An apparatus, comprising: a catheter having a proximal end portion and a distal end portion and defining a lumen extending through the proximal end portion and the distal end portion; an introducer having a proximal end portion and a distal end portion, the introducer defining an inner volume having a first portion and a second portion, the inner volume having a tortuous cross-sectional shape relative to a plane perpendicular to an axis of the first portion and an axis of the second portion such that the axis defined by the first portion of the inner volume is parallel to and offset from the axis defined by the second portion of the inner volume, the first portion of the inner volume being adjacent to a slot defined by the introducer, the second portion of the inner volume being offset from the first portion in a transverse direction along the plane and configured to movably receive the catheter, the distal end portion of the introducer configured to be coupled to an indwelling peripheral intravenous line; and an actuator having a first portion extending through the slot and movably disposed in the first portion of the inner volume and a second portion movably disposed in the second portion of the inner volume, the second portion of the actuator being coupled to the catheter, the actuator configured to move relative to the introducer to move the catheter between a first position and a second position, the catheter disposed within the introducer when in the first position, the distal end portion of the catheter disposed beyond the distal end portion of the introducer such that at least a portion of the catheter is disposed within the indwelling peripheral intravenous line when the catheter is in the second position and the introducer is coupled to the indwelling peripheral intravenous line. a catheter having a proximal end portion and a distal end portion and defining a lumen extending through the proximal end portion and the distal end portion; an introducer having a proximal end portion and a distal end portion, the introducer defining an inner volume having a first portion and a second portion, the inner volume having a tortuous cross-sectional shape relative to a plane perpendicular to an axis of the first portion and an axis of the second portion such that the axis defined by the first portion of the inner volume is parallel to and offset from the axis defined by the second portion of the inner volume, the first portion of the inner volume being adjacent to a slot defined by the introducer, the second portion of the inner volume being offset from the first portion in a transverse direction along the plane and configured to movably receive the catheter, the distal end portion of the introducer configured to be coupled to an indwelling peripheral intravenous line; and an actuator having a first portion extending through the slot and movably disposed in the first portion of the inner volume and a second portion movably disposed in the second portion of the inner volume, the second portion of the actuator being coupled to the catheter, the actuator configured to move relative to the introducer to move the catheter between a first position and a second position, the catheter disposed within the introducer when in the first position, the distal end portion of the catheter disposed beyond the distal end portion of the introducer such that at least a portion of the catheter is disposed within the indwelling peripheral intravenous line when the catheter is in the second position and the introducer is coupled to the indwelling peripheral intravenous line.