Establishing and Maintaining Vascular Access
Summary of Key Points
• Three questions to ask when selecting a catheter system are: (1) Which device best meets the patient’s therapy and lifestyle needs? (2) How is the device most safely inserted and maintained? (3) What are the potential immediate and long-term complication risks?
• Types of central access systems are the traditional central line for short-term use, tunneled central lines for long-term use, surgically implanted infusion ports, and peripherally inserted central catheters.
• Vascular access devices can be placed using a number of anatomic sites to access the superior vena cava or inferior vena cava: the subclavian vein, internal jugular vein, external jugular vein, and femoral vein.
• Insertion can be performed via the Seldinger (closed) technique or by operative exposure of the vein (open technique).
• Short-term complications include vascular laceration, arterial puncture, pneumothorax (2%), hemothorax, and air embolus (overall placement complications should be <5%).
• Long-term complications include catheter exit site or tract infection, catheter-associated sepsis, cardiac arrhythmias, catheter colonization, catheter thrombus (~30%), fibrin sheath, extravasation, occluded catheter, and shearing of the catheter.
• Factors increasing the risk of catheter-associated infection include prolonged duration of indwelling time, multiple-lumen catheters, femoral locations, non–catheter-related bacteremia (in a neutropenic patient), the number of times the system is accessed, difficult catheter placement, and poor technique in catheter or port-site care.
1. Which of the following scenarios requires complete removal of the central venous catheter?
A Excellent gravity flow when lying down, absent gravity flow when standing, kinking of the catheter at the level of the clavicle on chest radiograph
B Positional gravity flow, slow blood return, catheter location into the contralateral subclavian vein on chest radiograph
C Cardiac arrhythmia with the catheter tip located in the right atrium seen on chest radiograph
D Excellent gravity flow in all positions, no blood return, catheter tip positioned in the superior vena cava just above the level of the right atrium
2. “Catheter colonization or infection” is defined as:
A The positive culture of a segment of removed catheter
B A positive culture at the catheter insertion site
C A positive blood culture from a site other than the catheter and the positive culture of a segment of removed catheter with the same pathogen
D Fevers or other signs of infection in a patient with a central venous catheter in place
3. Initial treatment of a clotted central venous catheter commonly includes:
1. Answer: A. “Pinch-off syndrome” occurs when the central venous catheter is inserted too close to the first rib and clavicle. This syndrome is characterized by excellent gravity flow through the catheter when the patient is lying down and absent gravity flow when the patient is standing. Oftentimes the catheter can be seen as kinking at the level of the clavicle as it passes into the chest. The risk of pinch-off syndrome is catheter breakage. To avoid the potentially devastating complication of a fractured central venous catheter tip in the right atrium, the catheter should be removed in the setting of pinch-off syndrome. Catheter malpositioning into the contralateral subclavian vein may result in suboptimal catheter function; however, this problem can often be fixed with fluoroscopic guidance. Cardiac arrhythmia due to catheter placement into the right atrium can be a life-threatening complication. Generally, the catheter tip can be repositioned by simply withdrawing the catheter back into the superior vena cava with resolution of the arrhythmia. If the catheter tip appears to be well positioned in the superior vena cava just above the level of the right atrium but is not returning blood, a fibrin sheath may be acting as a one-way valve obstructing return. If catheter gravity flow is satisfactory in this setting, the fibrin sheath may be dissolved with the use of tissue plasminogen activator (TPA) and the catheter may be salvaged.
2. Answer: A. The confusing terminology regarding line-related infections can make the literature on this topic difficult to interpret. Local infection is a positive culture at the catheter insertion site. Catheter colonization or infection is the positive culture of a segment of removed catheter. Catheter-associated bacteremia is evidenced by a positive blood culture from a site other than the catheter and the positive culture of a segment of removed catheter with the same pathogen.
3. Answer: A. Catheter malfunction caused by a fibrin sheath usually demonstrates good gravity flow and no blood return because the sheath acts as a one-way valve, allowing inflow but not outflow through the catheter. When intraluminal fibrin and platelets occlude the catheter, the catheter will demonstrate neither gravity flow nor return, regardless of any positional changes. If the caregiver is convinced that the catheter malfunction fits one of these categories and appropriate catheter position is confirmed on a chest radiograph, catheter thrombolysis is indicated. TPA is a serine protease that can dissolve occluding blood clots for up to 80% of patients. Contrast venography is not necessary before using TPA to open nonmechanical catheter occlusions. If thrombolysis successfully disrupts the obstructing occlusion, it is not necessary to change or remove the central catheter.
