is able to effect gas exchange with venous blood draining from all of the tissues of the body thereby providing an excellent opportunity for exchanging the entire basal oxygen consumption and carbon dioxide production of the body at each of the gas exchange regions 40 42 44 there is a plurality of manifold sleeves 54 sealingly fixed to the catheter 22 at side by side spaced apart locations as seen particularly well in fig6 each of the manifold sleeves 54 overlies and contains a pair of apertures 56 58 in the catheter 22 the apertures 56 are sized and positioned to communicate with the inlet conduit 24 while the apertures 58 are sized and positioned to communicate with the outlet conduit 26 each manifold sleeve 54 is coaxial with the catheter 22 having a cylindrical wall 60 with an outer peripheral surface which is parallel to that of the outer surface of the catheter 22 in this manner an annular space 62 is defined between the outer peripheral surface of the catheter and the cylindrical wall 60 additionally the cylindrical wall 60 is formed with a plurality of ports 64 see fig6 and 8 which extend therethrough at a large number of longitudinally and circumferentially spaced locations a pair of perforated end caps 66 68 positioned in spaced parallel planes are sealingly attached to the catheter 22 and to the cylindrical wall 60 epoxy or other suitable adhesive may be employed for this purpose the components of the manifold sleeves 54 are preferably composed of polycarbonate because of its.