Should we use diastolic function parameters to determine preload responsiveness in cardiac surgery? A pilot study

Area of Science:

• Cardiology
• Anesthesiology
• Critical Care Medicine

Background:

• Left ventricular diastolic function (LV DF) is a potential predictor of fluid responsiveness.
• Few studies have investigated the role of diastolic function in fluid responsiveness.
• This pilot study aimed to assess LV and right ventricular diastolic function parameters in predicting fluid responsiveness.

Purpose of the Study:

• To determine if diastolic function parameters, including the mitral E/e' ratio, predict fluid responsiveness in patients undergoing coronary artery bypass grafting (CABG).
• To compare echocardiographic and hemodynamic parameters, including pulse pressure variation and stroke volume variation (SVV), for fluid responsiveness assessment.

Main Methods:

• Prospective study of 57 patients undergoing CABG.
• Fluid responsiveness assessed by a 15% increase in cardiac index after 500 mL crystalloid infusion.
• Measurements included transesophageal echocardiography (TEE), radial arterial catheter, and pulmonary artery catheter (for cardiac output).

Main Results:

• 21 responders (36.8%) and 36 non-responders (63.2%) were identified.
• No significant differences in baseline diastolic function parameters (mitral, tricuspid, pulmonary, or hepatic venous flows, or E/e' ratio) between responders and non-responders.
• Stroke volume variation (SVV) was the only independent predictor of fluid responsiveness (P = 0.0208).

Conclusions:

• Diastolic function parameters were not associated with fluid responsiveness in CABG patients.
• Stroke volume variation (SVV) emerged as the most reliable parameter for predicting fluid responsiveness in this cohort.