Abstract: A method of making a dual lumen catheter which is a unitary, elongated, flexible catheter tube that is substantially circular in cross-section. The catheter tube has an outer wall member forming a tube having a proximal end and a distal end portion adapted for insertion within a vein or artery of a patient. The outer wall member defines first and second coaxial lumens that are separated by an inner common support wall which is substantially circular and joins the outer wall. The first lumen extends longitudinally between the opposed distal and proximal ends of the catheter tube and terminates coextensive with the distal end portion of the catheter tube. The second lumen extends longitudinally from the proximal end of the catheter tube and terminates proximal to the distal end portion of the catheter tube. The second lumen is crescent-shaped in cross-section and substantially surrounds the first lumen. The cross-sectional areas of the first and second lumens are approximately equal.

Abstract: The invention includes a dual lumen catheter which is a unitary, elongated, flexible catheter tube that is substantially circular in cross-section. The catheter tube has an outer wall member forming a tube having a proximal end and a distal end portion adapted for insertion within a vein or artery of a patient. The outer wall member defines first and second coaxial lumens that are separated by an inner common support wall which is substantially circular and joins the outer wall. The first lumen extends longitudinally between the opposed distal and proximal ends of the catheter tube and terminates coextensive with the distal end portion of the catheter tube. The second lumen extends longitudinally from the proximal end of the catheter tube and terminates proximal to the distal end portion of the catheter tube. The second lumen is crescent-shaped in cross-section and substantially surrounds the first lumen. The cross-sectional areas of the first and second lumens are approximately equal.

Abstract: Disclosed is a dual lumen catheter for insertion within a blood vessel of a patient. The dual lumen catheter has an elongated flexible tube with three conduits contained therein. The first and second conduits are connected together by an opening in the common wall therebetween, which opening extends through the wall of the catheter tube. The third passageway forms a second lumen. Each of the lumens has means adapted for placement of the lumen in fluid communication with a source of liquid to be administered to the patient through the catheter, to means for withdrawing a blood sample or to means for monitoring blood pressure.