Study objectives: To determine the frequency of and potential risk factors for catheter-related deep venous thrombosis (DVT) in critically ill adult patients.
Design: Prospective, controlled, observational cohort study.
Setting: A mixed medical and surgical ICU in a university hospital.
Patients: All adult patients undergoing femoral vein catheterization.
Measurements: ICU diagnosis, underlying disease, demographic data, type of catheter, complications during cannulation, use of anticoagulants, coagulation status, medications infused, and duration of catheterization were recorded. Compression and duplex Doppler ultrasound studies of both femoral veins were performed prior to insertion, at 12 h after insertion, and daily until catheter removal. Follow-up investigation was performed at 24 h and 1 week after removal.
Results: Of 140 cases entered into the study, 124 were evaluated. Fourteen patients developed iliofemoral vein DVTs. Two were clinically obvious. Twelve (9.6%) were line related (uncannulated leg normal) and two (1.6%) occurred only in the uncannulated leg (p = 0.011; relative risk, 6.0; confidence interval, 1.5 to 23.5). Line-related DVT can occur any time from the day after insertion to 1 week after removal. The incidence of catheter-related DVT was unrelated to number of insertion attempts, arterial puncture or hematoma, duration of catheterization, coagulation status, or type of infused medications. No other predisposing or protective factors were identified. Three of the 12 patients with catheter-related DVT died. In no patient was clinical pulmonary embolus suspected.
Conclusion: Although the femoral route is convenient and has potential advantages, the use of femoral lines increases the risk of iliofemoral DVT. Catheter-related DVT may occur as soon as 1 day after cannulation and is usually asymptomatic. This increased risk should be carefully considered when the femoral route of cannulation is chosen.