An apparatus includes a catheter, an introducer, and an actuator. A distal end portion of the introducer is configured to couple to an indwelling peripheral intravenous line. The actuator is movably coupled to the introducer and 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 a distal end portion of the catheter is distal to the introducer. A first portion of the actuator is disposed outside of the introducer and in contact with an outer surface of the introducer such that (1) a longitudinal axis defined by a second portion of the actuator is nonparallel to a longitudinal axis defined by the introducer and (2) the second portion of the actuator exerts a force on a proximal end portion of the catheter operable to increase an internal stress with in a portion of the catheter.