Haemolysis during cardiopulmonary bypass: an in vivo comparison of standard roller pumps, nonocclusive roller pumps and centrifugal pumps

Perfusion ◽  
1999 ◽  
Vol 14 (1) ◽  
pp. 3-10 ◽  
Author(s):  
S D Hansbro ◽  
D AC Sharpe ◽  
R Catchpole ◽  
K R Welsh ◽  
C M Munsch ◽  
...  

Cardiopulmonary bypass (CPB) involves the use of either an occlusive roller pump or centrifugal pump. Damage to blood elements, including haemolysis, may arise from occlusion when using a roller pump; the appropriate degree of occlusion has not yet been determined scientifically. Centrifugal and nonocclusive roller pumps are reputed to reduce haemolysis. The objective of this study was to compare haemolysis caused by a standard roller pump with a dynamically set nonocclusive roller pump and with a centrifugal pump. We prospectively randomized 60 patients undergoing routine coronary artery surgery into three groups: standard roller pump (STD, n = 20), dynamically set roller pump (DYN, n = 20), or centrifugal pump (CEN, n = 20). The level of plasma free haemoglobin (FHb) was measured preoperatively, and the rate of formation of FHb (in mg/dl/min) was determined at the end of the ischaemic phase and at the end of CPB. Cardiotomy suction blood was isolated for the ischaemic phase and returned before the end of CPB. It was found that there were no differences between the groups in demographic or operative variables. The rate of formation of FHb at the end of the ischaemic phase was similar for all groups (STD 0.108 ± 0.10, DYN 0.117 ± 0.08, CEN 0.129 ± 0.07). At the end of CPB, after return of the cardiotomy suction blood, there was a significant (<0.001) increase in the rate of formation of FHb in all groups. The increase was similar for each of the groups (STD 0.424 ± 0.17, DYN 0.481 ± 0.20, CEN 0.471 ± 0.18). We conclude that the rates of haemolysis are similar for each of the pump types, and no benefit is conferred by the use of either a dynamically set roller pump or a centrifugal pump compared with the standard roller pump. The return of the cardiotomy suction blood to the circulation is the principal source of plasma free haemoglobin.

1997 ◽  
Vol 20 (10) ◽  
pp. 562-569 ◽  
Author(s):  
T. Yamada ◽  
K. Nishimura ◽  
T. Akamatsu ◽  
T. Tsukiya ◽  
C.H. Park ◽  
...  

The life of currently-available centrifugal pumps is limited to no more than three days. As a magnetically suspended centrifugal pump (MSCP) contains no shaft or seal, it could be expected to have a longer life expectancy. The MSCP was evaluated in a chronic animal model using eight adult sheep. Left ventricular assist with the MSCP was instituted between the left atrium and the descending aorta. The flow rates ranged from 2.5 to 6.0 L/min. The duration of the experiments ranged from 14 to 60 days. No mechanical failure occurred. The plasma free hemoglobin levels remained within an acceptable range (3-19 mg/dL). No reduction in the counts of red blood cells or platelets was observed. Thrombus formation within the MSCP was recognized in one pump. The main reason for termination was thromboembolism derived from the circuits. Three types of regulation methods (constant rotational speed, constant motor current, and controlled motor current) were also investigated. Regulation by a constant motor current mode altered the pressure-flow (P-Q) characteristics, and thereby, a steadier pump flow was obtained compared with regulation in the constant rotational speed mode. Moreover, the controlled motor current mode can change the P-Q relationship. These results demonstrate that the MSCP is a promising device for long-term use.


2001 ◽  
Vol 15 (3) ◽  
pp. 322-325 ◽  
Author(s):  
David A. Scott ◽  
Brendan S. Silbert ◽  
Carolyn Blyth ◽  
Jennifer O'Brien ◽  
John Santamaria

1998 ◽  
Vol 34 (6) ◽  
pp. 1208
Author(s):  
Mi Sook Gwak ◽  
Chung Su Kim ◽  
Gaab Soo Kim ◽  
Yu Hong Kim ◽  
Kay Hyun Park ◽  
...  

