ASAIO journal : a peer-reviewed journal of the American Society for Artificial Internal Organs
-
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.
-
We performed this study to identify predictors of mortality in critically ill patients treated with continuous venovenous hemodiafiltration (CVVHDF) for acute renal failure in an intensive care setting. It was an uncontrolled, observational study that took place in a general intensive care unit in a university hospital. Forty-one patients undergoing CVVHDF for acute renal failure in a consecutive sample of 1,018 ICU treatments were studied. ⋯ The crucial factors in predicting outcome of critically ill patients undergoing CVVHDF for renal failure are elevated serum bilirubin and lactate levels at the onset of CVVHDF. Presence of hepatic failure, defined as both jaundice and coagulopathy, may also worsen outcome of critically ill patients undergoing CVVHDF for renal failure. The cut-off value set at bilirubin levels > 10 mg/dl or arterial lactate levels > 3.5 mmol/L may serve as beneficial predictors of hospital mortality.
-
Nitric oxide (NO) is an inhibitor of platelet aggregation. We analyzed the effect of direct infusion of NO into adult blood oxygenators on local clot formation. Nonheparinized calves in a control group (n = 3) and NO group (n = 4) were connected to a jugulocarotid cardiopulmonary bypass (CPB; centrifugal pump) for 6 hours. ⋯ However, general coagulation parameters were not modified by local NO administration. The activated coagulation time remained stable between 110 and 150 seconds in both groups (p = not significant [ns]), and there were no differences in hematocrit, thrombin time, partial thromboplastin time, or fibrinogen between groups during the 6 hours of CPB. Thus, the mixed infusion of a continuous low dose of NO into adult oxygenators during prolonged CPB prevented local clot formation, whereas the general coagulation pattern remained unchanged.
-
The study objective was to determine whether a phosphodiesterase III inhibitor, olprinone chlorate, is effectively removed by continuous venovenous hemodiafiltration (CVVHDF) in a patient with cardiac and renal failure. The patient was a 73 year old man who had undergone coronary artery bypass grafting for ischemic heart disease and who developed cardiac and renal failure postoperatively. A 0.2 microg/kg per minute dosage of olprinone chlorate was administered intravenously for 120 minutes while the patient was treated with CVVHDF. ⋯ The olprinone chlorate clearance of CVVHDF approximates only 10% of total clearance in this case. CVVHDF may not produce significant reduction in the serum olprinone chlorate level. It is recommended that the infusion dosage of olprinone chlorate should be reduced when given to patients with renal failure even if treated with CVVHDF.
-
Intravenous oxygenation represents a potential respiratory support modality for patients with acute respiratory failure or with acute exacerbations of chronic respiratory conditions. Our group has been developing an intravenous oxygenator, the IMO, which uses a constrained fiber bundle and a rapidly pulsating balloon within the fiber bundle. Balloon pulsation drives blood flow past the fibers at greater relative velocities than would otherwise exist within the host vessel, and gas exchange rates are enhanced. ⋯ Balloon pulsation eliminated much if not all of the dependence of the gas exchange rate on blood flow rate as seen in passive oxygenators. This suggests that in clinical application the IMO may exhibit less gas transfer variability due to differences in cardiac output Over the entire flow rate range studied, the CO2 and O2 gas exchange rates of the IMO at maximal balloon pulsation varied from approximately 250 to 350 ml/min/m2. At maximum balloon pulsation the IMO exchanged CO2 and O2 at rates from 50-500% greater, depending upon the blood flow rate, than the exchange rates reported for the IVOX device in ex vivo tests.