On completion of this article, the reader should be able to:
- Define static and dynamic indexes.
- List indexes that are valuable to predict fluid responsiveness in spontaneously breathing patients.
- Use this information in a clinical setting.
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Wolters Kluwer Health has identified and resolved all faculty conflicts of interest regarding this educational activity.
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In spontaneously breathing patients, indexes predicting hemodynamic response to volume expansion are very much needed. The present review discusses the clinical utility and accuracy of indexes tested as bedside indicators of preload reserve and fluid responsiveness in hypotensive, spontaneously breathing patients.
We conducted a literature search of the MEDLINE database and the trial register of the Cochrane Group.
Identification of reports investigating, prospectively, indexes of fluid responsiveness in spontaneously breathing critically ill patients. All the studies defined the response to fluid therapy after measuring cardiac output and stroke volume using the thermodilution technique. We did not score the methodological quality of the included studies before the data analysis.
A total of eight prospective clinical studies in critically ill patients were included. Only one publication evaluated cardiac output changes induced by fluid replacement in a selected population of spontaneously breathing critically ill patients.
Based on this review, we can only conclude that static indexes are valuable tools to confirm that the fluid volume infused reaches the cardiac chambers, and therefore these indexes inform about changes in cardiac preload. However, respiratory variation in right atrial pressure, which represents a dynamic measurement, seems to identify hypotension related to a decrease in preload and to distinguish between responders and nonresponders to a fluid challenge.
Further studies should address the question of the role of static indexes in predicting cardiac output improvement following fluid infusion in spontaneously breathing patients.
Research Fellow, Surgical Intensive Care (AC), Lecturer (J-AR), Scientific Assistant Professor, Chef de Clinique Scientifique (KB), Geneva University Hospital, Geneva, Switzerland; Associate Professor of Anesthesiology, University of Washington, Seattle, WA (MT).
The authors declare no conflict of interest.
Address requests for reprints to: Karim Bendjelid, MD, MS, Surgical Intensive Care Division, Geneva University Hospitals, CH-1211 Geneva 14, Switzerland. E-mail: Karim.Bendjelid@hcuge.ch