Comparative Effects of Pulsatile and Nonpulsatile Flow on Plasma Fibrinolytic Balance in Pediatric Patients Undergoing Cardiopulmonary Bypass

Abstract

In the brain, the components of the fibrinolytic system, tissue plasminogen activator (tPA) and its endogenous inhibitor plasminogen activator inhibitor-1 (PAI-1), regulate various neurophysiological and pathological responses. Fibrinolytic balance depends on PAI-1 and tPA concentrations. The objective of this study is to compare the effects of pulsatile and nonpulsatile perfusion on fibrinolytic balance in children undergoing pediatric cardiopulmonary bypass (CPB). Plasma PAI-1 antigen and tPA antigen were measured in 40 children (n = 20 pulsatile and n = 20 nonpulsatile group). Plasma samples (1.5 mL) were collected (i) prior to incision, (ii) 1 h after CPB, and (iii) 24 h after CPB. PAI-1 and tPA levels were measured at each time point. PAI-1 and tPA levels were significantly increased at 1 h after CPB, followed by a decrease at 24 h. Nonpulsatile but not pulsatile CPB lowered PAI-1 : tPA ratio significantly at 24 h (median PAI-1 : tPA ratio 4.63 ± 0.83:1.98 ± 0.48, P = 0.03, for the nonpulsatile group and 4.50 ± 0.92:3.56 ± 1.28, P = 0.2, for the pulsatile group). These results suggest that pulsatile flow maintains endogenous fibrinolytic balance after pediatric cardiopulmonary bypass. Further studies are needed to define the clinical significance of these differences.

Evaluation of a Novel Pulsatile Extracorporeal Life Support System Synchronized to the Cardiac Cycle: Effect of Rhythm Changes on Hemodynamic Performance

“…There is mounting evidence that pulsatile flow may reduce some of the complications related to extracorporeal circulation by improving vital organ microcirculation and reducing the need for inotropes (7)(8)(9). Multiple studies of cardiopulmonary bypass and ventricular assist device support have shown the benefits of pulsatile flow (10)(11)(12)(13)(14)(15). Synchronizing pulsatile ECLS to the patient's intrinsic rhythm may have additional clinical benefit as the delivered pulsatility would not compete with the patient's intrinsic cardiac systolic performance.…”

Microfluidics contrasted to thrombelastography: perplexities in defining hypercoagulability

“…15 This raises concerns for the comparability of TEG to T-TAS, as dilution and variance in viscosity complicate differences between the stagnant and flow conditions. 40,41 Another limitation of our study is the inherent qualitative difference of the LY30 metric in relation to T-TAS’s settings for both PL and AR chips. In TEG, LY30 is a measurement obtained after MA is reached, but T-TAS stops running its assay before an MA or LY30 equivalent is measured as T-TAS’s design includes a preset pressure ceiling to stop running the assay at ~80 kPa for the AR chip and ~60 kPa for the PL chip.…”

Impact of Pulsatile Flow on Vital Organ Recovery During Cardiopulmonary Bypass in Neonates and Infants

“…tPA and PAI-1 regulate various neurophysiological and pathological responses in the brain. In a prospective study, we compared the effects of pulsatile and nonpulsatile perfusion on tPA and PAI-1 levels in 40 children undergoing CPB, and found that the pulsatile group had lower PAI-1 levels and PAI-1 : tPA molar ratios at 24 h following CPB procedure (27). The results suggest that pulsatile flow maintains endogenous fibrinolytic balance after pediatric CPB.…”

“…In a prospective study, we compared the effects of pulsatile and nonpulsatile perfusion on tPA and PAI-1 levels in 40 children undergoing CPB, and found that the pulsatile group had lower PAI-1 levels and PAI-1 : tPA molar ratios at 24 h following CPB procedure (27). tPA and PAI-1 regulate various neurophysiological and pathological responses in the brain.…”