ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
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Changes in platelet membrane glycoproteins (GPIb, GPIIb/IIIa, and GMP-140) were evaluated using flow cytometry after binding with monoclonal antibodies in 22 adult patients undergoing cardiopulmonary bypass (CPB) surgery. The amount of GPIb on platelets decreased significantly during CPB, reaching a minimum level of 64 +/- 26% of the pre CPB value at 120 min of CPB. There was no significant change in the amount of GPIIb/IIIa on platelets. ⋯ There was an upper limit to the amount of GMP-140 expression on each platelet in the circulating blood, suggesting that excessively activated platelets are removed from the circulation. The authors conclude that CPB reduces the amount of GPIb on platelets, which results in platelet dysfunction. In addition, removal of excessively activated platelets from the circulation may lead to thrombocytopenia after CPB.
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The placement of peritoneal catheters by non-surgeons was facilitated by a percutaneous laparoscopic technique ("Y-tec"). We have developed a catheter implantation system that is simpler to use, is less expensive initially and per procedure, and provides greatly enhanced peritoneal visualization. The core of the system is a 4 mm diameter Verres needle, which has a protective spring loaded obturator. ⋯ This method uses the safest mode of blind peritoneal entry and permits thorough peritoneal inspection, even without insufflation. The needle and cannula are reusable, which minimizes cost. The technique is simple, and early results with inexperienced operators are encouraging.
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The authors have developed a venovenous extracorporeal lung support technique with an original single lumen cannula to avoid the carotid ligation of venoarterial extracorporeal membrane oxygenation (ECMO). During a 5 year period, the authors have used the technique in 107 neonates (weight: 3.045 +/- 0.6 1 kg; gestational age: 38.1 +/- 2.2 weeks). All of the neonates had severe respiratory failure despite maximal conventional treatment and the same indications as those for ECMO. ⋯ The mean duration of bypass was 117.8 +/- 83.9 hr, and 91 of the 107 (85%) neonates were weaned from AREC. The technical complications were less important than those associated with venoarterial ECMO. The authors conclude that AREC is as effective as venoarterial ECMO and is easier to use.
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The hemodynamic and metabolic adaptations to exercise in five calves implanted with the Utah-100 total artificial heart (TAH) were investigated. The outputs of the left and right ventricles (LCO, RCO) were measured with a cardiac output monitoring and diagnostic unit (COMDU). Arterial and venous oxygen content (CaO2, CvO2) and blood lactate levels (Lac) were measured by blood gas analysis and enzymatic methods. ⋯ During exercise, there was a positive correlation between DO2, EO2, and VO2. The blood pH, BE, SBE, and lactate levels were within normal ranges, and the IMA exceeded 1.5, denoting that tissue perfusion was adequate and anaerobic metabolism did not occur. This study implies that Utah-100 TAH animals could physiologically accommodate to exercise with an intensity of up to 1.8 mph for 30 min by increasing cardiac preload, cardiac output, oxygen delivery, and oxygen extraction rate, and by decreasing systemic and pulmonary vascular resistance without transition to anaerobic metabolism.
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Extracorporeal membrane oxygenation (ECMO) for adult post cardiotomy cardiogenic shock has had limited success. The efficacy of a heparin bonded ECMO system was tested in 11 patients (eight men, three women; mean age: 63 +/- 8 years), all of whom were in post cardiotomy shock refractory to inotropes and intra-aortic balloon pumping (IABP). The system consisted of a right atrial-to-aortic loop using a hollow fiber oxygenator driven by a vortex pump. ⋯ Eight (73%) patients were weaned from ECMO. Five (45.4%) of these are alive and have been discharged home with a mean follow-up of 317 +/- 76 days (range: 179-416 days). This heparin-free ECMO system allows rapid and simple deployment and provides effective short-term cardiopulmonary support.