Which lumen color is typically used to draw blood from a central line?

• A. Brown or Red lumen
• B. Blue lumen
• C. Green lumen
• D. Yellow lumen

Answer: (A)

Central venous catheters have multiple lumens, each color-coded to indicate its use. To obtain an accurate blood sample, you should draw from the lumen designated for blood collection so the specimen isn’t contaminated by medications or nutrients being infused through other lumens. In many systems, that lumen is colored brown or red. The color cue helps staff quickly pick the correct lumen, especially in urgent situations. Drawing from lumens colored blue, green, or yellow can risk sample contamination from infusions, meds, or TPN, leading to inaccurate results. Always follow your facility’s protocol and flush as required before and after drawing.