Thrombotic Complications After Central Venous Catheterization

Rationale: Complications related to central venous catheterization are mechanical, infectious or thrombotic in origin. Potential complications of catheter-related thrombosis are not insubstantial and include pulmonary embolism, post-thrombotic syndrome or thrombophlebitis. Prevalence and incidence of catheter-related thrombosis at the intensive care unit is unclear and treatment, especially of asymptomatic thrombosis, remains ambiguous. Therefore a study is warranted that evaluates the prevalence and incidence of catheter-related thrombosis and investigates its potential consequences. We hypothesize that the incidence of catheter-related thrombosis is 5-15%.

Objective: To assess the prevalence and incidence of symptomatic and asymptomatic catheter-related thrombosis.

INTRODUCTION AND RATIONALE

Since its introduction, central venous catheter (CVC) use has been increasing and is now indispensable in modern-day medical practice. Besides its imperative use in critically ill patients, there are multiple complications associated with central venous catheterization. Complications are mechanical, infectious or thrombotic in origin. There is a growing body of literature that recognises the potential deleterious consequences of catheter-related bloodstream infections and this complication has been the main focus of research. In contrast, despite catheter-related thrombosis being a well-known complication and accounting for approximately 15 percent of all venous thromboses in ICU patients, its exact incidence and potential consequences in ICU patients remain unclear.

Histologically, due to intravascular movement of the CVC focal areas of endothelial injury in the vein wall adjacent to the catheter occur. Simultaneously, a fibrin sheath grows along the catheter surface from the venotomy site. The fibrin sheath, in combination with endothelial injury and a decreased blood flow around the catheter triggers the development of catheter-related thrombosis. The formed thrombus can gradually increase in size until there is occlusion of the vein and, subsequently, symptoms of localized swelling, pain, tenderness and erythema along the course of the vein may occur.

Up to now CVCs are removed without routinely investigating the presence of catheter-related thrombosis. Therefore, its exact incidence is ambiguous and among asymptomatic patients the natural course of catheter-related thrombosis remains uncertain. Potential consequences of catheter-related thrombosis are not insubstantial; they include pulmonary embolism, post-thrombotic syndrome, thrombophlebitis, treatment delay, and loss of venous access. However, a study by Jones et al., conducted in children who received a CVC in the internal jugular or femoral vein, showed low risk for developing short and long-term sequalae after catheter-related thrombosis. Moreover, another study by White et al. showed no increased risk of developing pulmonary embolism after central venous catheter placement.

To date, there is no consensus regarding treatment of catheter-related thrombosis in ICU patients. In case it becomes symptomatic, guidelines for lower extremity deep vein thrombosis are followed and patients are treated accordingly. However, in case catheter-related thrombosis is an accidental find and remains asymptomatic, treatment is more controversial. Some physicians decide to treat it with anticoagulants, whereas others do not treat it at all.

If we take into account that the natural history of catheter-related thrombosis remains unclear in adult ICU patients and its treatment is even more controversial, a study is warranted that investigates the incidence and potential sequelae of catheter-related thrombosis. The primary aim of this study is to evaluate the incidence of catheter-related thrombosis in adult ICU patients and to investigate its relationship with potentially hazardous sequelae.

OBJECTIVES

Primary Objective:

- To evaluate the prevalence and incidence of catheter-related thrombosis in adult ICU patients

Secondary Objectives:

* To investigate the correlation between catheter-related thrombosis and catheter-related infections
* To identify potential risk factors associated with catheter-related thrombosis
* To investigate the association of catheter-related thrombosis with potential sequalae

Eligibility Criteria:
Inclusion Criteria:

* Central venous cannulation of the internal jugular vein, subclavian vein, or femoral vein
* ≥ 48 hours catheter indwelling time

Exclusion Criteria:

* Removal of the CVC within 48 hours after placement
* Pre-existent thrombosis at vein of insertion site
* Discharge of patients from ICU with CVC in situ
* Inability to perform compression and colour Doppler ultrasound evaluation of cannulated vein