Tubes, Catheters, Lines and Collection Devices -- Continued

Nasogastric and Nasoenteric Tubes

NG Tubes – Passed from nose to stomach.

NE Tubes – Passed from nose to duodenum.

Uses:

1. Feeding the patient

2. Decompression (aspirate gas and fluid from the stomach)

3. Radiographic examination of the stomach

 

Central Venous Pressure Line (CVP) - Catheter that is inserted into a large vein.

Types:

1. Central venous catheters

2. Venous access devices

Wide variety of clinical applications:

1. Mainly used for chemotherapy and parenteral nutrition

2. Administer a variety of drugs

3. Manage fluid volume

4. Serve as a conduit for blood analysis and transfusions

5. Monitor cardiac pressures

 

First developed by Broviac, then later by Hickman, hence the names of the CVP lines.

CVP Lines:

1. Port-A-Cath (chemotherapy)

2. PICC (peripherally inserted central catheter)

3. Swan-Ganz catheter

They may be single-, double- or multi-lumen. Most common insertion site is subclavian vein; also can be internal jugular and femoral veins. Position should be superior vena cava, approximately 2 to 3 cm above the opening of the right atrium.

 

PICC Line Placement - Placed to help monitor and manage critical patients and patients requiring long-term care.

Placed in the pulmonary artery, central vein (CVC) or peripherally (PICC). Care must used to avoid disruption of catheter. Often requires the use of the C-arm during insertion. Mobile images are often used to verify placement.

 

Pulmonary Arterial (PA) Catheter - Swan-Ganz catheters

Incorporates a small electrode at distal end, used to monitor pulmonary arterial pressure. Access to left ventricle requires arterial approach. Catheter placement in the left ventricle has major physiologic consequences. Safest way to assess left-sided heart pressure is to extrapolate its value by monitoring right-sided heart and pulmonary pressures. Distal tip will be in one of the two pulmonary arteries. Has balloon on distal end; during pressure monitoring inflates balloon and allows tip to float and wedge in pulmonary artery. It measures pressure and then the balloon deflates.

 

Technologist Responsibilities

Radiographic confirmation of line placement is essential at the time of insertion and thereafter as needed.

Recognition of catheter malposition requires thorough knowledge of CV structures and their branches.

Without any expectation of the radiographer to interpret the image from a pathologic diagnostic standpoint, when malpositioning is thought to occur, alerting the appropriate authority (e.g., radiologist, attending physician) is both appropriate and beneficial to the patient.

 

Intravenous and Intraarterial Lines

Sterile technique is required for the insertion of lines (catheters) into veins and arteries. They are used for a variety of purposes. They are classified as venous and arterial lines. Requires imaging to confirm placement and functionality. Technologists must be ever-aware of lines and their equipment and positioning.

 

Pacemakers - Permanent pacemakers are electromechanical devices inserted under the patient's skin that regulates the heart rate by providing low levels of electrical stimulation to the heart muscle.

Pacemaker units are approximately 1 inch in width, in diameter and in thickness, weighing just a little over 1 ounce. The role of the radiographer is to operate the fluoroscopy unit, which will allow the physician to place the guidewire and pacemaker assembly correctly. Newer pacemaker designs are MRI compatible.