Catheter assembly

A method for inserting a catheter into a blood vessel of a patient, the method comprising:

• providing a catheter assembly comprising:
• the catheter, which has a first lumen,
• a catheter hub joined to a proximal end of the catheter,
• a reinforcement needle inserted through the first lumen of the catheter, having a second lumen, and including a distal portion that is blunt,
• a reinforcement needle hub joined to a proximal end of the reinforcement needle,
• an inner needle inserted through the second lumen of the reinforcement needle and including a sharp needle tip at a distal end thereof,
• an inner needle hub joined to a proximal end of the inner needle,
• a first fixing portion configured to fix the catheter hub and the reinforcement needle hub so as not to be detachable by an operation of pulling the catheter hub and the reinforcement needle hub in an axial direction, and
• a second fixing portion configured to fix the reinforcement needle hub and the inner needle hub to each other, wherein:
• a rigidity of the reinforcement needle is higher than a rigidity of the catheter, and the reinforcement needle protrudes from a distal end of the catheter, and
• the inner needle protrudes from a distal end of the reinforcement needle;
• holding the catheter hub 20 and the reinforcement needle hub of the catheter assembly;
• puncturing the blood vessel of the patient with the needle tip of the inner needle such that blood inside the blood vessel flows back through the inner needle and flows into the inner needle hub;
• gripping the inner needle hub and pulling the inner needle hub toward a direction of a proximal end of the catheter assembly, while the reinforcement needle and the reinforcement needle hub are not pulled out from the catheter assembly;
• after the inner needle and the inner needle hub are completely removed from the catheter assembly, pushing forward the catheter into the blood vessel in a state of being reinforced by the reinforcement needle;
• and
• after the distal end of the catheter is inserted into the blood vessel by a desired length, releasing a locked state between the catheter hub and the reinforcement needle hub, pulling out the reinforcement needle hub from the catheter hub 20 so as to completely remove the reinforcement needle and the reinforcement needle hub from the catheter and the catheter hub.