Although Vacutainer technology, which makes obtaining and handling blood specimens fast and simple, is widely used in the medical field, there are a few occasions when using a traditional syringe to draw blood is recommended instead.
Although Vactuainers can usually be used to draw a sample from a PICC line, they are not recommended for drawing through a Groshong catheter, because doing so can damage the valve on the catheter.
A patient who has very small or fragile veins may not be a good candidate for use of a Vacutainer, due to the potential risk of collapsing the vein. This is particularly true of veins in the hand. Pediatric and geriatric patients should be evaluated before the blood draw with this in mind.
Vactuainers are not recommended if the lab order is for four or more tubes to be drawn, again due to increased risk of vascular damage.
Patients who are unable to remain still during the blood draw may also be poor candidates for the use of a vacutainer.
Prior to teaching I spent twelve years in health-care as an RN working in emergency rooms and critical care units. I can honestly say that I have witnessed and performed venipuncture literally thousands of times. To the best of my knowledge, your scenario is rare. The fact of the matter is that blood is needed for study. How the operator chooses to retrieve the sample, ie., vacutainer or syringe, is essentially immaterial. Most of the time, it doesn't matter if the blood is venous or arterial. Unless, of course, you are drawing an ABG (arterial blood gas). There is something known as a capillary stick which uses a small pipette instead of a vacutainer, but this is done to get a sample of capillary blood not venous or arterial. I think the use of either a vacutainer system or a syringe is operator preference. Additionally, phlebotomy procedures can differ according to the facility the professional operates in.