Blood collection devices, systems, and methods

An access system comprising:

• a connector configured to couple with a catheter assembly that comprises a catheter tube configured to be positioned in a blood vessel of a patient;
• a reinforcement member fixedly secured to the connector;
• and
• a cannula movable relative to the reinforcement member from a retracted position in which at least a portion of the cannula is within the reinforcement member to an advanced position, the cannula comprising:
• a polymeric tube that defines a distal tip;
• and
• a support tube that encompasses a portion of and is stiffer than the polymeric tube, the support tube defining an inner diameter that is marginally larger than an outer diameter of the polymeric tube so as to prevent kinking of the polymeric tube, the support tube being in a fixed relationship with the polymeric tube so as to move in unison therewith, the support tube defining a distal edge that is proximally spaced from the distal tip of the polymeric tube and that is configured to be within the reinforcement member when the distal tip of the polymeric tube is first positioned distal of and external to the reinforcement member as the cannula is transitioned from the retracted position to the advanced position,
• wherein, when the connector and the catheter assembly are in a coupled state, at least a portion of the polymeric tube that extends distally beyond the distal edge of the support tube is configured to be advanced through at least a portion of the catheter tube as the cannula is transitioned from the retracted position to the advanced position.