ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
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To evaluate continuous venovenous hemofiltration and hemodiafiltration with a conventional infusion pump in a pediatric sized animal model. Fourteen Maryland pigs weighing 8 to 13 kg were used. A conventional infusion pump (IVAC 571), with a flow of 900 ml/h and a pediatric hemofilter of 0.22 m2 were used. ⋯ Pressure in the circuit rose from 107.7 +/- 70.3 mm Hg at the beginning of the experiment to 234.2 +/- 118.1 mm Hg after 2 hours (p < 0.05). The technique was well tolerated by all the pigs. Continuous venovenous hemofiltration and hemodiafiltration with a conventional infusion pump is a possible alternative to conventional methods of extrarenal replacement therapy in neonates and infants.
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The controller presents a major obstacle in the development of the rotary blood pump as a left ventricular assist device (LVAD). Clinically, LVAD flow is a good indicator in the regulation of circulatory conditions and pump flow changes, depending on pump preload and afterload. Many investigators have tried estimating pump flow by referencing the motor current. ⋯ In pulsatile conditions, however, the H-Q curve is a loop that changes under various LV contractility conditions, complicating determination of linear equation for calculating flow. In addition, the LV chamber in the test loop cannot mimic native heart contractility as described by Starling's law. This finding can lead to a misanalysis of the H-Q curve under pulsatile conditions.
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The HemoCue B-hemoglobin test system (HemoCue, Inc., Mission Viejo, CA) is a photometric method for rapid bedside determination of hemoglobin (Hb). We compared the performance of HemoCue measured Hb against Coulter STK-S (CSTK) measured Hb in chronic hemodialysis (HD) patients in two different settings. In the first setting, Hemocue analysis was performed by multiple HD technicians (n = 132). ⋯ After reviewing the two protocols, the primary difference in the two studies was the technique used to obtain the specimens. When performed properly, Hb testing using the HemoCue testing system had a high level of agreement with CSTK. Appropriate training in specimen handling, as well as test performance, will increase accuracy and reliability of bedside hemoglobinometry.
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To evaluate the ability of arteriovenous carbon dioxide removal (AVCO2R) to maintain hemodynamic stability during treatment of adult respiratory distress syndrome (ARDS), we used our smoke/burn, LD40 sheep model of ARDS. With onset of ARDS (PaO2/FiO2 < 200) animals were randomized to AVCO2R (n = 20) or SHAM (n = 8). ⋯ At 48 hours, AVCO2R allowed significant reductions (p<0.05) in minute ventilation (13.6+/-2.5 to 7.6+/-0.8 L/min); tidal volume (TV) (389.4+/-24.1 to 295.0+/-10.1 ml); peak inspiratory pressure (PIP) (25.4+/-9.2 to 18.8+/-2.5 cm H2O); RR (27.5+/-0.7 to 21.6+/-1.8 breaths/min); and FiO2 (0.96+/-0.00 to 0.48+/-0.2) while normocapnia was maintained. AVCO2R is an effective method of CO2 removal during severe respiratory failure that is hemodynamically well tolerated.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of three commercially available hollow fiber oxygenators: gas transfer performance and biocompatibility.
The new generation of oxygenators have improved blood flow pathways that enable reduction in priming volume and, thus, hemodilution during cardiopulmonary bypass (CPB). We evaluated three oxygenators and two sizes of venous reservoirs in relation to priming volume, gas transfer, and blood activation. To compare priming volume, gas transfer, and biocompatibility of three hollow fiber oxygenators and two different size venous reservoirs, 60 patients were randomly allocated in groups to undergo cardiopulmonary bypass. ⋯ The oxygenator with the largest blood contact surface area and improved geometric configuration (group 3) showed the lowest oxygen transfer rate per square meter. However, this oxygenator elevated oxygen partial pressure the most and reduced carbon dioxide partial pressure the most. In group 2, where a smaller venous reservoir was used, the highest blood activation was observed.