Intensive Care Med (2007) 33:1133–1138 DOI 10.1007/s00134-007-0642-y ORIGINAL Julien Maizel Norair Airapetian Emmanuel Lorne Christophe Tribouilloy Ziad Massy Michel Slama Diagnosis of central hypovolemia by using passive leg raising Received: 11 October 2006 Accepted: 27 March 2007 Published online: 17 May 2007 © Springer-Verlag 2007 This article is discussed in the editorial available at: http://dx.doi.org/10.1007/ s00134-007-0645-8. J. Maizel · N. Airapetian · M. Slama (✉) CHU Sud, Unite de Reanimation Medicale, Service de Nephrologie, 80054 cedex 1 Amiens, France e-mail: slama.michel@chu-amiens.fr Tel.: +33-3-22455854 Fax: +33-3-22455664 J. Maizel · E. Lorne · C. Tribouilloy · Z. Massy · M. Slama ERI 12, INSERM, Amiens, France Abstract Objective: Suspected cen- tral hypovolemia is a frequent clinical situation in hospitalized patients, and no simple bedside diagnostic test in spontaneously breathing patients is available. We tested the value of passive leg raising to predict hemo- dynamic improvement after fluid expansion in patients with suspected central hypovolemia. Design and setting: Prospective study in four intensive care units at the Amiens university hospital. Thirty-four spon- taneously breathing patients with suspected hypovolemia were included and were classified as responders (cardiac output increased by 12% or more after fluid expansion) or nonresponders. Patients were ana- lyzed in the supine position during 30° leg raising and after fluid expan- sion. Measurements and results: Stroke volume and cardiac output determined by echocardiographic and Doppler techniques and heart rate and blood pressure were measured at baseline, during passive leg raising and after fluid expansion. An in- crease of cardiac output or stroke volume by 12% or more during passive leg raising was highly pre- dictive of central hypovolemia (AUC 0.89 ± 0.06, 95% CI 0.73–0.97 for cardiac output and AUC 0.9 ± 0.06, 95% CI 0.74–0.97 for stroke volume). Sensitivity and specificity values were 63% and 89% for cardiac output and 69%, 89% for stroke volume respec- tively. A close correlation (r = 0.75; p < 0.0001) was observed between cardiac output changes during leg raising and changes in cardiac output after fluid expansion. Conclusions: Bedside measurement of cardiac output or stroke volume by Doppler techniques during passive leg raising was predictive of a positive hemo- dynamic effect of fluid expansion in spontaneously breathing patients with suspected central hypovolemia. Introduction In many clinical situations, such as hypotension, shock, functional renal failure, oligoanuria, or clinical and/or laboratory signs of dehydration, central hypovolemia may be suspected, raising the question of whether fluid expan- sion is required to increase central blood volume [1, 2]. In these clinical situations, volume infusion induces significant increase in cardiac output because the heart (left and right ventricles) works on the stiff portion of the Frank–Starling relationship, and therefore increases organ perfusion and blood flow. The development of a predictive index of preload dependency, and thus of fluid responsiveness, in patients with suspected central hypo- volemia therefore constitutes a major clinical challenge. Such indices were recently introduced and validated in intubated and mechanically ventilated patients [3–6]. In spontaneously breathing patients, these indices appear inaccurate because they strongly depend on respiratory status, which is not controlled in this case. Although the