I V infiltration: Not just a peripheral problem

Nursing, Sep 1999 by Hadaway, Lynn C

Different I.V. solutions produce differing pain intensity. In one study, infiltrated hypertonic solutions such as 3% sodium chloride were most painful, followed by hypotonic 0.45% sodium chloride. In a test performed with an isotonic solution, pain began immediately after infiltration started, then subsided quickly even if infiltration continued.

In addition, the administration method influences the amount of fluid that escapes into tissue. Compared with a pump-controlled infusion, a gravity infusion creates a smaller amount of pressure on the catheter and vein wall. If infiltration occurs, the infusion will generally slow down. In an elderly patient, however, loose skin may allow the infiltration to progress with little effect on the flow rate.

If a pump-controlled infusion infiltrates, the pump will continue to pump solution into the tissue. This is more likely to produce a large infiltration in a short time.

Fluid manually injected by a syringe can also cause great pressure in tissues and veins-maybe even more than fluid infused by a pump. But because you're present to immediately identify the problems and intervene, less damage may occur.

To complicate assessment, problems associated with infiltration may not always appear at the insertion site. Think not only about where the catheter enters the body, but also about where the medication enters the vein. Assess the entire catheter and adjacent structures, including, for example, the vein entry site, the catheter tip location, and the venous pathway in between those two points. With central lines check the subcutaneous tunnel or port pocket and the neck, jaw, upper extremity, and chest wall ipsilateral to the catheter. Engorged chest wall veins and difficulty in moving the neck or jaw indicate an obstruction to venous blood return and possible thrombosis. By obstructing blood flow, thrombosis causes back pressure in the vein, which may lead to an overflow of fluid from the puncture site.

Unexplained areas of swelling around the venotomy end of a tunneled catheter or an implanted port may indicate catheter fracture with subsequent fluid leakage into the surrounding tissue.

Launching an investigation

If you suspect infiltration, take these steps to investigate:

If the patient has a peripheral catheter, carefully assess both extremities and compare them, looking for differences.

Ask him to describe any discomfort or tightness and when he first noticed it.

Review his medical history. Conditions other than infiltration, such as heart failure, renal failure, or the presence of an arteriovenous fistula, can also cause edema.

Assess for other factors, such as positioning, that could impair blood flow or cause edema and swelling. For example, was he lying on his arm, constricting it mechanically? Could tight clothing or restraints be a factor? Does repositioning change the resistance to flushing or lack of blood flow? If so, the catheter tip may have simply been pressed against the vein wall.

Check the I.V line for patency. Do you find resistance to flushing with a syringe or gravity flow? Has the pump started to beep with an occlusion alarm? Can you easily obtain blood flow from the catheter?