Intravenous (IV) access provides a direct pathway into the bloodstream for delivering fluids and medications quickly. IV patency refers to the state of the catheter being open and functioning correctly, allowing for the smooth, uninterrupted flow of therapy into the vein. Maintaining this patency is important for the safe and effective delivery of treatment, as a compromised line can lead to serious complications. Understanding how to check the line and recognize problems is necessary for ensuring the integrity of the IV system.
Active Assessment Methods for Patency
The most direct way to check patency involves actively testing the line using a sterile saline solution. Healthcare providers use a syringe to flush the catheter, observing for any resistance to the pressure applied. A properly functioning IV line accepts the flush easily without causing discomfort or pain at the insertion site.
A technique known as the “push-pause” method is often used during flushing to help prevent clotting within the catheter. This involves injecting a small volume of saline (typically 1–2 milliliters) with a quick, forceful motion, followed by a brief pause before repeating the action. This turbulent flow helps dislodge any residual blood or medication adhering to the inner walls of the catheter tip.
Another check involves aspirating the line to confirm venous placement by attempting to draw blood back into the syringe. The appearance of blood return is a strong sign that the catheter tip is correctly positioned within the vein. However, for smaller peripheral IVs, a blood return may not always be visible, even if the line is functioning correctly.
When fluids are infusing, observing the flow rate provides a continuous, passive check on patency. If the IV is running by gravity, the drip rate should be consistent and steady. For lines connected to an infusion pump, the absence of frequent “occlusion” or “downstream blockage” alarms indicates the system is working as intended.
Recognizing Signs of Compromised Patency
A patent IV can quickly become compromised, often signaling a complication like infiltration or phlebitis. Infiltration occurs when the catheter dislodges or punctures the vein wall, allowing the infused fluid to leak into the surrounding subcutaneous tissue. The observable signs include swelling or puffiness around the IV site, a feeling of tightness, and the skin becoming noticeably cool to the touch and appearing pale or blanched.
Phlebitis, which is inflammation of the vein wall, presents with symptoms that indicate irritation or damage to the vessel itself. Patients may report pain or tenderness along the path of the vein, which will appear red and feel warm to the touch. In some cases, the inflamed vein may feel like a firm, cord-like structure when lightly palpated.
A common issue is an occlusion or blockage, often caused by a blood clot (thrombus) forming at the catheter tip. This complication is indicated by an inability to flush the line smoothly, meeting noticeable resistance when attempting to inject saline. If the line is connected to a pump, an occlusion will often trigger an alarm signaling high pressure in the line.
Immediate Actions When Patency Fails
If any sign of compromised patency is observed, the immediate action is to stop the infusion or clamp the IV line to prevent further fluid delivery. This is a necessary safety measure, whether the issue is a simple occlusion or a complication like infiltration. Continuing to infuse fluid into compromised tissue can worsen swelling or cause significant tissue damage, especially if the fluid is an irritating medication.
Once the infusion is stopped, the healthcare provider must decide whether to remove the catheter. If infiltration or phlebitis is confirmed, the catheter is typically removed immediately to prevent further injury to the vein or tissue. After removal, the affected extremity is often elevated to help reduce swelling.
The site management that follows depends on the type of complication and the solution that was infusing. For infiltration of a non-irritating solution, a cold compress may sometimes be applied to the area, but warm compresses are more commonly used for phlebitis to help alleviate inflammation and improve circulation. The event and all subsequent actions, including patient assessment and site care, must be carefully documented, and the physician or ordering provider should be notified of the IV failure.