Change in cardiac output during Trendelenburg maneuver is a reliable predictor of fluid responsiveness in patients with acute respiratory distress syndrome in the prone position under protective ventilation

Yonis et al. Critical Care Change in cardiac output during Trendelenburg maneuver is a reliable predictor of fluid responsiveness in patients with acute respiratory distress syndrome in the prone position under protective ventilation Hodane Yonis 1 4 Laurent Bitker 1 4 Mylène Aublanc 0 1 3 4 Sophie Perinel Ragey 0 1 3 4 Zakaria Riad 0 1 3 4 Floriane Lissonde 1 4 Aurore Louf-Durier 1 4 Sophie Debord 0 1 3 4 Florent Gobert 0 1 3 4 Romain Tapponnier 1 4 Claude Guérin 0 1 2 3 4 Jean-Christophe Richard 0 1 3 4 5 0 Université de Lyon, Université LYON I , Lyon , France 1 Service de Réanimation Médicale, Hôpital De La Croix Rousse, Hospices Civils de Lyon , 103 Grande Rue de la Croix Rousse, 69004 Lyon , France 2 IMRB, INSERM 955Eq13 , Créteil , France 3 Université de Lyon, Université LYON I , Lyon , France 4 Service de Réanimation Médicale, Hôpital De La Croix Rousse, Hospices Civils de Lyon , 103 Grande Rue de la Croix Rousse, 69004 Lyon , France 5 CREATIS INSERM 1044 CNRS 5220 , Villeurbanne , France Background: Predicting fluid responsiveness may help to avoid unnecessary fluid administration during acute respiratory distress syndrome (ARDS). The aim of this study was to evaluate the diagnostic performance of the following methods to predict fluid responsiveness in ARDS patients under protective ventilation in the prone position: cardiac index variation during a Trendelenburg maneuver, cardiac index variation during an end-expiratory occlusion test, and both pulse pressure variation and change in pulse pressure variation from baseline during a tidal volume challenge by increasing tidal volume (VT) to 8 ml.kg-1. Methods: This study is a prospective single-center study, performed in a medical intensive care unit, on ARDS patients with acute circulatory failure in the prone position. Patients were studied at baseline, during a 1-min shift to the Trendelenburg position, during a 15-s end-expiratory occlusion, during a 1-min increase in VT to 8 ml.kg-1, and after fluid administration. Fluid responsiveness was deemed present if cardiac index assessed by transpulmonary thermodilution increased by at least 15% after fluid administration. Results: There were 33 patients included, among whom 14 (42%) exhibited cardiac arrhythmia at baseline and 15 (45%) were deemed fluid-responsive. The area under the receiver operating characteristic (ROC) curve of the pulse contourderived cardiac index change during the Trendelenburg maneuver and the end-expiratory occlusion test were 0.90 (95% CI, 0.80-1.00) and 0.65 (95% CI, 0.46-0.84), respectively. An increase in cardiac index ≥ 8% during the Trendelenburg maneuver enabled diagnosis of fluid responsiveness with sensitivity of 87% (95% CI, 67-100), and specificity of 89% (95% CI, 72-100). The area under the ROC curve of pulse pressure variation and change in pulse pressure variation during the tidal volume challenge were 0.52 (95% CI, 0.24-0.80) and 0.59 (95% CI, 0.31-0.88), respectively. (Continued on next page) - (Continued from previous page) Conclusions: Change in cardiac index during a Trendelenburg maneuver is a reliable test to predict fluid responsiveness in ARDS patients in the prone position, while neither change in cardiac index during end-expiratory occlusion, nor pulse pressure variation during a VT challenge reached acceptable predictive performance to predict fluid responsiveness in this setting. Trial registration: ClinicalTrials.gov, NCT01965574. Registered on 16 October 2013. The trial was registered 6 days after inclusion of the first patient. Background Predicting fluid responsiveness is of paramount importance to avoid unnecessary fluid administration in patients with acute respiratory distress syndrome (ARDS), since a positive fluid balance is strongly associated with ARDS mortality [1, 2]. Several tests with high reliability in prediction of fluid responsiveness may help optimization of fluid administration to achieve a neutral or negative fluid balance in this condition. Pulse pressure variation (PPV) [3–5] and other related tests exploring intra-tidal cyclic changes in hemodynamics during mechanical ventilation [6–9] are highly reliable to detect fluid responsiveness, as long as the tidal volume (VT) is greater than 8 ml.kg-1, the cardiac rhythm is regular, the ratio of heart rate to respiratory rate remains high [10], and both compliance of the respiratory system and abdominal pressure stay in the normal range. However, all these validity criteria are strongly challenged in patients with ARDS under protective ventilation [11–13], even more so in the prone position (PP). Cardiac index variation during an end-expiratory occlusion (EEO), by transiently suppressing cardiopulmonary interaction, and hence the cyclic impediment to cardiac preload during inspiration, is reliable in supine patients with ARDS to detect fluid responsiveness [14], but has been validated with VT slightly higher than 6 ml.kg-1. Since low respiratory system compliance (...truncated)