As more of what was traditionally considered inpatient care has moved to the outpatient arena, the use of peripherally inserted central catheter (PICC) lines has greatly increased. The ability to provide outpatient administration of intravenous antibiotics and other agents has significant cost and independence benefits for patients, but it also carries some risks. Minor complications, such as entry-site infection and phlebitis, can occur. Less frequently, major adverse effects, such as venous thrombosis and pulmonary embolism, have occurred. To determine the prevalence of thrombosis complications, Chemaly and colleagues retrospectively reviewed a large group of patients who received PICC lines.

Over a 34-month period, a total of 2,063 PICC lines were used in a large referral-center hospital where the study took place. A review of upper-extremity ultrasonograms and venograms that were positive for clotting identified thrombotic episodes. Venous thrombosis related to PICC line placement occurred in 51 patients (2.5 percent). Approximately one half of the thromboses involved only superficial upper-extremity veins, while the others extended into deep venous structures (innominate, subclavian, or internal jugular veins). Pulmonary embolism was identified in two of the 51 patients. About one half of the thrombotic episodes occurred within the first two weeks of line placement.

To compare risk factors with the patients who had venous thrombosis, the reviewers randomly selected 107 control patients who did not clot after PICC placement. Factors associated with a significantly higher risk for clotting were intravenous amphotericin B therapy (tenfold increased risk) and younger age. Patients who had not had recent surgery also were at greater risk. The authors postulated that the younger-age risk might have been due to higher rates of HIV infection among the group with thrombotic events, because HIV positivity was of borderline statistical significance as an independent risk factor for clotting. A history of deep venous thrombosis and discharge to a skilled-nursing facility also carried a borderline significance for increased risk.

The authors conclude that, based on their retrospective study results, PICC lines carry a venous thrombosis risk of 2.5 percent (a percentage that may be an underestimation of the true prevalence), and that pulmonary embolism occurred in about one per 1,000 patients. Amphotericin B delivered via the PICC line greatly increased the risk of thrombosis.