Fig 1.
Serial passive leg raising (PLR) maneuver protocol.
Patients were placed in the semi-recumbent position at 45° for 3 minutes and baseline hemodynamic values were recorded. PLR was induced by raising both lower extremities to 30–45° using a standard wedge pillow and held in this position for 3 minutes. After data collection, the patient was returned to the semi-recumbent resting position for 20–30 minutes. The PLR maneuver was repeated for 2 additional cycles.
Table 1.
Patient and volunteer baseline characteristics.
BMI–body mass index; SOFA–sequential organ failure assessment. Data are presented as mean ± standard deviation or as count (percentage).
Fig 2.
Correlation and agreement between cycles of passive leg raising (PLR) maneuvers.
A. Patients. B. Volunteers. r–Pearson’s correlation coefficients. K–Cohen’s kappa for agreement in determining fluid responsiveness of “Yes” (ΔSVI > 10%) or “No” (ΔSVI ≤ 10%) between two PLR maneuvers. K was not calculated for volunteers since the consistency in determining fluid responsiveness over all three PLR maneuvers was 96.0% (Table 3).
Table 2.
Change in hemodynamic measurement with three cycles of passive leg raise (PLR) maneuvers.
SVI–stroke volume index; CI–cardiac index; ΔSVI–change in stroke volume index after the PLR maneuver; ΔCI–change in cardiac index after the PLR maneuver. Data are represented as mean ± standard deviation.
Table 3.
Precision and consistency of passive leg raise in determining fluid responsiveness.
Precision is described by the range, average deviation, and standard deviation of the change in stroke volume index (ΔSVI) over 3 cycles of passive leg raising (PLR) maneuver. Consistency was defined as the same fluid responsiveness determination of “Yes” (ΔSVI > 10%) or “No” (ΔSVI ≤ 10%) over the 3 cycles of PLR maneuver. For example, a subject was categorized to have consistent results if they were persistently fluid responsive or not fluid responsive for all 3 cycles of PLR maneuver. A subject had inconsistent results if any one of the 3 cycles of PLR maneuver resulted in a fluid responsiveness determination that was different from the other PLR’s. Data are represented as mean ± standard deviation or as count (percentage).