The ��PLRSV cutoff is close to ultrasonic interindividual reproducibility. This threshold is comparable to values usually recorded in the ICU [17,29] and is more than twice the values of inter- inhibitor Pacritinib and intraindividual reproducibility. We assessed SV using TTE, which has been validated against the thermodilution technique [30]. Thermodilution monitoring cannot be used because of recirculation phenomena [31], and preload reserve haemodynamic indices are not currently validated in this setting for the reasons described above. There were some concerns about the safety of PLR among ECMO patients. In our cohort, all patients underwent PLR without any adverse impact on the ECMO system. Before PLR, however, precautions were taken regarding the length of inflow and outflow cannulas.
ConclusionsIn this study, a > 10% increase in ��PLRSV was predictive of fluid responsiveness in patients placed on venovenous ECMO respiratory assistance. This diagnostic procedure is easy to perform, reversible, familiar to intensive care physicians and easily reproducible, and it may be helpful in reliably identifying patients who will benefit from fluid loading. In contrast, we have not demonstrated that ��PLRPO and ��respPP can be used to predict volume responsiveness. Further studies of a larger sample of patients placed on various types of ECMO are necessary to assess these results.Key messages? Derivative pulse pressure indices (��respPP and ��PLRPP) failed to predict fluid responsiveness in ARDS patients placed on venovenous ECMO.? A > 10% increase of ��PLRSV may predict fluid responsiveness in patients treated with venovenous ECMO.
? ��PLRPO cannot be used to predict fluid responsiveness.Abbreviations��PLRPO: passive leg raising pump outflow change; ��PLRPP: passive leg raising pulse pressure change; ��PLRSV: passive leg raising stroke volume change; ��respPP: respiratory pulse pressure variation; ��respSV: respiratory stroke volume variation; ARDS: acute respiratory distress syndrome; CI95: 95% confidence interval; CO: cardiac output; CVC: central venous catheter; CVP: central venous pressure; DAP: diastolic arterial pressure; ECMO: extracorporeal membrane oxygenation; IRB: Institutional Review Board; LVEF: left ventricular ejection fraction; MAP: median arterial pressure; PI: pulse index; PO: pump outflow; PLR: passive leg raising; ROC: receiver operating characteristic; RPM: rotation per minute; SAP: systolic arterial pressure; SD: standard deviation; SV: stroke volume; TTE: transthoracic echocardiography; VE: volume expansion; VTIAo: aortic velocity-time integral ratio.
Competing interestsThe authors declare that they have no competing interests.Authors’ contributionsPGG conceived, designed and coordinated the study and drafted the manuscript. EZ, MD and TC participated in the coordination of the Cilengitide study.