Blood Trauma Induced by Clinically Accepted Oxygenators

Kawahito, S.; Maeda, Takeshi; Takano, T.; Nonaka, Kenji; Linneweber, Joerg; Schulte-Eistrup, S.; Sato, Teruko; Mikami, Masayuki; Glueck, Julie; Nosé, Y.

doi:10.1097/00002480-200003000-00131

Cited by 3 publications

(3 citation statements)

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“…where Δ fHb is the measured increase in plasma‐free hemoglobin concentration (g/L) during the test period, Δ t represents the duration of the test period (min), Ht denotes the hematocrit (%), V corresponds to the blood volume in the test circuit (L), and Q signifies the flow rate (L/min). This equation is employed in designing heart pumps as well as other blood‐contacting medical devices, such as oxygenators and dialyzers (22,23). The in vitro NIH values can be related to the blood damage index according to the following equation (24):…”

Section: Methodsmentioning

confidence: 99%

Intravascular Mechanical Cavopulmonary Assistance for Patients With Failing Fontan Physiology

et al. 2009

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To provide a viable bridge-to-transplant, bridgeto-recovery, or bridge-to-surgical reconstruction for patients with failing Fontan physiology, we are developing a collapsible, percutaneously inserted, magnetically levitated axial flow blood pump to support the cavopulmonary circulation in adolescent and adult patients. This unique blood pump will augment pressure and thus flow in the inferior vena cava through the lungs and ameliorate the poor hemodynamics associated with the univentricular circulation. Computational fluid dynamics analyses were performed to create the design of the impeller, the protective cage of filaments, and the set of diffuser blades for our axial flow blood pump. These analyses included the generation of pressure-flow characteristics, scalar stress estimations, and blood damage indexes. A quasi-steady analysis of the diffuser rotation was also completed and indicated an optimal diffuser rotational orientation of approximately 12°. The numerical predictions of the pump performance demonstrated a pressure generation of 2-25 mm Hg for 1-7 L/min over 3000-8000 rpm. Scalar stress values were less than 200 Pa, and fluid residence times were found to be within acceptable ranges being less than 0.25 s. The maximum blood damage index was calculated to be 0.068%. These results support the continued design and development of this cavopulmonary assist device, building upon previous numerical work and experimental prototype testing. Key Words: Ventricular assist device(s)-Single ventricle physiology-Cavopulmonary assist device-Fontan conversion-Heart pump-Blood pump-Artificial right ventricle-Pediatric circulatory support-Intravascular blood pump-Mechanical cavopulmonary assist.Pediatric cardiovascular malformations contribute to 6-10% of all infant deaths and are one of the two leading causes of neonatal death. These malformations occur in approximately one to eight of every 1000 live births with a significant incidence of one in six infants being born preterm (1,2). The occurrence of multiple and significant cardiac malformations, such as tricuspid atresia and hypoplastic left heart syndrome, requires corrective surgery (3,4). The only chance of survival for these patients is the threestaged surgical palliative procedure known as the Fontan procedure, which results in the patients having a single functional ventricle to drive blood flow through the systemic and pulmonary circulations.Care must be taken in operating on these infants at such a short time after birth since the pulmonary vascular beds are reactive from prenatal stages of development and may induce elevated vascular resistance by contractions of smooth muscle lining. The first operation, known as the Norwood procedure, provides blood flow to the lungs through an artery-topulmonary-artery shunt. This operation occurs within 2 weeks of age. After the risk of elevated pulmonary vascular resistance has decreased, the conversion is continued with the second stage known as the Glenn, in which the Norwood shunt is disconnected and the superior v...

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Section: Methodsmentioning

confidence: 99%

Intravascular Mechanical Cavopulmonary Assistance for Patients With Failing Fontan Physiology

et al. 2009

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“…also found no significant correlation between the pressure gradient and hemolysis, whereas Kawahito et al. showed a trend of increased hemolysis with increased pressure drop (17,18). Although in contrast to the findings of Kawahito et al., but in line with those of Segers et al.…”

Section: Discussionmentioning

confidence: 71%

Pulse Conductance and Flow‐induced Hemolysis During Pulsatile Cardiopulmonary Bypass

et al. 2010

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In this study, the hypothesis was tested that a low-resistant, high-compliant oxygenator provides better pulse conductance and less hemolysis than a high-resistant, low-compliant oxygenator during pulsatile cardiopulmonary bypass. Forty adults undergoing coronary artery bypass surgery were randomly divided into two groups using either an oxygenator with a relatively low hydraulic resistance (Quadrox BE-HMO 2000, Maquet Cardiopulmonary AG, Hirrlingen, Germany) or with a relatively high hydraulic resistance (Capiox SX18, Terumo Cardiovascular Systems, Tokyo, Japan). The phase shift between the flow signals measured at the inlet and outlet of the oxygenator was used to assess compliance. Pulse conductance in terms of pressure attenuation was calculated by dividing the outlet pulse pressure of the oxygenator by the inlet pulse pressure. A normalized index was used to assess hemolysis. The phase shifts in time of the flow pulses were 36 +/- 6 ms in the low-resistant (high-compliant) oxygenator, and 14 +/- 2 ms in the high-resistant (low-compliant) oxygenator group (P < 0.001). The low-resistant, high-compliant oxygenator provided 27% better pulse conductance compared with the high-resistant, low-compliant oxygenator (0.84 +/- 0.02 and 0.66 +/- 0.01, respectively, P < 0.001). Inlet pulse pressures were significantly higher (29%) in the high-resistant, low-compliant (Capiox) group than in the low-resistant, high-compliant (Quadrox) group (838 +/- 38 mm Hg and 648 +/- 25 mm Hg respectively, P < 0.001), but no significant difference in hemolysis was found. A low-resistant, high-compliant oxygenator provides better pulse conduction than a high-resistant, low-compliant oxygenator. However, the study data could not confirm the association of high pressures with increased hemolysis.

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“…In the surgical patient, hemolysis is frequently produced by various hemolytic reactions (e.g. mismatched transfused blood), as well as pump oxygenator trauma to red blood cells during cardiopulmonary bypass (Kawahito et al 2001). …”

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confidence: 99%

Hemoglobin-Based Red Blood Cell Substitutes and Nitric Oxide

Bloch

Zapol

2009

Trends in Cardiovascular Medicine

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Hemoglobin-based oxygen carriers (HBOCs) have been studied for decades as red blood cell substitutes. Profound vasoconstrictor effects have limited the clinical utility of HBOCs and are attributable to avid scavenging of nitric oxide (NO). Inhaling NO can charge the body's stores of NO metabolites without producing hypotension and can prevent systemic hypertension induced when HBOCs are subsequently infused. Concurrent breathing of low NO doses can prevent pulmonary vasoconstriction after HBOC infusion without augmenting plasma methemoglobinemia.

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Blood Trauma Induced by Clinically Accepted Oxygenators

Cited by 3 publications

References 0 publications

Intravascular Mechanical Cavopulmonary Assistance for Patients With Failing Fontan Physiology

Intravascular Mechanical Cavopulmonary Assistance for Patients With Failing Fontan Physiology

Pulse Conductance and Flow‐induced Hemolysis During Pulsatile Cardiopulmonary Bypass

Hemoglobin-Based Red Blood Cell Substitutes and Nitric Oxide

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