Brachial cuff measurements of blood pressure during passive leg raising for fluid responsiveness prediction

Abstract

ObjectiveThe passive leg raising maneuver (PLR) for fluid responsiveness testing relies on cardiac output (CO) measurements or invasive measurements of arterial pressure (AP) whereas the initial hemodynamic management during shock is often based solely on brachial cuff measurements. We assessed PLR-induced changes in noninvasive oscillometric readings to predict fluid responsiveness. Study designMulticentre interventional study. Patients and methodsIn ICU sedated patients with circulatory failure, AP (invasive and noninvasive readings) and CO measurements were performed before, during PLR (trunk supine, not modified) and after 500-mL volume expansion. Areas under the ROC curves (AUC) were determined for fluid responsiveness (>10% volume expansion-induced increase in CO) prediction. ResultsIn 112 patients (19% with arrhythmia), changes in noninvasive systolic AP during PLR (noninvasiveΔPLRSAP) only predicted fluid responsiveness (cutoff 17%, n=21, positive likelihood ratio [LR] of 26 [18–38]), not unresponsiveness. If PLR-induced change in central venous pressure (CVP) was at least of 2mmHg (n=60), suggesting that PLR succeeded in altering cardiac preload, noninvasiveΔPLRSAP performance was good: AUC of 0.94 [0.85–0.98], positive and negative LRs of 5.7 [4.6–6.8] and 0.07 [0.009–0.5], respectively, for a cutoff of 9%. Of note, invasive AP-derived indices did not outperform noninvasiveΔPLRSAP. ConclusionRegardless of CVP (i.e., during “blind PLR”), noninvasiveΔPLRSAP more than 17% reliably identified fluid responders. During “CVP-guided PLR”, in case of sufficient change in CVP, noninvasiveΔPLRSAP performed better (cutoff of 9%). These findings, in sedated patients who had already undergone volume expansion and/or catecholamines, have to be verified during the early phase of circulatory failure (before an arterial line and/or a CO measuring device is placed).