A Comparison of Echocardiography and the Pressure Recording Analytical Method (PRAM) for Predicting Fluid Responsiveness after Passive Leg Raising

Abstract

Objective: This study aims to assess the agreement between the cardiac index (CI) measured by pressure recording analytical method (PRAM) and transthoracic echocardiography (TTE) before and after the passive leg raise (PLR) maneuver.

Methods: This is a prospective observational study in critically ill patients who were monitored with MostcareUp/PRAM (Vygon, Vytech, Padova, Italy). Cardiac index (CI) values and percent changes in CI values in response to PLR were recorded by TTE and PRAM.

Results: Data of a total of 25 patients were collected. The median CI values that were calculated by TTE before and after PLR were 2.5 (1.2-4.7) L/min/m(2) and 2.9 (1.4-5.6) L/min/m(2), respectively. The median CI values that were calculated by PRAM before and after PLR were 2.5 (1.5-4.8) L/min/m(2) and 2.6 (1.7-5.7) L/min/m(2), respectively. There was significant correlations between the measured CI values both by TTE and PRAM before and after PLR (r=0.635, p=0.001 and r=0.610, p=0.001, respectively). The median percent changes in CI with TTE and PRAM were -0.13 (-0.7-0.4) and -0.11 (-0.5-0.5), respectively. Sixteen patients were determined as FR by TTE (64%) and 13 patients were determined as FR by PRAM (52%). The Kappa test showed moderate agreement between TTE and PRAM for predicting fluid responsiveness (k=0.595; p=0.002). The mean biases between the CI values measured by TTE and PRAM before and after PLR were 0.04 +/- 0.77 L/min/m(2) and 0.22 +/- 0.88 L/min/m(2), respectively.

Conclusion: This study showed a significant correlation for CI values measured by both methods. For predicting fluid responsiveness there was agreement between the two methods after PLR.