Clinical application of electrical velocimetry in monitoring pediatric blood volume after cardiopulmonary bypass

Abstract

Objective: To investigate the clinical applicability of electrical velocimetry (EV) in monitoring pediatric blood volume after cardiopulmonary bypass. Method: Between July 2016 and November 2016, 60 children with congenital heart disease were divided into EV group and traditional central venous pressure (CVP) group randomly. For EV group, the volume of fluid and vascular active medicine was adjusted according to the monitoring stroke volume variation (SVV) hemodynamic parameters. Whereas for CVP group empirical volume of fluid infusion was managed by the monitoring traditional hemodynamic parameters such as CVP, blood pressure, heart rate, urine volume and blood gas analysis.Heart rate (HR), mean artery pressure (MAP), blood lactic acid (LA), oxygenation index (PaO(2)/FiO(2)) at 2, 4 and 6 h after operation were observed and compared between two groups. Mechanical ventilation time and ICU monitoring time were also compared between two groups. Pearson correlation analysis was performed to investigate the significance of SVV and inferior vena cava expansion index (dIVC) for evaluating of reactivity capacity after surgery. Result: MAP level was significantly higher in EV group at 2, 4, and 6 h after operation [ (62±10) vs. (50±6) mmHg(1 mmHg=0.133 kPa), (68±11) vs.(59±4) mmHg, (71±6) vs. (63±8) mmHg respectively; t=5.580 9, 4.530 1, 4.308 1; P=0.001, 0.002, 0.001]. PaO(2)/FiO(2) ratio was higher in EV group than that of CVP group[ (362±23) vs. (310±43), (380±33) vs. (330±38), (386±57) vs. (350±63.1) respectively, t=5.818 8, 5.419 2, 2.317 2; P=0.002, 0.001, 0.024]. However HR and blood lactic acid level was lower in EV group than the CVP group [(166±10) vs. (179±14)/min, (156±11) vs. (168±16)/min, (138±10) vs. (149±13)/min respectively; t=3.930 7, 3.511 1, 3.671 5; P=0.002, 0.009, 0.005]; [7% vs. 33%, 3% vs. 20%, 0 vs. 13%, χ(2)=5.104 2、4.043 1、4.285 7, P=0.045 3, 0.044 4, 0.038 4] respectively; Mechanical ventilation time [ (4.3±0.7) vs. (8.2±0.8) h, P=0.008] and ICU monitoring time [ (16.4±3.2) vs. (21.2±2.6) h,P=0.003] was shorter in EV group than that in group CVP. Pearson correlation analysis suggested that the SVV and dIVC have significant positive correlation. Conclusion: SVV monitoring using EV could help to guide perioperative fluid management for children with congenital heart disease. Real time dynamic monitoring SVV improves liquid infusion management more timely, accurately, and avoids excessive or insufficient blood volume load which is associated with leading to organ dysfunction.