Updated: Published
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
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.
pielęgniarka, RN
490 Posts
So I was drawing labs today, had a pt, couldn't get antecubital to pop out so I went for the hand. After I got the needle in and good return the needle started to vibrate! I could even feel it on the top of his hand. It continued to do this as I collected what I needed and after I removed the tourniquet it stopped. Your thoughts on the cause? It was so strange, it felt just like the vibration when someone plucks a string on a guitar or something.