Author(s): Angelo Verzoni. Published on January 2, 2018.

Comfortably Numb

How a new chapter on dental gas and vacuum systems in NFPA 99 can help practitioners, AHJs, and others protect against the hazards associated with sedation


In the spring of 2009, Austin Stone was a high school senior in Tonganoxie, Kansas, a town of about 5,000 people nestled in the northeastern corner of the state. He was an athlete, a runner, and, like many teens, he needed to have his wisdom teeth removed. On march 30, he went to a dental office in nearby Lawrence for the surgery.

A year later, Stone was “learning to live again,” as a local newspaper put it. After suffering brain damage during the surgery, the 19 year old was left partially blind, hard of hearing, and with limited gross motor skills.

Related Content

Digging into Dental:
Five things accomplished by NFPA 99's new chapter on dental gas and vacuum systems.

According to articles published by the Lawrence Journal-World, the oral surgeon performing the operation, Dr. Kirk Vincent, had first tried to sedate Stone with nitrous oxide, commonly referred to as laughing gas, through a nasal mask. But there was a problem. The gas lines of nitrous oxide and oxygen, which is administered along with nitrous oxide in a 1:2 ratio, were crossed. When Stone didn’t become sedated, since he was inadvertently receiving more oxygen than nitrous oxide, Vincent administered a mixture of intravenous drugs that are commonly used to sedate patients. The drugs worked, and Stone’s heart rate started dropping. Then, Vincent administered what he believed to be pure oxygen through the mask, which in fact was pure nitrous oxide. When nitrous oxide is administered without the proper balance of oxygen, it can cause brain damage and even death.

Austin Stone speaks to reporter

Austin Stone, a Kansas teenager, suffered brain damage in an incident involving dental gases and intravenous sedation drugs. Photograph: Lawrence Journal-World

In recent years, sedation has become a more common aspect of dentistry in general, not just for oral surgeries like the extraction of wisdom teeth. The rise of sedation dentistry—specifically when it includes deep sedation or general anesthesia, which render patients close to or entirely unconscious—means dental gas and vacuum systems must be given the same level of scrutiny that medical gas and vacuum systems are typically given to prevent deaths and injuries.

One of the first steps to achieving this will be building an understanding among practitioners, authorities having jurisdiction, and those who sell and install dental gas and vacuum systems around the high level of sedation that is occurring within many dental facilities. Also integral to that effort is a new chapter in the recently released 2018 edition of NFPA 99, Health Care Facilities Code, titled “Dental Gas and Vacuum Systems.” It’s the first time dentistry has been given its own chapter in the code, and experts hope the move will serve as a clear indication of the careful consideration these systems warrant.

“Dental systems have received little regulation compared to medical ones when it comes to NFPA 99,” said Neil Gagne, a medical gas verifier who is a member of the Piping Systems technical committee for NFPA 99 and helped write the new chapter on dental gas and vacuum systems. “There’s been so much effort dedicated to ensuring category 1 and 2 gas and vacuum systems that are found in hospitals, surgical centers, and urgent care centers are safe, and unfortunately not as much effort has been dedicated to the fast-changing dental industry. Most people are unaware of how complex the procedures are and varying level of anesthesia that dentists and oral surgeons are administering in an office setting.”

Serious sedation

In August, when Dr. Jonathan Wong, a dentist anesthesiologist, ordered vacuum pumps for his dental practice in Norfolk, Virginia, which specializes in sedation dentistry, he wasn’t happy with the equipment he received from the dental supplier. The pumps, which power dentists’ suction tools, weren’t as powerful as those provided by a medical supplier—what you’d find in, say, an ambulatory surgical center or a hospital. And that worried Wong.

While the lower-powered pumps can perform duties like sucking up blood, water, and fragments of teeth from a patient’s mouth—and are actually better in a more traditional dental setting—it’s risky to employ them in situations where patients are sedated to the point of unconsciousness, when they can be prone to aspirating. In fact, the pumps don’t meet NFPA 99’s criteria for use during the type of sedation Wong’s office performs. “What if a patient starts aspirating or has a blocked endotracheal tube? You need to be able to draw enough vacuum when you need it to be able to suction that out,” Wong said in an interview in November.

When he confronted the supplier about it, he said the response was along the lines of, “We didn’t realize you guys do this level of anesthesia.” It’s a common misconception, Wong said, despite evidence suggesting a rise in the use of anesthesia during dental procedures over the last 15 years or so.

A study published in 2012 in Anesthesia Progress, the journal of the American Dental Society of Anesthesiology, found that dental professionals in North America had noticed an increased demand for dentist anesthesiologist services from 2002 to 2012, particularly for procedures involving children. Wong thinks a number of cultural changes account for the spike. Foremost, he said, is a generation of parents that does not want their children to be “traumatized” by a trip to the dentist. “It used to be, if a dental procedure needed to be done, it was just done,” Wong said. “Times have changed. Now parents are saying, ‘I don’t want my child to remember anything from this.’”

A rise in office-based anesthesia has been seen across medical fields, not just in dentistry. “As a society,” Wong contended, “we’re requesting more anesthesia” for everything from tooth fillings to minor gastrointestinal procedures. The trend also reflects advancements in medicine that lead to more complex procedures. “As [gastrointestinal] procedures have become more complex and lengthy, additional medications became essential for adequate sedation. Oftentimes deep sedation is required for procedures such as endoscopic retrograde cholangiography [which combines an upper GI endoscopy with x-rays],” according to a study published in the World Journal of Gastrointestinal Endoscopy in 2013.

