Using a marker is a necessity for surgical site marking, either to write the physician's initials or a "yes" - the only two types of site identification that are acceptable on their own (see "The Right Ways to Prevent Wrong-site Surgery," page 20, July 2005). But should you use sterile or non-sterile markers for this practice?

What's your prep practice?
Whether to use a sterile marker depends on whether you subsequently "sterilize" the surgical site with a 7.5% povidone-iodine scrub followed by the application of a 10% povidone-iodine paint or some similar process (such as Betadine, pHisoHex or Hibiclens). It also depends on where you do the marking. Obviously, if you mark the site when the patient is in the OR, you should use a sterile single-use pen.

In order to follow recommended protocol that the patient be involved in the verification and marking of the surgical site, you might want to perform the site identification outside the OR, before the patient is significantly sedated. Further, when the patient is still in pre-op, he'll probably be less nervous than he would be if you were confirming the surgical site with him in the OR.

Infection comparison
There's no evidence to show that non-sterile markers pose an increased infection risk to patients. In a study last fall, forearms were marked with a non-sterile surgical marker; as a control, the other arm wasn't marked. Both upper extremities were then sterilized with the aforementioned combination of povidone-iodine scrub and paint.

Researchers used swabs to obtain samples from the experimental as well as from the control arms. They then sent the swabs for microbiological culture and analysis. The result: no growth in the cultures of the swabs used on either the experimental or control arms.1

There is also no evidence in the literature that markers have transmitted disease from one patient to another. But use your common sense: If you're marking the surgical site, and the patient has broken skin or is known to have a communicable skin disease, you should throw out the marker after that use.

So the key feature of any surgical site marker is that it's scrub-resistant, meaning it will stand up to the scrubbing of the skin inherent in the prepping process without fading or washing away. The VA National Center for Patient Safety recommends you use any non-toxic marker that won't wash off when the site is prepped, including "special-order self-inking rubber stamps to mark sites" used by "some non-VA hospitals."2

Beware strange smells
Don't use any marker not FDA-approved for surgical use. Also, try to be aware of the potential effects of surgical markers: A study performed on laboratory mice using eight non-sterile marking pens found that emissions from all eight of the pens produced behavioral abnormalities such as altered posture and gait, tremors, falling and hyperactivity.3

The exposure concentrations were similar to the total volatile organic compounds values near marking pens in actual use. Researchers used gas chromatography to identify mixtures of alcohols, acetates and ketones, and documented that some marking pens can emit mixtures of chemicals that can produce acute respiratory toxicity and acute behavioral abnormalities in normal mice.

They provide a toxicological explanation for some of the human complaints concerning respiratory and neurological reactions to marker emissions. If you've experienced these sorts of problems, marker fumes might be the reason, so you might want to take care to use the markers in a well-ventilated area or to test several kinds of markers to decide which to use. No similar studies have been performed on sterile markers.

Proceeding with site ID
Using a new sterile marker for each patient will increase your costs (one company's sterile, single-use marker sells for 36 cents apiece). In most cases, a non-sterile marker will do without increasing risk of infection. But, to ensure infection control and patient safety, you should restrict the marking of the surgical site to the physician who'll be performing the surgery or another privileged provider who'll be scrubbed in as part of the OR team and scheduled to be in the OR for the procedure.

References
1. J Bone Joint Surg Am. 2005 Oct;87(10):2193-5
2. "Frequently Asked Questions (FAQs) Regarding the Ensuring Correct Surgery Directive." VA National Center for Patient Safety. 10 Nov. 2005. http://www.patientsafety.gov/FAQ.html#CorrectSurg
3. J Toxicol Environ Health A. 2003 May 9;66(9):829-45.