1999 ◽  
Vol 88 (Supplement) ◽  
pp. 89S
Author(s):  
J.A. Lieberman ◽  
S. Tammineedi ◽  
J. Aukerman

Perfusion ◽  
1986 ◽  
Vol 1 (4) ◽  
pp. 261-269 ◽  
Author(s):  
Lynda L Mickleborough ◽  
George Arnold ◽  
Ray C-J Chiu

The purpose of this study was to compare levels of C3 and C4 during cardiopulmonary bypass, using bubble and membrane oxygenators. In vitro studies were performed using human blood in a simple circuit involving an oxygenator, roller pump and connector tubing. In vivo studies were carried out in two separate institutions using a variety of bubble and membrane oxygenators. Samples were taken throughout the pump run (30-1 20 minutes). Complement levels were corrected for haemodilution. All oxygenators tested caused a rapid decrease in C3 and C4 complement levels on institution of bypass. The magnitude and timing of these decreases were similar in the membrane and bubble groups. Thereafter, complement levels were stable throughout the pump run. These data do not suggest that there is any difference in complement activation during relatively short pump runs using bubble and membrane oxygenators.


Perfusion ◽  
1994 ◽  
Vol 9 (2) ◽  
pp. 109-117 ◽  
Author(s):  
Oddvar Moen ◽  
Erik Fosse ◽  
Jennifer Bråten ◽  
Conny Andersson ◽  
Magne K. Fagerhol ◽  
...  

A Biomedicus centrifugal pump and a Polystan roller pump were compared in vitro with regard to differences in haemolysis, granulocyte and complement activation. Six circuits of tubing and oxygenators were connected to each pump. Heparinized fresh human blood was circulated for 72 hours in the systems. Blood samples were drawn at defined intervals. Haemolysis was assessed by determination of lactate dehydrogenase (LD) and potassium, and granulocyte activation by quantification of the granulocyte proteins calprotectin, lactoferrin and myeloperoxidase. Complement activation was assessed by measuring C3 activation products (C3b, iC3b and C3c), and the terminal C5b-9 complement complex (TCC). The results indicate more haemolysis and complement activation in the roller pump group, revealed by significantly higher concentrations of LD, potassium, C3 activation products and TCC. Calprotectin, lactoferrin and myeloperoxidase were all significantly increased in both groups, but the rise appeared earlier in the roller pump group. The concentrations of LD and potassium both correlated significantly with C3 activation products, indicating that complement activation may at least partly be responsible for the haemolysis.


2017 ◽  
Vol 40 (3) ◽  
pp. 118-122 ◽  
Author(s):  
Francisco U. Vieira Junior ◽  
Nilson Antunes ◽  
Pedro P. de Oliveira ◽  
Lindemberg M. Silveira Filho ◽  
Karlos A.S. Vilarinho ◽  
...  

Introduction Roller pumps are widely used in procedures involving cardiopulmonary bypass (CPB) due to their ease of operation and maintenance, safety, and cost. Several studies in the literature have compared the use of roller pumps with centrifugal pumps, but the influence of the roller pump adjustment on hemolysis has been poorly explored. Methods Measurements of hemolysis rates were carried out in 86 patients. The pump was adjusted by the dynamic calibration method, which was performed by an auxiliary device, and the patients were grouped according to the pump calibration: Group 1 (n = 20) 75 mmHg; Group 2 (n = 24) 150 mmHg; Group 3 (n = 22) 300 mmHg and Group 4 (n = 21) 450 mmHg. The hemolysis rates were measured at 4 different times during CPB (TO: before the surgical procedure; T1: 5 minutes after the start of CPB; T2: 30 minutes of CPB; and T3: 5 minutes after the CPB procedure). Hemolysis rates were calculated between the time intervals T0–T1, T1–T2, and T0–T3. Results No difference in hemolysis rates was observed between the groups (p>0.31). During the first 5 minutes of CPB, hemolysis represented 35.5% of the total hemolysis and no significant difference was found between groups (p>0.60). Conclusions Calibration of roller pumps by the dynamic method did not influence the hemolysis rates. Additionally, the hemolysis during the first 5 minutes of CPB accounted for ∼1/3 of the total hemolysis.


