Insertion of a catheter causes a rise in catecholamine levels in some people. This interferes with test results, so catheter is inserted the day before the test. You stand for 10 minutes. A second blood sample is collected from the in-dwelling catheter. Catheter is removed.
Adhesive bandage is applied to catheter-insertion site.
After the test Immediate post-test care Apply pressure to the puncture site with cotton provided by the laboratory. If a vein has been punctured, raise your entire arm over your head while applying pressure. Some discoloration, soreness or swelling may develop at the venepuncture site. This responds well to moist, warm compresses applied every 2 to 4 hours. Activity after test Resume taking any medications that were withheld before the test.