A microfluidic device for continuous, real time blood plasma separation is introduced. The principle of the blood plasma separation from blood cells is supported by the Zweifach-Fung effect and was experimentally demonstrated using simple microchannels. The blood plasma separation device is composed of a blood inlet, a bifurcating region which leads to a purified plasma outlet, and a concentrated blood cell outlet. It was designed to separate blood plasma from an initial blood sample of up to 45% inlet hematocrit (volume percentage of cells). The microfluidic network was designed using an analogous electrical circuit, as well as analytical and numerical studies. The functionality of this device was demonstrated using defibrinated sheep blood. During 30 minutes of continuous blood infusion through the device, all the erythrocytes (red blood cells) traveled through the device toward the concentrated blood outlet while only the plasma was separated at the bifurcating regions and flowed towards the plasma outlet. The device has been operated continuously without any clogging or hemolysis of cells. The experimentally determined plasma selectivity with respect to blood hematocrit level was almost 100% regardless of the inlet hematocrit. The total plasma separation volume percent varied from 15% to 25% with increasing inlet hematocrit. Due to the device's simple structure and control mechanism, this microdevice is expected to be used for highly efficient continuous, real time cell-free blood plasma separation from blood samples for use in lab on a chip applications.

Each year thousands of patients require extracorporeal life support (ECLS) for a variety of respiratory, cardiac, and emergency reasons. The ECLS registry, a Federal Drug Administration approved control group, provides a database of approximately 37,000 ECLS patients from domestic and international hospitals, with details about demographic factors, diagnosis, treatment, and complications. The report is circulated to Extracorporeal Life Support Organization members with the goal of providing feedback on each center's practices relative to the performance of all of the centers, and to the general public with the goal of enhancing research and improving patient care. In this report, the ECLS Registry Report International Summary for July 2008 is analyzed with a specific focus on neonatal and pediatric cardiac patients. From the data, it is evident that cardiac ECLS patients have a lower chance of survival than respiratory ECLS patients, and furthermore, younger patients have a lower chance of survival. Requirement for inotropes while on ECLS is by far the most common complication, followed by surgical site bleeding, necessitating hemofiltration. The major mechanical complications facing cardiac ECLS patients are oxygenator failure and clots in the circuit. Databases such as this one provide powerful tools for institutions, clinicians, and researchers.

These results suggest that selection of device type and flow rate can influence vascular pulsatility and input impedance, which might affect clinical outcomes.

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The controversy over the benefits of pulsatile and nonpulsatile flow during cardiopulmonary bypass procedures continues. The objective of this investigation was to review the literature in order to clarify the truths and dispel the myths regarding the mode of perfusion used during open-heart surgery in pediatric and adult patients. The Google and Medline databases were used to search all of the literature on pulsatile vs. nonpulsatile perfusion published between 1952 and 2006. We found 194 articles related to this topic in the literature. Based on our literature search, we determined that pulsatile flow significantly improved blood flow of the vital organs including brain, heart, liver, and pancreas; reduced the systemic inflammatory response syndrome; and decreased the incidence of postoperative deaths in pediatric and adult patients. We also found evidence that pulsatile flow significantly improved vital organ recovery in several types of animal models when compared with nonpulsatile perfusion. Several investigators have also shown that pulsatile flow generates more hemodynamic energy, which maintains better microcirculation compared with nonpulsatile flow. These results clearly suggest that pulsatile flow is superior to nonpulsatile flow during and after open-heart surgery in pediatric and adult patients.