An apparatus includes a catheter, an introducer, and an actuator. A distal end portion of the introducer has a lock configured to couple the introducer to a closed system intravenous line at least partially disposed in a body. The lock is configured to transition a seal of the closed system intravenous line from a closed state to an open state when coupled thereto. The actuator is at least partially disposed in the introducer and coupled to a proximal end portion of the catheter. The actuator is configured to move the catheter between a first position, in which the catheter is disposed within the introducer, and a second position, in which the catheter extends through the seal of the closed system intravenous line such that a distal end surface of the catheter is positioned distal to the closed system intravenous line.