Central venous catheters

Commonly placed in ICU’s to accurately monitor hemodynamics, easy blood sampling and provide convenient conduit for infusion of intravenous fluids, drugs and nutritional support.

They allow for the administration of vasoactive drugs, irritating or hypertonic solutions, simultaneous infusion of multiple medications, as well as for hemodialysis and hemodynamic monitoring.

Approximately 18% of hospitalized patients undergo CVC placement during admission, and the number is greater on the hematology ward or in the ICU with patients also frequently have thrombocytopenia.

Prophylactic platelet transfusion before CVC placement in patients with platelet counts of 10 to 50,000 per cubic millimeter reduces CVC related bleeding events.

Devices include surgically tunneled, externalized single or multiple lumen catheters and fully implanted catheters connected to diaphragm-like ports positioned under the skin of the chest.

Recommended guidelines to prevent air embolism from catheter removal include: having the patient in the supine or Trendelenburg position, having the patient perform the Valsalva maneuver or hold their breath and the immediate placement of an occlusive dressing.

Associated infections in more than 200,000 patients per year in the U.S.

Associated with thromboembolism.

Bloodstream infection associated with catheters lead to increases in morbidity, death, length of stay and costs.

In the U.S. 15 million days are estimated to occur each year in ICU patients and are associated with 80,000 catheter related bloodstream infections.

Mortality of central venous catheter related bloodstream infections ranges from 0%-11.5% and excess ICU length of stay 9-12 days.

Improvements in measurement of infectious episodes in the ICU has led to a 58% decrease in central line associated bloodstream infections across the United States.

Pharmacological prophylaxis has decreased the risk of CVC-related venous thromboembolism in ICU patients.

Overall CVC related bloodstream infections not linked with excess mortality, but US Centers for Disease Control and Prevention reports central line associated bloodstream infections have a 12-25% mortality rate.

Indications for obtaining blood cultures in the presence of a central venous catheter include fever, hypothermia, chills, leucocytosis, left shift of neutrophils, neutropenia, and the development of unexplained organ dysfunction.

Complications include infections, thrombophlebitis, thromboembolism, hematoma and pneumothorax.

Infections are usually related to extraluminal colonization from the skin.

More than 50% of related infections are preventable.

Most common organisms associated with infections are coagulase negative staphylococci, aerobic gram-negative bacilli and Candida albicans.

Recommended to prevent bloodstream infections to utilize roper hand hygiene, use maximal barrier protection, use chlorhexidine gluconate (Hibiclens) for catheter insertion, and avoidance of routine catheter changes.

When risk for infection is high or when the catheter will be utilized for a prolonged period of time antibiotic impregnated catheters are recommended.

A foreign body that can activate coagulation locally and interact physiologically with hereditary and acquired hypercoaguable processes to cause thrombosis.

Approximately 9% of initial thromboembolic events are causally related to a central venous catheter or a transvenous pacemaker.

Most important cause of thrombosis of the arm.

Over 10% of patients will develop a symptomatic venous thrombosis of the upper extremity.

A recently placed device increases the risk of an upper extremity deep vein thrombosis by 5-7 fold.

Greatly increase the risk of DVT in the upper extremities in patients with cancer.

Thrombosis associated with attempting venous access with more than one insertion, a patients placement of a previous catheter and ovarian cancer.

Catheter blockage frequently associated with thrombosis.

Long term complications of postphlebitic syndrome and pulmonary embolus are infrequent.

A meta-analysis Of 8 randomized controlled trials of thrombo-prophylaxis in patients with cancer and CVCs concluded no significant effect on the risk of catheter-related thrombosis (Chaukiyal P).

In the warfarin thromboprophylaxis in cancer patients with CVCs (WARP) study, an open label randomized trial warfarin at 1 mg per day or warfarin dose adjusted for an INR of 1.5-2.0 neither arm had any effect in reducing the incidence of catheter-related thromboses (Young AM).

The epidemiology of CVCs has shown that there is shift from use in ICUs to non-ICU settings.

Presently, CVCs are being used in the majority of cases, 70%, in non ICU patients.

CVCs in non-ICU patients remain in place longer than those inserted in in ICUs, increasing the risk of central line associated blood stream infections and venous thromboembolism.

The presence of a CVC was among the four strongest risk factors associated with venous thromboembolism in hospitalized patients (Woller SC et al).

PICCs (preferably inserted central catheters) are venous catheters inserted peripherally and terminate in central veins such that they may be categorized as CVCs.

Based on the above studies there is little to suggest the use of prophylactic anticoagulation in patients with a central venous catheter.

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