The reliability and validity of passive leg raise and fluid bolus to assess fluid responsiveness in spontaneously breathing emergency department patients

Purpose: We investigated the reproducibility of passive leg raise (PLR) and fluid bolus (BOLUS) using the Non-Invasive Cardiac Output Monitor (NICOM; Cheetah Medical, Tel Aviv, Israel) for assessment of fluid responsiveness (FR) in spontaneously breathing emergency department (ED) patients. Methods: Prospective, observational study of a convenience sample of adult ED patients receiving intravenous fluid bolus. We assessed stroke volume (SV) using NICOM and obtained results from PLR, where the head of the bed was changed from semirecumbent to supine while the patients' legs raised to 45° for 3 minutes. Fluid bolus was defined as 5 mL/kg normal saline infusion. Maximal increase in SV was recorded. Fluid responsiveness was defined as an increase of SV greater than 10% from baseline. We obtained 4 consecutive responses for each patient; PLR1, PLR2, BOLUS1 separated each by 10 minutes, and BOLUS2 initiated immediately after the end of BOLUS1. We calculated κ statistics, correlation coefficients, and odds ratios with 95% confidence interval and Bland-Altman plots. Results: We enrolled 109 patients enrolled in this study. The 2 PLRs were significantly correlated (r = 0.78, P < .001) with κ = 0.46 for FR (P < .001). The 2 BOLUSES less strongly correlated (r = 0.14, P = .001) and κ = 0.06 for FR (P < .001). Patients who were responsive to PLR1 had 9.5 (3.6-25) odds of being FR for PLR2, whereas those responsive to BOLUS1 had a 1.8 (0.76-4.3) increased odds of FR for BOLUS2. Conclusion: In conclusion, we have found PLR as measured by the NICOM to be a promising tool for the evaluation of SV responsiveness. It was feasible for use in the ED, and the data suggest that the PLR technique may be more reproducible than the fluid bolus technique for assessing volume responsiveness.