2018 ◽  
Vol 1 (2) ◽  
pp. 24-39
Author(s):  
A. Farid ◽  
A. Abou El-Azm Aly ◽  
H. Abdallah

Cavitation in pumps is the most severe condition that centrifugal pumps can work in and is leading to a loss in their performance.  Herein, the effect of semi-open centrifugal pump side clearance on the inception of pump cavitation has been investigated.  The input pump pressure has been changed from 80 to 16 kPa and the pump side clearance has been changed from 1 mm to 3 mm at a rotation speed of 1500 rpm. It has been shown that as the total input pressure decreased; the static pressure inside the impeller is reduced while the total pressure in streamwise direction has been reduced, also the pump head is constant with the reduction of the total input pressure until the cavitation is reached. Head is reduced due to cavitation inception; the head is reduced in the case of a closed impeller with a percent of 1.5% while it is reduced with a percent of 0.5% for pump side clearance of 1mm, both are at a pressure of 20 kPa.   Results also showed that the cavitation inception in the pump had been affected and delayed with the increase of the pump side clearance; the cavitation has been noticed to occur at approximate pressures of 20 kPa for side clearance of 1mm, 18 kPa for side clearances of 2mm and 16 kPa for 3mm.


Author(s):  
Weihui Xu ◽  
Xiaoke He ◽  
Xiao Hou ◽  
Zhihao Huang ◽  
Weishu Wang

AbstractCavitation is a phenomenon that occurs easily during rotation of fluid machinery and can decrease the performance of a pump, thereby resulting in damage to flow passage components. To study the influence of wall roughness on the cavitation performance of a centrifugal pump, a three-dimensional model of internal flow field of a centrifugal pump was constructed and a numerical simulation of cavitation in the flow field was conducted with ANSYS CFX software based on the Reynolds normalization group k-epsilon turbulence model and Zwart cavitation model. The cavitation can be further divided into four stages: cavitation inception, cavitation development, critical cavitation, and fracture cavitation. Influencing laws of wall roughness of the blade surface on the cavitation performance of a centrifugal pump were analyzed. Research results demonstrate that in the design process of centrifugal pumps, decreasing the wall roughness appropriately during the cavitation development and critical cavitation is important to effectively improve the cavitation performance of pumps. Moreover, a number of nucleation sites on the blade surface increase with the increase in wall roughness, thereby expanding the low-pressure area of the blade. Research conclusions can provide theoretical references to improve cavitation performance and optimize the structural design of the pump.


Machines ◽  
2021 ◽  
Vol 9 (3) ◽  
pp. 60
Author(s):  
Khaled Alawadhi ◽  
Bashar Alzuwayer ◽  
Tareq Ali Mohammad ◽  
Mohammad H. Buhemdi

Since centrifugal pumps consume a mammoth amount of energy in various industrial applications, their design and optimization are highly relevant to saving maximum energy and increasing the system’s efficiency. In the current investigation, a centrifugal pump has been designed and optimized. The study has been carried out for the specific application of transportation of slurry at a flow rate of 120 m3/hr to a head of 20 m. For the optimization process, a multi-objective genetic algorithm (MOGA) and response surface methodology (RSM) have been employed. The process is based on the mean line design of the pump. It utilizes six geometric parameters as design variables, i.e., number of vanes, inlet beta shroud, exit beta shroud, hub inlet blade draft, Rake angle, and the impeller’s rotational speed. The objective functions employed are pump power, hydraulic efficiency, volumetric efficiency, and pump efficiency. In this reference, five different software packages, i.e., ANSYS Vista, ANSYS DesignModeler, response surface optimization software, and ANSYS CFX, were coupled to achieve the optimized design of the pump geometry. Characteristic maps were generated using simulations conducted for 45 points. Additionally, erosion rate was predicted using 3-D numerical simulations under various conditions. Finally, the transient behavior of the pump, being the highlight of the study, was evaluated. Results suggest that the maximum fluctuation in the local pressure and stresses on the cases correspond to a phase angle of 0°–30° of the casing that in turn corresponds to the maximum erosion rates in the region.


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