A nurse is caring for a patient with a right radial arterial line. Which action should the nurse take?

Choice A rationale To ensure a continuous flow of flush solution through the arterial catheter and prevent blood from backing up into the tubing, the pressure bag must be maintained at 300 mm Hg. This high pressure overcomes the patient's arterial pressure, which normally ranges from 100 to 140 mm Hg systolic. This constant flow of approximately 3 mL per hour maintains patency of the line and prevents clot formation at the catheter tip, ensuring accurate readings. Choice B rationale An arterial line is strictly used for hemodynamic monitoring and arterial blood gas sampling, not for the administration of medications or intravenous fluids. Injecting antibiotics or other drugs into an arterial line can cause severe vasospasm, arterial occlusion, and potential tissue necrosis or gangrene in the distal limb. All intravenous medications must be administered through a venous access device, such as a peripheral IV or a central venous catheter, to ensure systemic distribution. Choice C rationale Bearing down, or the Valsalva maneuver, increases intra-thoracic and intra-abdominal pressure, which temporarily alters venous return and blood pressure readings. This would result in inaccurate hemodynamic data, as the arterial line is meant to measure the patient's physiological baseline or response to therapy. The patient should remain quiet and still in a supine or semi-Fowler's position with the transducer leveled at the phlebostatic axis to obtain the most reliable and consistent blood pressure measurements. Choice D rationale The Trendelenburg position, where the head is lower than the feet, is used to increase venous return or during certain central line insertions, but it is not appropriate for obtaining arterial line readings. Hemodynamic measurements should be taken with the patient in a neutral position. The transducer must be leveled at the phlebostatic axis, which is the fourth intercostal space at the mid-axillary line, to ensure the hydrostatic pressure does not skew the recorded blood pressure.