GIVE ME MY BEAUTIFUL CLOTH HATS OR GIVE ME DEATH!!” tweeted a pediatric anesthesiologist last May. This ultimatum, along with similar sentiments from others, carried the hashtag #BanTheBouffant, a call to arms over surgical headgear that began circulating in October 2017.

These health care professionals were expressing distaste at being forced to wear the bouffant cap rather than surgeons’ traditional cloth cap, a surprisingly heated controversy steeped in questions of tradition, safety and regulatory interference. Writing on his blog, Science-Based Medicine, in August, surgical oncologist David Gorski dubbed the situation “a no-holds-barred cage match.”

In one corner are the majority of surgeons and anesthesiologists, who defend the cloth caps they have used for decades. The tight-fitting garments, familiar to the general public from decades of hospital TV dramas, are often purchased by the surgeons themselves and sometimes customized with a favorite pattern or sports team logo.

In the other corner is the Association of periOperative Registered Nurses, a standard-setting body that, in 2015, updated its operating room guidelines to recommend “head covers or hoods that confine all hair and completely cover the ears, scalp skin, sideburns and nape of the neck.”

In practice this means bouffant hats, disposable caps that resemble a voluminous hair net. Surgeons and surgical nurses complain that the bouffants are hot, environmentally wasteful (they can’t be reused) and make headlamps, loupes and other functional headgear slip during surgery. But many argue that the bouffant, which can be pulled over even long hair, as well as the ears, better protects against infection risk.

At the heart of this debate are questions about what causes infections in and around surgical sites. Approximately 300,000 surgical site infections (SSIs) occur each year, accounting for approximately 20% of hospital-acquired infections. These SSIs lengthen patients’ hospital stays by an average of five days and raise costs by $500 a day, totaling $750 million a year. Some SSIs can lead to death, particularly for vulnerable patients. Many of the infection-causing bacteria live in human hair and skin and can be shed into the environment. But there isn’t conclusive evidence about whether and under what conditions those bacteria may find their way to an open surgical wound.

Lisa Spruce, director of evidence-based perioperative practice at AORN, says the group made its revised recommendation in 2015 after a review of the evidence. She concedes that there was little data available in 2015, and no clearly established link between perioperative team members’ hair and surgical site infection. Yet because the risk seemed high, AORN felt definitive evidence wasn’t required, she says.

Many surgeons beg to differ. This is about “unilateral decisions not supported by any type of vigorously tested data,” says Troy Markel, a pediatric surgeon and professor of surgery at Indiana University. To fight back, he and many other surgeons have done their own research, producing several studies of thousands of patients that looked at infection rates based on the surgeon’s cap type and before and after the guideline change.

One review, “Naked Surgeons? The Debate About What to Wear in the Operating Room,” noted the imperfect application of evidence on hospital room attire, especially the fact that clothing appears to rub off dead skin, which would imply that unclothed surgeons shed fewer bacteria than those wearing scrubs. Another study, comparing bearded surgeons with those who were clean-shaven, showed zero difference in bacterial shedding.

In a third study, led by Markel, an OR team wore three different types of hats—disposable bouffants, disposable skull caps and cloth skull caps—while performing several one-hour mock operations on a piece of raw steak. Markel and his colleagues observed higher microbial “shed” from the bouffants than from the other two types of cap. The team is looking for funding to do more research.

Markel admits there is also an emotional component behind this passionate support for cloth caps. For many surgeons and nurses, the hats are seen as a fun form of personal expression that can lighten up an otherwise heavy mood in a hospital setting. “To be told that you’re not allowed to wear those caps really kind of put people down,” he says. (A survey by the American College of Surgeons suggests this decline in morale was real and may have been widespread.)

In February of this year, AORN met with the American College of Surgeons, The Council on Surgical and Perioperative Safety, the American Society of Anesthesiologists and The Joint Commission, the accreditation organization that also conducts hospital inspections, to discuss operating room attire. In May, those groups put out a joint statement: “Over the past two years, as recommendations were implemented, it became increasingly apparent that in practice, covering the ears is not practical for surgeons and anesthesiologists and in many cases counterproductive to their ability to perform optimally in the OR.” The Centers for Medicare and Medicaid determines hospital attire, but it typically follows AORN’s recommendations.

On October 24, AORN issued a news release summarizing anticipated changes to its operating room attire guidelines in 2019, including removing the requirement for total ear covering and leaving many decisions about specific types of OR attire to individual hospitals. Proposed guidelines will be released for public comment in January.

In the meantime though, the rules have not changed. “The policy process takes time and making changes isn’t always easy,” says Mary Brandt, a pediatric surgeon at Texas Children’s Hospital in Houston and a wellness blogger. She says she hopes that the evidence, tradition and policy will align at her hospital, allowing the cloth cap to regain its place in operating rooms.