Monitoring the correlation between passive leg-raising maneuver and fluid challenge in pediatric cardiac surgery patients using impedance cardiography

Abstract

Aim The aim of the study was to highlight the effectiveness of passive leg-raising maneuver as a predictor of fluid responsiveness in pediatric patients following cardiac surgery and to determine the parameter that we can depend on to assess its responsiveness. Patients and methods This prospective randomized study was performed in the ICU. Forty pediatric patients aged 2-7 years with a noncyanotic cardiac defect scheduled for elective corrective cardiac surgery under cardiopulmonary bypass (CPB) support were included if they needed fluid challenge (FC) in the early postoperative period (10 ml/kg normal saline infusion). Hemodynamic parameters [heart rate, mean blood pressure, stroke volume (SV), and cardiac index (CI)] were assessed at baseline, after passive leg raising (PLR), at baseline again, and after FC. Statistical analysis A comparison of pre-PLR and post-PLR hemodynamic parameters and those before and after FC was made using the paired Student's t-test, whereas a comparison after passive leg raising (PLR) and FC was made using the unpaired Student's t-test. The hemodynamic parameters after PLR and its relation to the responses to fluid administration were analyzed using diagnostic validity tests and the χ2 -test. Results The increase in SV and CI with PLR is significantly correlated with the response to fluid administration. An increase in CI by 10% or more due to PLR predicted preload-dependent status with a sensitivity of 65% and a specificity of 75%, whereas an increase in SV by more than 10% due to PLR predicted preload-dependent status with a sensitivity of 42.1% and a specificity of 85.7%. Conclusion The PLR maneuver is a reliable noninvasive method that can predict volume responsiveness in post-cardiac-surgery pediatric patients. Both SV and CI can be used as predictors of fluid responsiveness, although CI is a more accurate.