Where does the tip of a centrally inserted catheter typically rest?

• A. Distal end of the inferior vena cava
• B. Distal end of the superior vena cava
• C. Right atrium
• D. In the subclavian vein

Answer: (B)

Placing the tip of a centrally inserted catheter in the lower part of the superior vena cava, near where it enters the right atrium, provides central venous access while minimizing risks. This location ensures rapid distribution of infused medications, reliable central venous pressure readings, and reduces the chances of causing arrhythmias or vessel injury that can occur if the tip sits inside the right atrium. The inferior vena cava is too low for central venous monitoring, and the subclavian vein is more peripheral, not the ideal central position. Placing the tip in the right atrium is generally avoided due to higher risk of arrhythmias and perforation.