The Effect of Pulsatile Versus Nonpulsatile Blood Flow on Viscoelasticity and Red Blood Cell Aggregation in Extracorporeal Circulation.
BACKGROUND
Extracorporeal circulation (ECC) can induce alterations in blood viscoelasticity and cause red blood cell (RBC) aggregation. In this study, the authors evaluated the effects of pump flow pulsatility on blood viscoelasticity and RBC aggregation.


METHODS
Mongrel dogs were randomly assigned to two groups: a nonpulsatile pump group (n=6) or a pulsatile pump group (n=6). After ECC was started at a pump flow rate of 80 mL/kg/min, cardiac fibrillation was induced. Blood sampling was performed before and at 1, 2, and 3 hours after ECC commencement. To eliminate bias induced by hematocrit and plasma, all blood samples were adjusted to a hematocrit of 45% using baseline plasma. Blood viscoelasticity, plasma viscosity, hematocrit, arterial blood gas analysis, central venous O2 saturation, and lactate were measured.


RESULTS
The blood viscosity and aggregation index decreased abruptly 1 hour after ECC and then remained low during ECC in both groups, but blood elasticity did not change during ECC. Blood viscosity, blood elasticity, plasma viscosity, and the aggregation index were not significantly different in the groups at any time. Hematocrit decreased abruptly 1 hour after ECC in both groups due to dilution by the priming solution used.


CONCLUSIONS
After ECC, blood viscoelasticity and RBC aggregation were not different in the pulsatile and nonpulsatile groups in the adult dog model. Furthermore, pulsatile flow did not have a more harmful effect on blood viscoelasticity or RBC aggregation than nonpulsatile flow.
Department of Molecular Medicine, Gachon University Graduate School of Medicine.
Chi Bum
CB
Ahn
Department of Mechatronics, Gwangju Institute of Science and Technology.
Yang Jun
YJ
Kang
Department of Mechatronics, Gwangju Institute of Science and Technology.
Myoung Gon
MG
Kim
Department of Mechatronics, Gwangju Institute of Science and Technology.
Sung
S
Yang
Department of Anesthesiology and Pain Medicine, Korea University Medical Center.
Choon Hak
CH
Lim
Department of Thoracic and Cardiovascular Surgery, Korea University Medical Center.
Ho Sung
HS
Son
Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University College of Medicine.
Ji Sung
JS
Kim
Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University College of Medicine.
So Young
SY
Lee
Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University College of Medicine.
Kuk Hui
KH
Son
Department of Thoracic and Cardiovascular Surgery, Korea University Medical Center.
Kyung
K
Sun
Blood; Cardiopulmonary bypass; Extracorporeal circulation; Hematology