Prediction of volume-responsiveness during one-lung ventilation: a comparison of static, volumetric, and dynamic parameters of cardiac preload

OBJECTIVES: The aim of this study was to evaluate the ability of static, volumetric, and dynamic parameters of cardiac preload to predict volume responsiveness during one-lung ventilation (OLV).

DESIGN: Prospective experimental study.

SETTING: Laboratory of the animal facility of the University Medical Center Hamburg-Eppendorf.

PARTICIPANTS: Twenty-three German domestic pigs.

INTERVENTIONS: Hypovolemia was induced by withdrawing 20 mL/kg body weight (BW) of blood. OLV was established, and the volume withdrawn was re-transfused in 3 volume-loading steps, each consisting of 7 mL/kg BW. An ultrasonic flow probe around the pulmonary artery was used to measure the stroke-volume index (SVI) and to evaluate the volume response. An increase in the SVI of ≥ 15% was considered a positive response. For each measurement time point, central venous pressure (CVP), left atrial pressure (LAP), the global end-diastolic volume index (GEDI), stroke-volume variation (SVV), and pulse-pressure variation (PPV) were recorded. The ability to predict volume responsiveness was assessed using ROC analysis.

MEASUREMENTS AND MAIN RESULTS: A total of 69 volume loading steps were performed, 48 of which showed a positive volume response. ROC analysis revealed the following area under the curve (AUC) values: CVP, 0.88; LAP, 0.65; GEDI, 0.75; SVV, 0.78; and PPV, 0.83. A comparison of the areas under the ROC curves did not reveal any statistically significant differences (p>0.05), with the exception of LAP compared with CVP (p = 0.005).

CONCLUSIONS: Under these OLV experimental conditions, the volumetric and dynamic parameters of preload, as well as CVP, seemed to be of similar value in predicting volume responsiveness.