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Biomedical subjects

K L Drake

Publications and source records attributed to K L Drake.

4 recordsLinked to original sources
PubMed1987

Venovenous extracorporeal membrane oxygenation (ECMO) using a double-lumen cannula.

Extracorporeal membrane oxygenation (ECMO) can support neonates with severe respiratory failure. Currently, the most common application of ECMO requires venoarterial access. Venovenous (VV) ECMO is desirable to avoid common carotid artery ligation. However, the best technique of venous access for VV ECMO is not established. Using a single cannula with a double-lumen (DLC) in the right atrium for simultaneous drainage and infusion of blood, VV ECMO provided total respiratory support for six apneic puppies for 3 h each. Mean systemic arterial oxygenation was lower with DLC VV (50 torr) compared to VA ECMO (247 torr), but a physiologic pH (mean 7.34) was maintained on DLC VV bypass. Higher mean bypass flow was required on DLC VV (124 ml/kg/min) compared to VA flow (101 ml/kg/min) because of recirculation of oxygenated blood. The position of the DLC in the right atrium needed to be closely monitored. Hemorrhage was noted in the myocardium after use of DLC VV ECMO.

Animals↗
PubMed1981

The effect of hemofiltration on fiber platelet concentration.

Experimental methods and apparatus were developed to measure platelet concentration in an ultrafiltering hollow fiber with blood and ultrafiltrative flow rates that are characteristic of current hemofiltration practice. Values are presented for the adjusted local platelet concentration, which allows for the expected increase due to loss of ultrafiltrate volume. Platelet concentrations in fiber samples are of interest since ultra-filtration can create platelet polarization in a fashion similar to the concentration polarization that occurs for proteins. For many combinations of inlet flow rate, ultrafiltrative flow rate, and fiber dimension, there are significant elevations in adjusted fiber platelet concentration. The adjusted platelet concentrations of the outflow samples are nominally equal to those of the feed (reservoir) samples; thus, reaction and adhesion of platelets is not a significant source of fiber concentration. Experiments with fibers of different diameters indicate that, as expected in concentration polarization, the excess platelets are located near the wall. Data for the fiber platelet concentration depend in a complex fashion upon the inlet wall shear rate and ultrafiltrative velocity. For certain fixed ultrafiltrative velocities, a maximum fiber platelet concentration occurs at an intermediate inlet wall shear rate. The data are qualitatively explained by an extension of a published model involving diffusive, ultrafiltrative, and wall-induced fluxes of red cells and platelets.

Artificial Organs↗