Pulsatile and nonpulsatile cardiopulmonary bypass: review of a counterproductive controversy.

Primary repair of interrupted aortic arch and severe aortic stenosis in neonates.

Brain tissue pH, oxygen tension, and carbon dioxide tension in profoundly hypothermic cardiopulmonary bypass. Comparative study of circulatory arrest, nonpulsatile low-flow perfusion, and pulsatile low-flow perfusion.

Several clinical and animal studies have demonstrated that pulsatile perfusion is more beneficial than nonpulsatile perfusion during short or long durations of extracorporeal circulation. Other investigators, however, have been unable to document these benefits. The issue remains controversial. Central to the debate is the issue of a precise definition of pulsatile flow. To help resolve the conflict, pulsatile flow may be quantified in terms of energy equivalent pressure. This formula contains both the arterial pressure and pump flow rate, which are the 2 most critical parameters for open heart surgery. This definition establishes common criteria for assessment of the effectiveness of extracorporeal support.

Defining Pulsatile Perfusion: Quantification in Terms of Energy Equivalent Pressure

Controversy over benefits of pulsatile flow after pediatric cardiopulmonary bypass (CPB) continues. Our study objectives were to first, quantify pressure and flow waveforms in terms of hemodynamic energy, using the energy equivalent (EEP) formula, for direct comparisons, and second, investigate effects of pulsatile versus nonpulsatile flow on cerebral and renal blood flow, and cerebral vascular resistance during and after CPB with deep hypothermic circulatory arrest (DHCA) in a neonatal piglet model. Fourteen piglets underwent perfusion with either an hydraulically driven dual-chamber physiologic pulsatile pump (P, n = 7) or a conventional nonpulsatile roller pump (NP, n = 7). The radiolabeled microsphere technique was used to determine the cerebral and renal blood flow. P produced higher hemodynamic energy (from mean arterial pressure to EEP) compared to NP during normothermic CPB (13 +/- 3% versus 1 +/- 1%, p < 0.0001), hypothermic CPB (15 +/- 4% versus 1 +/- 1%, p < 0.0001) and after rewarming (16 +/- 5% versus 1 +/- 1%, p < 0.0001). Global cerebral blood flow was higher for P compared to NP during CPB (104 +/- 12 ml/100g/min versus 70 +/- 8 ml/100g/min, p < 0.05). In the right and left hemispheres, cerebellum, basal ganglia, and brainstem, blood flow resembled the global cerebral blood flow. Cerebral vascular resistance was lower (p < 0.007) and renal blood flow was improved fourfold (p < 0.05) for P versus NP, after CPB. Pulsatile flow generates higher hemodynamic energy, enhancing cerebral and renal blood flow during and after CPB with DHCA in this model.

Pediatric physiologic pulsatile pump enhances cerebral and renal blood flow during and after cardiopulmonary bypass.

Pulsatile perfusion versus conventional high-flow nonpulsatile perfusion for rapid core cooling and rewarming of infants for circulatory arrest in cardiac operation

Williams Gd

Papers

Pulsatile perfusion versus conventional high-flow nonpulsatile perfusion for rapid core cooling and rewarming of infants for circulatory arrest in cardiac operation