Fluid responsiveness predictability in immediate post-operative pediatric cardiac surgery. Is the old slandered CVP back again?

Objective: Acute low cardiac output (CO) is a frequent scenario in the pediatric cardiac intensive care unit (PCICU). While fluid responsiveness has been thoroughly studied, literature is scarce for the immediate post-operative congenital heart surgery population admitted to pediatric cardiac ICUs. The study analyzed the utility of hemodynamic, bedside ultrasound and Doppler parameters for prediction of fluid responsiveness in infants and neonates in the immediate postoperative cardiac surgery period.

Design: A prospective observational study.

Setting: University affiliated, tertiary care hospital, Pediatric cardiac intensive care unit.

Patients: Immediate post-operative pediatric patients displaying a presumed hypovolemic low CO state were included. A clinical, arterial derived, hemodynamic, sonographic, Doppler-based, and echocardiographic parameter assessment was performed, followed by a fluid bolus therapy.

Interventions: Crystalloid fluid bolus

Measurements: Fluid responsiveness was defined as an increase in cardiac Index >10% by echocardiography.

Results: Of 52 fluid boluses were assessed, 34 (65%) were fluid responsive. Arterial Systolic pressure variation (SPV), continuous-Doppler preload parameters, and inferior vena-cava distensibility index (IVCDI) by bedside ultrasound all failed to predict fluid responsiveness. Dynamic central venous pressure (CVP) change yielded a significant but moderate fluid responsiveness predictability of AUC 0.654 (p=0.0375).

Conclusions: In a distinct population of mechanically ventilated, young, pediatric cardiac patients in the immediate postoperative period, SPV, USCOM preload parameters, as well as IVC-based parameters by bedside ultrasound failed to predict fluid responsiveness. Dynamic CVP change over several hours was the only parameter that yielded significant but moderate fluid responsiveness predictability.