Artificial organs
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Extracorporeal membrane oxygenation (ECMO) for respiratory failure was reviewed. ECMO progressed from laboratory research to initial clinical trials in 1972. Following a decade of clinical research, ECMO is now standard treatment for neonatal respiratory failure refractory to conventional pulmonary support techniques worldwide. ⋯ As of July 1994, 9,258 neonates, 754 pediatric, and 130 adult patients with respiratory failure treated with ECMO were entered in the registry of the Extracorporeal Life Support Organization (ELSO). Overall survival rates were 81% in neonates, 49% in pediatric, and 38% in adult patients. Recently the adult and pediatric populations treated with ECMO have increased rapidly, and the outcome has improved significantly.
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Clinical Trial
Double balloon catheter for concomitant augmentation of abdominal organ perfusion during intraaortic balloon counterpulsation.
A newly devised double balloon catheter to augment abdominal organ perfusion concomitant with original cardiac assist during intraaortic balloon counterpulsation provided satisfactory hemodynamics and urinary output around cardiac surgical procedures in 2 patients with coronary artery disease. Some optional advantages in clinical application and problems arising in the catheter design which need to be investigated are discussed.
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Comparative Study
The inferior vena cava diameter as a marker of dry weight in chronic hemodialyzed patients.
We have previously reported that the diameter of the inferior vena cava (IVC) reflects the amount of body fluid in hemodialyzed (HD) patients. The present study was undertaken to depict the criteria of IVC diameters for determining dry weight (DW) in anuric HD patients. In healthy subjects, the maximal diameters during quiet expiration (IVCe) and the minimal diameters during quiet inspiration (IVCi) were 16.7 +/- 3.2 and 5.7 +/- 5.4 mm, respectively (mean +/- SD). ⋯ IVCe decreased proportionally to the amount of ultrafiltration. In HD patients with hypervolemic pulmonary edema, the IVCe and CI values were 22.4 +/- 2.9 and 0.22 +/- 0.11, respectively. We proposed that IVCe/CI after HD is 8 +/- 3 mm/0.9 +/- 0.1 as the markers of DW in anuric HD patients and that an IVCe value > or = 22 mm together with a CI < or = 0.22 implies the warning level of body fluid retention.
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To analyze the hemodynamic parameters during circulation with oscillated blood flow, nonlinear mathematical analyzing techniques, including fractal theory, were utilized. Vibrating flow pumps (VFP) were implanted as a left heart bypass, and the ascending aorta was clamped to constitute the total left heart circulation with oscillated blood flow in acute animal experiments using 7 adult goats. ⋯ During VFP bypass, lower fractal dimensions of the reconstructed attractor were shown compared with those during natural heart circulation. The results suggest that lower dimensional chaotic dynamics contributed to the circulation with oscillated blood flow.
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The effects of pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) and other hemoglobin-related substances on arterial blood pressure (ABP) and heart rate (HR) were examined. Infusion of PHP and other hemoglobin-related substances elevated ABP and increased HR. The degree of the increase in ABP and HR did not differ among the groups. ⋯ PHP also elevated ABP in conscious rats. The magnitude of the ABP elevation was significantly smaller than in the anesthetized rats. Results indicate that inhibition of nitric oxide (NO) might be responsible in part for the elevation of ABP, and the degree of the elevation would be dependent on the degree of contribution of NO to the regulation of ABP.