Can dynamic indicators help the prediction of fluid responsiveness in spontaneously breathing critically ill patients?

Byline: Stephane Soubrier (1,2), Fabienne Saulnier (1,2), Herve Hubert (2), Pierre Delour (1), Helene Lenci (1), Thierry Onimus (1,2), Saad Nseir (1,2), Alain Durocher (1,2) Keywords: Fluid responsiveness; Volume expansion; Arterial pulse pressure; Arterial systolic pressure; Preload; Heart--lung interactions Abstract: Objective To investigate whether the respiratory changes in arterial pulse (IPP) and in systolic pressure (ISP) could predict fluid responsiveness in spontaneously breathing (SB) patients. Because changes in intrathoracic pressure during spontaneous breathing (SB) might be insufficient to modify loading conditions of the ventricles, performances of indicators were also assessed during a forced respiratory maneuver. Design Prospective interventional study. Setting A 34-bed university hospital medico-surgical ICU. Patients and participants Thirty-two SB patients with clinical signs of hemodynamic instability. Intervention A 500-ml volume expansion (VE). Measurements and results Cardiac index, assessed using transthoracic echocardiography, increased by at least 15% after VE in 19 patients (responders). At baseline, only dynamic indicators were higher in responders than in nonresponders (13a-+-a-5% vs. 7a-+-a-3%, pa-=a-0.003 for IPP and 10a-+-a-4% vs. 6a-+-a-2%, pa-=a-0.002 for ISP). Moreover, they significantly decreased after VE (11a-+-a-5% to 6a-+-a-4%, pa- Conclusions Due to their lack of sensitivity and their dependence to respiratory status, IPP and ISP are clearly less reliable to predict fluid responsiveness during SB than in mechanically ventilated patients. However, when their baseline value is high without acute right ventricular dysfunction in a participating patient, a positive response to fluid is likely. Author Affiliation: (1) Service de Reanimation Medicale, Hopital Calmette, CHRU, boulevard du Pr Leclercq, 59037, Lille cedex, France (2) EA 3614, Lille II University, 59000, Lille, France Article History: Registration Date: 28/03/2007 Received Date: 13/05/2005 Accepted Date: 27/03/2007 Online Date: 17/05/2007 Article note: This study was presented at the American Thoracic Society international conference, 2005, San Diego, California. This article is discussed in the editorial available at: http://dx.doi.org/10.1007/s00134-007-0645-8.