Related Experiment Video
Updated: Oct 29, 2025

Continuous Venous-Arterial Doppler Ultrasound During a Preload Challenge
Published on: January 20, 2023
Changes in pulse pressure variation to assess preload responsiveness in mechanically ventilated patients with
Olfa Hamzaoui1, Rui Shi2, Simone Carelli3
1Service de réanimation Polyvalente, Hôpital Antoine Béclère, AP-HP Université Paris-Saclay, Clamart, France.
Background:
Pulse pressure variation (PPV) is not reliable in predicting preload responsiveness in patients receiving mechanical with spontaneous breathing (SB) activity. We hypothesised that an increase in PPV after a tidal volume (VT) challenge (TVC) or a decrease in PPV during passive leg raising (PLR) can predict preload responsiveness in such cases.
Methods:
This prospective observational study was performed in two ICUs and included patients receiving mechanical ventilation with SB, for whom the treating physician decided to test preload responsiveness. Transthoracic echocardiography was used to measure the velocity-time integral (VTI) of the left ventricular outflow tract. Patients exhibiting an increase in VTI ≥12% during PLR were defined as PLR+ patients (or preload responders). Then, a TVC was performed by increasing VT by 2 ml kg-1 predicted body weight (PBW) for 1 min. PPV was recorded at each step.
Results:
Fifty-four patients (Simplified Acute Physiology Score II: 60 (25) ventilated with a VT of 6.5 (0.8) ml kg-1 PBW, were included. Twenty-two patients were PLR+. The absolute decrease in PPV during PLR and the absolute increase in PPV during TVC discriminated between PLR+ and PLR- patients with area under the receiver operating characteristic (AUROC) curve of 0.78 and 0.73, respectively, and cut-off values of -1% and +2%, respectively. Those AUROC curve values were similar but were significantly different from that of baseline PPV (0.61).
Conclusion:
In patients undergoing mechanical ventilation with SB activity, PPV does not predict preload responsiveness. However, the decrease in PPV during PLR and the increase in PPV during a TVC help discriminate preload responders from non-responders with moderate accuracy.
Clinical Trial Registration:
NCT04369027 (ClinicalTrials.gov).
Related Concept Videos
Measurement of Blood Pressure
Sites for measruring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement
Assessment of Ventilation I: Respiratory Rate
A Ventilation assessment is critical for monitoring a patient's health status. Respiration, one of the most accessible vital signs, provides insights into the function of numerous body systems and can indicate serious health issues, such as brainstem injuries from head trauma.
Critical Guidelines for Assessing Ventilation:
Ventilatory Modes
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...
Special considerations while measuring blood pressure
Monitoring Both Arms:
Monitoring BP in both arms during the initial assessment is advisable, as the systolic value may differ by five to ten mm Hg between arms. For subsequent BP assessments, use the arm with the higher reading.
Blood Pressure

