Being A Veterinary Vampire: Phlebotomy 101
Sometimes even the simplest procedures can get out of hand. Take drawing blood, for instance. That's when my work can start to resemble an episode of Dexter more than the elegant art of phlebotomy.
Like the time I was drawing up ten cc's of blood from an itchy kitty for an allergy screen. The syringe malfunctioned (really, it was not my fault) and blood went pouring down onto the floor. To the untrained eye, it looked as if I had just exsanguinated the cat. The owner was my plastic surgeon’s newest wife. She stared silently and ashen-faced at the pool of blood on the floor. Needless to say, I didn’t make a good impression on her that day.
This horror show was an exception, of course. Usually the bloodletting runs smoothly — even with fractious and freaky pets who might prefer you not pierce their skin with a needle.
Venipuncture, or phlebotomy (roughly interchangeable terms), is one of our most basic procedures. It is not necessarily an easy one, though. It takes months (sometimes years) of practice to learn how to do it right. The goal is to harvest the minimum quantity of blood required in as painless and efficient a manner as possible.
The process is simple:
- Place pressure on the vein upstream from the site you plan to puncture so as to limit its flow and thereby make it plumper and juicier (by placing a tourniquet or applying manual pressure).
- Wet the area with alcohol or disinfectant (shaving is optional unless an indwelling catheter is required).
- Find your vein by sight and/or by feel (palpate the vein with your finger to make sure it’s full and straight at the site you plan to puncture).
- Puncture the skin and vein with one easy movement (zen) and slowly pull back on the plunger.
Sounds easy, right?
Now I’ll tell you a few of the potential complications:
- The vein sometimes does not reveal itself. Even with the pressure of a tourniquet, sick, dehydrated, fat, or geriatric dogs might have veins that do not lend themselves to easy discovery. Hiding in fat or depleted of pressure, these are the nemeses of phlebotomists in both human and animal medicine.
- In breeds with crooked legs (dachshunds, basset hounds, etc.), the vein twists and turns so that the needle bangs against the walls of the vein instead of staying in the middle of it where the blood lives.
- The vein is so teeny tiny and/or weak that any pressure exerted by the syringe as it draws in the blood causes it to collapse (as when you try to suck up a Wendy’s Frosty through a Slurpee straw).
- Then there’s the moving target issue, when a pet is difficult to control. Ever try to thread a needle on a plane in heavy turbulence? No? But you get the idea.
And then there are the anomalies: like my syringe malfunction with the plastic surgeon’s wife. I’ll never live that one down.
Dr. Patty Khuly