Invasive and Non-invasive Dynamic Parameters to Predict Fluid Responsiveness After Off-pump Coronary Surgery

This study aimed to assess the predictive value of invasive and non-invasive dynamic parameters for evaluation of fluid responsiveness after off-pump coronary artery bypass grafting.

Thirty-two adult patients after off-pump coronary surgery were enrolled into a single-center pilot prospective observational study. After arrival to the intensive care unit, all patients received standard fluid challenge test to assess fluid responsiveness. The patients with an increase in cardiac index ≥ 15% after the test were defined as fluid responders. We measured pulse pressure variation using 2 monitoring systems (PPVPiCCO and PPVNK), stroke volume variation, heart-lung interaction index, and plethysmogram variability index before and after standard fluid challenge test.

After intensive care unit admission, the absolute values of stroke volume variation, PPVPiCCO, PPVNK, and heart-lung interaction index were significantly higher among fluid responders (P < .05). Response to standard fluid challenge test was predicted by dynamic assessment of PPVPiCCO (area under the curve 0.84), PPVNK (area under the curve 0.71), stroke volume variation (area under the curve 0.77), and heart-lung interaction index (area under the curve 0.77) (P < .05). The plethysmogram variability index value did not demonstrate any predictive ability regarding fluid responsiveness (area under the curve 0.5, P =.1).

In patients after off-pump coronary surgery, both invasive parameters such as pulse pressure and stroke volume variations and non-invasive parameter such as heart-lung interaction index are able to predict fluid responsiveness. Thus, these dynamic parameters can be used to guide fluid therapy during the early postoperative period after off-pump coronary surgery.