Vibrating veins

When the vein collapses a little bit, it can create some suction. Sometimes it can make the blood come back hemolyzed.

turbulent blood flow causes that vibration, perhaps your patient has some peripheral vascular insufficiency/disease. if this patient has some atherosclerotic changes in the vessels of this hand, then you occluding the vein with the tourniquet added an additional obstruction causing a greater turbulence which is the vibration felt

Ditto on the turbulent blood flow! I have had that happen and I had great blood return!

could it be a vasospasm?

Think about it this way. You have entered into a system of pressurized tubes (kind of like a garden hose) and before you entered that system you applied a tourniquet to congest a section of that tube...so it is really full and congested now,,,so you are pulling blood out now and the pressure will be released as you pull the blood out so sometimes it will vibrate as the pressure decreases. Sometimes if you are using a syringe to draw the blood that will vibrate too.......that means slow down your withdrawal or loosen or pop the tourniquet or the blood cells can break (HEMOLYZE). When you have a venous spasm your blood flow usually stops or slows significantly.

Lab results came back yesterday eve and the speciman was not hemolyzed or anything, thank goodness. I'll take off the tourniquet next time this happens. Thanks for the replies!

sfreck1214......First try slowing your blood withdrawal...just keep it coming slow and steady...or switch to a smaller syringe...if still vibrating the loosen or pop tourniquet....b/c you do not want to slow the flow down to much.