Central venous pressure measurements improve the accuracy of leg raising-induced change in pulse pressure to predict fluid responsiveness

Abstract

Purpose: Passive leg raising (PLR) is a maneuver performed to test the cardiac Frank-Starling mechanism. We assessed the influence of PLR-induced changes in preload on the performance of PLRinduced change in pulse pressure (δPLRPP) and cardiac output (δPLRCO) for fluid responsiveness prediction. Methods: Sedated, nonarrhythmic patients with persistent shock were included in this prospective multicenter study. Cardiac output and pulse pressure were measured at baseline (patient supine), during PLR (lower limbs lifted to 45°) and after 500-ml volume expansion. Patients were classified as responders or not. Results: In the whole population (n = 102), the area under the receiver-operating characteristic curve (AUC) was 0.76 for δPLRPP and was higher for DPLRCO (0.89)(p<0.05), but likelihood ratios were close to 1. In patients with a PLR-induced increase in central venous pressure (CVP) of at least 2 mmHg (n = 49), δ PLRPP and δPLRCO disclosed higher AUCs than in the rest of the population (0.91 vs. 0.66 and 0.98 vs. 0.83; p<0.05); positive/negative likelihood ratios were 9.3/0.14 (8% cutoff level) and 30/0.07 (7% cutoff level), respectively. Conclusions: A PLRinduced change in CVP ≥2 mmHg was required to allow clinical usefulness of PLR-derived indices. In this situation, δPLRPP performed well for predicting fluid responsiveness in deeply sedated patients. © 2010 jointly held by Springer and ESICM.