Friendly help for clinical use of maternal hemodynamics

Maternal hemodynamics plays a major role during pregnancy and its evaluation is fundamental to understand obstetric conditions. The modern opinion about maternal hemodynamics assessment is to shift focus from single hemodynamic parameters to the whole hemodynamic profile. Our aim is to create a simple, intuitive, and easily understandable graphing technique to evaluate the main hemodynamic parameters.

We enrolled 531 pregnant women without maternal or fetal disease. One hundred and forty five in the first trimester of pregnancy, 258 in the second one and 128 in the third one. We performed hemodynamic assessment with ultrasonic cardiac output monitor method. We selected the six main parameters: cardiac output, systemic vascular resistance, heart rate, potential-to-kinetic energy ratio, inotropy index, and stroke volume variation. We chose the radar chart to display the multivariate data of the hemodynamic measurement of the patient in evaluation.

We have obtained mean and deviation standard values for the six main hemodynamic parameters in every trimester. They deeply change during the pregnancy, so it is correct to compare a new hemodynamic measurement with the mean values for the specific trimester in order to evaluate any possible alterations. In fact, once a new hemodynamic assessment is performed, we calculate the Z-score in order to fix the positions of the six measured parameters in their specific axis of radar chart.

At the end of a hemodynamic exam, the physician can input the data in the program obtaining a graphic representation. Using this technique, which simultaneously evaluates six hemodynamic parameters, it is possible to easily understand the patient's hemodynamic status. By converting the parameters values in Z-score, it is easier to understand when hemodynamics is altered, even if the physician does not have any experience in maternal hemodynamics.