Critical Care · Sepsis · Clinical Pearl
Passive leg raise is a fluid challenge you can take back
Lede: Passive leg raising transiently transfers venous blood to the central circulation and tests preload responsiveness without committing a fluid bolus.
Why it matters
The maneuver remains interpretable across arrhythmia and ventilation modes when its effect is measured with a direct cardiac-output or stroke-volume signal. The review emphasizes measuring within 30–90 seconds and using a roughly 10% rise in stroke volume or VTI as the conventional response threshold.
The pearl
Measure flow, not blood pressure. A PLR is only useful when paired with a direct stroke-volume or cardiac-output measurement.
