Comparision of Cardiac Output Measured by Transthoracic Echocardiography with Continuous Cardiac Output Measured by Pressure Recording Analytical Method

Background: Low cardiac output is a common complication following cardiac surgery and it is associated with higher mortality in the pediatric population. A gold standard method for cardiac output (CO) monitoring in the pediatric population is lacking. The present study was conducted to validate cardiac output and cardiac index measured by transthoracic echocardiography and Pressure recording analytical method, a continuous pulse contour method, MostCare(Up) in postoperative pediatric cardiac surgical patients. Materials and Methods: This was a prospective observational clinical study conducted at a tertiary care hospital. A total of 23 pediatric patients weighed between 2 and 20 kg who had undergone elective cardiac surgery were included in the study. Results: Spearman's correlation coefficient of CO between transthoracic echocardiography (TTE) and Pressure Recording Analytical Method (PRAM) showed of positive correlation (r = 0.69, 95% Confidence interval 0.59-0.77, P < 0.0001) Linear regression equations for CO between TTE and PRAM were y = 0.55 + 0.88x (R-2 = 0.46, P < 0.0001). (y = PRAM, x = TTE), respectively. Bland- Altman plot for CO between TTE and PRAM showed a bias of -0.397 with limits of the agreement being -2.01 to 1.22. Polar plot analysis showed an angular bias of 6.55 degrees with radial limits of the agreement being -21.46 to 34.58 for CO and angular bias of 6.22 degrees with radial limits of the agreement being -22.4 to 34.84 for CI. Conclusion: PRAM has shown good trending ability for cardiac output. However, values measured by PRAM are not interchangeable with the values measured by transthoracic echocardiography.