FAR ENOUGH It's a good idea to stay as far away from the imaging source as possible, but numerous studies indicate that exposure levels are reduced to safe levels at a distance of 6 feet.

If you're concerned about the dangers faced by staff who work with C-arms, you'll be interested in AORN's recent update to its Guideline for Radiation Safety, which offers new ideas for protecting surgical personnel from imaging's invisible dangers. Here are some of the highlights.

1. There's no need to leave the room
The consequences of radiation exposure may not become apparent for years, but if and when that reckoning occurs, it can be devastating. Most recommendations and standards regarding radiation safety are rooted in common sense. For example, OR teams have subscribed for years to the concept of capturing images with ALARA (as low as reasonably achievable) exposure. The importance of shielding both practitioners and patients with protective coverings is widely known. And you likely know that personnel who routinely work around C-arms and other radiological devices should have their exposure levels monitored.

But a commonly asked question is whether personnel in sterile attire need to leave the room when radiation-emitting devices are being used. The answer is no. Typically they need only be about 6 feet away from the source, or a little farther if the source isn't angled straight up and down.

The collective evidence, taken from more than 20 sources, establishes that the radiation dose received by personnel decreases dramatically as the distance from the source increases. That's due to a principle known as the inverse square law, which states that, for example, when the distance between the person and the source is doubled, the exposure is decreased by a factor of 4 (2 squared) and when the distance is tripled, the dose is decreased by a factor of 9 (3 squared).

Six feet is considered the distance at which exposure is decreased to a safe level (but many state and local regulations require all personnel in the room to use some form of shielding). The bottom line: Personnel should always stay as far away as possible from the radiation source and limit the amount of time they spend close to it, but there's no need to leave the room and increase risks of outside sources contaminating the OR. If someone must leave during a procedure, rolling lead doors provide excellent protection and decrease the likelihood that the sterile field will be contaminated.

EQUAL PROTECTION Lead aprons have long been the standard, but lighter aprons made from tungsten-antimony and bismuth-antimony are just as effective.

2. Monitor hand exposure
Staff and surgeons who routinely work within 1 meter (39 inches) of the primary X-ray beam should wear ring dosimeters to measure the amount of radiation their hands are exposed to. Traditionally, dosimeters have been worn on collars outside the protective apron, but that may not accurately register the amount of radiation that reaches the hands, which are especially vulnerable when, for example, physicians are holding instruments in the surgical field or injecting dye into the patient.

3. Shield eyes with lead
Personnel who are close to the radiation source should have leaded eye protection — leaded eyeglasses with wraparound side shields, ceiling-suspended shields or clear mobile shields that are taller than the person using them. The idea of having lead in eyeglasses is one of the newer concepts in radiation protection, but it's an important one. Think of it the same way you'd think about wearing goggles if you were working with dangerous chemicals.

4. There are lighter forms of protection
There's no question that protective aprons should be worn by all members of the perioperative team when a source of radiation is activated, but lead doesn't have to be the only choice. Lighter lead-equivalent materials, such as tungsten-antimony and bismuth-antimony, are equally effective and may be more comfortable when worn over longer periods of time. Strong evidence also supports the wearing of protective caps.

5. Pregnancy isn't a deal-breaker
There's considerable evidence that pregnant caregivers can be adequately protected when working around radiation, but they should still take extra precautions. In addition to following standard radiation protection techniques, wearing a maternity or double-thickness apron that's large enough to cover the entire abdominal area and back provides an extra measure of protection. Pregnant workers should also wear 2 dosimeter badges: one over the apron and one underneath, in the area of the abdomen. Additionally, pregnant staff members and physicians should be careful not to stand with their backs toward the radiation source. They do not, however, need to leave the room or be prohibited from participating.

Keep it up
Encouragingly, most facilities appear to be doing an excellent job of protecting caregivers. Many studies that examine dosimeters worn both outside and inside aprons show nearly zero exposure underneath, even when large amounts of radiation are detected outside. Keeping up with the literature and the latest safety guidelines helps make sure both staff and patients continue to achieve the highest degree of protection possible.