More of that anesthesia is being administered in office settings. When he first started in the industry 13 years ago, Gagne recalls that maxillofacial and oral surgeries that required deep sedation or anesthesia were done in hospitals, where there were anesthesiologists and a variety of patient safeguards and staff close at hand. “Then, two things happened,” Gagne said. “Hospitals got too busy and dentists and oral surgeons found it hard to secure operating rooms for their procedures, and the cost was often quite expensive when they did. So they started expanding what kind of anesthesia they were providing in their offices… The problem with that is, if something goes wrong during a procedure, like an adverse effect from anesthesia, that office setting doesn’t have the same safeguards in place that NFPA 99 requires for category 1 gas and vacuum systems that are found in most hospitals. More often than not they’d simply call 911. For me, that’s a scary situation.”

In dentistry, the trend has been rather grimly reflected by way of news reports of injuries and deaths in the dental chair. Prompted by the death of a 4-year-old boy in 2013, a 2015 investigative series by The Dallas Morning News estimated that a dental patient dies about every other day in the United States—a rough calculation based only on data from Texas, since many states fail to track data on patient morbidity and mortality in dental offices.

NFPA 99 and dentistry

Safety advocates stress that one of the best ways to prevent dental injuries and death is the use of NFPA 99. The code, however, does not have a long history of being correctly applied or even used at all in dentistry.

NFPA’s inclusion of medical gas systems in its codes and standards dates back to the 1920s, said Jon Hart, a principal fire protection engineer at NFPA and staff liaison to NFPA 99. Back then, the concern was primarily on flammable gases being used for sedation, such as ether. Over the years, as the U.S. phased out flammable anesthetics, NFPA’s involvement in medical gas and vacuum systems remained, and were addressed by NFPA 99, which was created as a compilation of numerous health care documents in the early 1980s. Today, commonly used medical and dental gases like oxygen can propagate a fire—there’s a case from the 1990s of a dental patient whose mustache rapidly caught fire after a spark created by drilling a cavity landed inside an oxygen-filled nasal mask—but they’re not flammable. Therefore, the chief concerns NFPA has for these systems, which are addressed by NFPA 99, are things like the crossed gas lines that caused brain damage to Kansas high schooler Austin Stone in 2009; vacuum pumps that might not be strong enough to stop an unconscious patient from choking to death; or systems that don’t automatically switch over to full gas tanks when the levels in existing tanks become too low.

For years, NFPA tried to fit regulations for dental gas and vacuum systems with the regulations for medical systems, but it simply didn’t work, according to Hart. There were inconsistencies with terminology, and it was difficult to determine how dental facilities should be classified using the same category or level system as hospitals and other medical facilities. The result over time has been less scrutiny given to dental gas and vacuum systems used for sedation than what’s been typically given to their medical counterparts.

“A normal building safety checklist that happens with hospital facilities or ambulatory surgery centers is the NFPA 99 med gas system checklist and verification, and that’s not happening in these dental offices,” Wong said. He remembers being told for years by medical professionals, enforcers, and others that the code didn’t even apply to dentistry.

The hope is that the new chapter can change things. For dental facilities requiring category 1 systems, which are defined as those that perform deep sedation and general anesthesia, the chapter says they must follow the same requirements as medical facilities that do the same when it comes to gas and vacuum systems. Valves, outlets and inlets, and piping for category 1 dental systems, for instance, must comply with sections of the general Gas and Vacuum Systems chapter, which facilities like hospitals follow.

The changes reflect what some experts have preached for years. “What I tell people is, the minute you take somebody across the line of consciousness, your entire office now becomes a medical gas facility, not a dental one,” said Dan Shoemaker, a longtime Piping Systems committee member with decades of experience in the dental service industry. “You no longer have patients who can just get up and walk out like they can with nitrous oxide.”

Much of the new chapter’s success will rely on understanding these different sedation levels, according to Shoemaker. Nitrous oxide, for example, doesn’t induce deep sedation; administering pure oxygen after nitrous oxide sedation allows patients to walk out of the office and drive themselves home. “This is such an important medication, and it’s very safe as long as you don’t have the gas lines crossed,” he said. More concerns arise as sedatives that further depress consciousness come into play. Shoemaker said one of the “scariest” trends he’s seeing is one involving doctors, known as mobile anesthesiologists, who wheel equipment into dental facilities that don’t have category 1 gas and vacuum systems in place and administer general anesthesia. “All of this is in clear violation to NFPA 99,” he said.

Gagne anticipates there might be some reluctance to follow the new rules among dentists who perform deep sedation or general anesthesia because of the potential cost of upgrading their systems.

But in some ways, the chapter will make it easier for dental facilities to comply with the code. New language has been added, for example, to distinguish dental air from medical air, the former of which doesn’t play a role in life support and therefore doesn’t require as much scrutiny. “But in some parts of the country, in the past, officials tried to enforce the same requirements for medical air on dental air that wasn’t being used in a medical way,” said Shoemaker, who also helped write the new chapter. “Now, it’s very clear that for dental air we don’t require the same level of verifying.”

The American Dental Association (ADA) also supports the new chapter, and provided input during its creation. “Prior to the creation of this dental-specific chapter, there was confusion regarding the application of NFPA 99 requirements to dentistry,” Dr. Dave Preble, vice president of the ADA’s Practice Institute, said in a statement provided to NFPA Journal. “In some cases they were misapplied, and in others they weren’t used at all in dental settings. The new chapter, when implemented properly, can help dentists protect patients by preventing gas and vacuum line malfunctions.”

Those who will likely see the benefits of the chapter first are the people who install, maintain, and inspect dental gas and vacuum systems, because they no longer have to wonder where to look to find information on dental facilities. All of the confusion that previously existed is gone, said Shoemaker, and ultimately that should translate to safer dental facilities for employees and patients alike. “With clarity comes safety,” he said.

ANGELO VERZONI is staff writer for NFPA Journal. Top Photograph: Lawrence World Journal