Conceptual and design features of a practical, clinically effective intravenous mechanical blood oxygen/carbon dioxide exchange device (IVOX).

Conceptual and design features of a new intravascular blood gas exchange device include: placing multiple, thin-walled microporous hollow fibers in an elongated arrangement with a small overall outside diameter; covering the outer surface of each microporous hollow fiber with an ultra-thin continuous silicone coating; forming the hollow fibers into a configuration that produces disturbed flow of blood over the external surface of each fiber; placing the device in the subject's vena cava through a femoral or jugular venotomy; producing a flow of oxygen through the lumens of the hollow fibers, permitting exchange of oxygen and carbon dioxide between the venous blood outside and the gas inside the hollow fibers. Based on these principles, a practical, easily insertible, disposable, intravenacaval blood gas exchange device (IVOX) has been fabricated. Currently, devices with from 2,000 to 6,000 square centimeters of gas transfer surface area are being placed in the vena cavae of dogs and sheep for up to 7 days without altering the animal's hemodynamics, without producing serious hematologic sequelae, and with the capability of transferring in excess of 100 ml of oxygen and carbon dioxide to and from the venous blood of an intact, awake, standing animal. Clinical trials on human subjects with severe, acute, potentially reversible respiratory failure are in the planning stage.