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 OLV was established, and the volume withdrawn was re-transfused in 3 volume-loading steps, each consisting of 7 mL/kg BW.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.