Artificial organs
-
Comparative Study
The impact of polyethylene glycol conjugation on bovine hemoglobin's circulatory half-life and renal effects in a rabbit top-loaded transfusion model.
This study compares the effects of polyethylene glycol (PEG) modified bovine hemoglobin on vascular half-life and renal function in rabbits to those of unmodified bovine hemoglobin. Renal function was assessed by the measurement of the glomerular filtration rate, urinalysis, blood chemistries, hemoglobin (Hb) excretion rates, and tissue histology. The influence of infusion rates on hemoglobin excretion rates and organ morphology was also examined. ⋯ However, unmodified bovine hemoglobin did demonstrate significant hemoglobinuria (Hb excretion levels in excess of 1.0% of the infused dose [p < 0.05]) at all infusion rates given while PEG modified bovine hemoglobin did not. In addition, histological examination by light microscopy indicated that the most severe morphological changes occurred in animals that received unmodified bovine hemoglobin. This data suggests that PEG modification of bovine hemoglobin significantly reduced some of the adverse effects of bovine hemoglobin on renal physiology and morphology.
-
Case Reports Comparative Study Clinical Trial Controlled Clinical Trial
Clinical evaluation of pulsatile flow mode of Terumo Capiox centrifugal pump.
The Terumo Capiox centrifugal pump system possesses an automatic priming function in which the motor repeatedly stops and runs intermittently to eliminate air bubbles in the circuit through the micropores of the hollow-fiber membrane oxygenator. By modifying this mechanism, we have developed a pulsatile flow mode. In this mode, maximum and minimum pump rotational speeds can be independently set every 20 rpm in the range of 0 to 3,000 rpm. ⋯ The pulse pressure obtained with the Delphin pump was not more than that obtained with the Terumo pump. There were no significant differences in percents of preoperative levels of platelet counts (pulsatile, 87.6 +/- 15.8% and nonpulsatile, 72.4 +/- 40.6%), free hemoglobin (pulsatile, 18 +/- 8 mg/dl and nonpulsatile, 25 = 7 mg/dl), and beta-TG (pulsatile 298 +/- 28 ng/ml and nonpulsatile, 312 +/- 143 ng/ml). In conclusion, although the pulsatile mode of the Terumo centrifugal pump did not exhibit any adverse effects hematologically, the pulse pressure obtained was unsatisfactorily small, mainly because of dumping caused by the perfusion cannula.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Biocompatibility of heparin-coated circuits in pediatric cardiopulmonary bypass.
In this study, we evaluated the biocompatibility of heparin-coated circuits in pediatric cardiopulmonary bypass (CPB). Eight patients were divided into 2 groups: the control group (Group C) and heparin-coated group (Group H). In Group H, CPB circuits, including the arterial pump, oxygenator, and cannulas were heparin-coated. ⋯ There was no significant difference in Plat, PIC, or TAT between groups. Group H showed significantly low levels of C3a (during and after CPB), PMN elastase (during CPB), and IL-6 (after CPB). These data demonstrated that in pediatric CPB, heparin-coated CPB circuits reduced the activation of complements and the production of PMN elastase and IL-6, suggesting the superior biocompatibility of the heparin-coated circuits.
-
Comparative Study
A newly developed silicone-coated membrane oxygenator for long-term cardiopulmonary bypass and cardiac support.
The surface of polypropylene hollow fiber was successfully coated with a very thin (0.2 micron) silicone layer. Experimental studies were performed in long-term (6 h) normothermic cardiopulmonary bypass (CPB) using 10 goats. A conventional membrane oxygenator (Mera Excelung HPO-15H, MERA, Tokyo, Japan) was used for 5 goats as a control (Group C) and a new silicone-coated membrane oxygenator, which is of the same construction as that of the one used for Group C, for 5 (Group S). ⋯ As for hemolysis, however, the plasma free hemoglobin of Group S was lower than that of Group C. Currently, 3 chronic percutaneous cardiopulmonary support (PCPS) experimental models have been conducted, and there has been no evidence of thromboembolism or deterioration of the oxygenator. In conclusion, this new oxygenator is suitable not only for CPB, but also for long-term cardiac support.
-
The purpose of this study was to evaluate the change of regional cerebral oxygen saturation (rSO2) during percutaneous cardiopulmonary support (PCPS) in patients with cardiogenic shock. Fifteen patients with cardiogenic shock were evaluated during PCPS by continuous monitoring of rSO2, systemic venous oxygen saturation (Svo2), and hemodynamics. The brain damage of these patients was also evaluated during and after PCPS. ⋯ There was no correlation between brain damage and rSO2. The patients with low rSO2 (< 50%) that resulted in poor LV function could not be weaned from PCPS. In conclusion, the continuous monitoring of rSO2 during PCPS could be a useful tool.