Anatomy & Vascular Access Evaluation Flashcards

Which vein is least ideal for PICC?

Answer: Cephalic vein

While the cephalic vein can be used for PICC insertion, it is generally considered less ideal than the basilic or brachial veins. The cephalic vein often has a smaller diameter, a more tortuous course, and can be more prone to venospasm, making insertion more challenging and increasing the risk of complications like phlebitis or occlusion. Therefore, it is typically avoided if other options are available.

Where should PICC tip terminate?

Answer: Lower third of superior vena cava

The ideal tip termination for a PICC is in the lower third of the superior vena cava (SVC), just above the cavoatrial junction. This placement ensures that infused medications are rapidly diluted by the high blood flow in the SVC, minimizing irritation to the vessel wall and reducing the risk of complications like cardiac arrhythmias or vessel erosion. Correct tip placement is critical for safe and effective therapy.

Why evaluate arm circumference?

Answer: Check for thrombosis

Regular measurement of the arm circumference above the PICC insertion site is a vital assessment for detecting potential complications, particularly deep vein thrombosis (DVT). An increase in arm circumference can indicate swelling caused by a thrombus forming in the vein, which can impede blood flow and lead to pain and further complications. Early detection allows for prompt intervention.

Which diagnostic tool guides vein selection?

Answer: Ultrasound

Ultrasound is the preferred diagnostic tool for guiding vein selection and insertion during PICC placement. It allows for real-time visualization of the veins, enabling the clinician to assess vessel size, patency, and course, as well as identify any anatomical variations or existing thrombi. This guidance significantly improves insertion success and reduces complications compared to blind insertion.

What is the function of valves in veins?

Answer: Prevent backflow of blood

Veins contain one-way valves that play a crucial role in venous circulation. These valves open to allow blood to flow towards the heart and then close to prevent the backflow of blood, especially against gravity. This mechanism ensures efficient venous return and prevents pooling of blood in the extremities, contributing to overall circulatory health.

Which layer lines the inner surface of veins?

Answer: Endothelium

The endothelium is the specialized epithelial tissue that forms the innermost lining of all blood vessels, including veins. This smooth, non-thrombogenic surface is crucial for preventing blood clots and facilitating the smooth flow of blood. It is the direct layer in contact with the blood within the vein.

What anatomical landmark is used for measuring catheter length?

Answer: From insertion site to SVC

Accurate measurement of a PICC line is essential to ensure its tip rests in the superior vena cava (SVC), which is the optimal location for central venous access. Measuring from the insertion site to the SVC ensures the catheter is long enough to reach this central vessel without being too long or too short. This prevents complications and ensures proper function for medication delivery or blood sampling.

Why is the basilic vein preferred?

Answer: Fewer valves and larger diameter

The basilic vein is often preferred for PICC insertion due to its anatomical advantages. It generally has a larger diameter compared to other arm veins, allowing for easier catheter insertion and better blood flow around the catheter. Additionally, it typically contains fewer valves, which reduces the risk of encountering resistance or damaging valves during catheter advancement.

How is vein patency assessed?

Answer: Compression and refill under ultrasound

Assessing vein patency is crucial before PICC insertion to ensure the chosen vein is suitable and free of obstructions. Using ultrasound, the vein can be visualized and compressed; a patent vein will compress completely and then quickly refill with blood when pressure is released. This method directly confirms the vein is open, free of thrombi, and has adequate blood flow.