[Hemorrhagic shock : General principles]

Bleeding associated with hemorrhagic shock is often seen in emergency medical services or in the intensive care unit. Identifying the origin of the bleeding and additional disorders helps to determine the degree of the hemorrhagic shock. In order to be effective, the initial therapy until blood products are available needs to be differentiated to be effective in terms of hemodynamic stabilization and coagulation. Crystalloidal and colloidal solutions should be used carefully since those solutions bear a risk within themselves. Treatment of acidosis and hypothermia can further reduce bleeding complications. Early and repeated monitoring of clotting should be performed simultaneously to shock therapy to permit specific treatment and substitution of coagulation factors if needed. Hemorrhagic shock therapy should be continued until bleeding is stopped.

[Hemodynamic monitoring of critically ill patients : Bedside integration of data]

BACKGROUND

Hemodynamic monitoring of critically ill patients is a key issue in intensive care medicine. Indication and application of invasive hemodynamic monitoring is a highly complex matter and requires thorough professional education and training.

MATERIALS AND METHODS

A literature review was performed.

RESULTS

A pragmatic approach can be divided into several steps such as medical history, physical examination, imaging, and laboratory results, which support the primary working diagnosis and allow further clarification of the underlying pathophysiology. Invasive arterial blood pressure and cardiac output measurement as well as components of the functional hemodynamic monitoring help to assess fluid responsiveness and to guide volume loading, diuretic therapy as well as administration of vasoactive or positive inotrope substances.

CONCLUSIONS

All information gathered through medical history, physical examination, imaging, and hemodynamic monitoring help to form an overall picture and should be reevaluated regularly and in individual cases very closely depending on the hemodynamic instability of the patient. Target values are strictly indicative and are not binding taking into account that each patient has its unique pathophysiological profile.