Equine hyperbaric oxygen chamber explosion in Florida kills woman and horse


Ocala, Fla. — Formal certification and new operating procedures for hyperbaric oxygen therapy may be on the way after a Feb. 10 explosion at a Florida equine rehabilitation center that killed a 28-year-old woman and a 6-year-old Thoroughbred gelding.

The cause of the explosion at the Kentucky Equine Sports Medicine & Rehabilitation Center (KESMARC) South Equine Rehabilitation Center has not yet been determined, but multiple agencies—including the Florida State Fire Marshal and the federal Occupational Safety and Health Administration (OSHA)—are investigating.

Deborah Cox, a spokesperson for the Fire Marshal’s office, says she can’t release any details, but confirmed the investigation is ongoing.

Michael Wald, a spokesperson for OSHA’s Region 4 office, also confirmed an investigation is underway, but says the agency has up to six months to issue a final report.

However, details about the explosion were listed in a Feb. 17 report released by the Marion County Sheriff’s Office (MCSO). The report states that emergency workers were called to KESMARC in Morriston, Fla., Feb. 10 just before 10 a.m. The facility—housed in a large metal barn—opened its doors in 2009 and contained a number of stalls within its hyperbaric oxygen chamber. The report notes that the entire end of the barn that housed the exploded chamber was marked by “total destruction,” and the body of 28-year-old Erica Marshall, a KESMARC employee, was found buried under the rubble.

KESMARC’s manager Leonora Byrne told authorities that Marshall was operating the chamber prior to its explosion, had done so for the past two years and was trained by the chamber’s manufacturer, Equine Hyperbarics (also known as Equine Oxygen Therapy and Veterinary Hyperbaric Oxygen). The horse being treated was from Stonehall Farm in The Plains, Va., and owned by Jacqueline Mars, according to a statement from the U.S. Eventing Association (USEA). The 6-year-old gelding’s name was Landmark’s Legendary Affaire, but was also known as “Tux,” according to USEA. USEA states that Tux was receiving a general wellness treatment in preparation for the upcoming competition season.

The MCSO report notes that, according to Sorcha Moneley—who was not an employee but observing treatments at KESMARC and injured in the blast—Tux had been in the chamber four times or so before. Some horses are given sedatives before entering the chamber, but Moneley told investigators that Tux had not had problems before and therefore was not sedated prior to his treatment. Later in the report, Moneley indicated Tux had been sedated prior to his treatment.

Moneley told investigators that Tux was being treated for equine protozoal myeloencephalitis (EPM) and that Tux had been in the chamber for about 22 minutes and was “unsettled.” Eventually, Tux kicked out sharp to his rear, knocking a lid at the rear of the chamber. The lid became dislodged and fell, revealing raw metal to the inside of the chamber, MCSO notes in its report. Tux, who was wearing steel shoes, dislodged protective padding inside the chamber and continued to kick and create sparks, and his steel shoes struck the metal inside the chamber.

Moneley says she and Marshall saw the sparks and then flames. That’s when Moneley left the chamber to call the fire department and Marshall began working to bring the chamber to its normal pressure. As she left the chamber, Moneley told investigators that she heard a small explosion followed by a second, larger explosion a moment later. She was about 20 feet away from the chamber when the blast occurred, knocking her down, Moneley says in the MCSO report.

MCSO’s report lists Marshall’s cause of death as blunt force trauma and thermal injuries as the result of an accidental explosion. There is no mention of the horse’s death in the report.

Moneley also told investigators she was aware of some problems with the valves on the chamber leaking and that Byrne had contacted the manufacturer about sending an engineer to look at the chamber. Moneley states in the report that the company told KESMARC it would send someone when it could, but that “she was aware of some heated emails and arguments between Ms. Byrne and the Kentucky facility concerning the hyperbaric chamber.“

Moneley was taken by helicopter to a nearby hospital following the blast and is now in fair condition. Funeral services took place for Marshall in Florida Feb. 17, and she will be interred in her home state of New Jersey.

Byrne did not return phone calls by press time, and Rob Miller—one of KESMARC’s owners—declined to comment on the explosion.

Kirsten Johnson, who owns the Kentucky KESMARC facility and is affiliated with Equine Oxygen Therapy, says she cut ties to the Florida KESMARC two years ago, but expressed her sympathies for Marshall and Tux.

“Our concern and our love goes to the family of the life that was lost,” Johnson says.

Despite rumors that Equine Oxygen Therapy has sent letters to veterinarians warning them to shut down their hyperbaric chambers, Johnson says no such letter has been sent.

“At this time, we’re in communication with the folks who have chambers,” Johnson says on behalf of Equine Oxygen Therapy. “We have been since it happened. At this point, until the investigation is done, our hearts go out to family of the life that was lost, the horse and the girl that was injured. But the investigation is ongoing. It would be irresponsible to talk about any of it until it’s complete.”Johnson says veterinarians who use the company’s chambers are well aware of what is going on.

“All of the veterinarians that own hyperbaric chambers have been contacted by the company,” she adds. “They own those chambers … and so are we making recommendations? Is everyone on heightened alert? Of course we are. Have we made any demands? No.”

“We are being responsible and we are moving forward in a responsible way and all the information we have and we can give, we’re there for them and we’re supporting everyone.”

When the time is right after the investigation is complete, Johnson says the company will provide more information about what happened and whether any changes will be made in terms of chamber operations. But nothing has been decided yet, she says.

Dennis Geiser, DVM, Dipl. ABVP, and director of hyperbaric services at the University of Tennessee’s Department of Large Animal Clinical Sciences, says hyperbaric therapy is used as both a primary or adjunctive therapy. The overall effect is to increase blood oxygen, pushing more oxygen into damaged tissue to assist with healing, he says.

In humans, hyperbaric therapy can be used to treat things like smoke inhalation and decompression sickness, but in animals, it is used more widely.

“In the animal world, since we don’t have third-party pay, we can treat a lot of different problems,” he says, listing conditions in horses like chronic wounds, joint infections, some neurologic problems, cerebral adema and laminitis.

Side effects can always occur in a pressurized environment, and sometimes animals will shake their heads or yawn to equalize pressure. Sometimes, therapists will then back off the treatment and proceed more slowly. Geiser says he has also heard of problems with bringing a patient back up from treatment depth too quickly, but he’s never seen it.

Sedation prior to using hyperbaric oxygen treatment is discretionary, he adds. Older chambers were small and sedation was often administered. But modern chambers are larger and allow horses to walk around, he says.

“If we know up front that the horse is kind of skittish or you get into a treatment and you find they’re not handling it well, we might stop and sedate them,” Geiser says, adding the decision is made on a case-by-case basis.

Until an official investigation is complete in the KESMARC case, Geiser says there is no way to know what caused the explosion.

Geiser says he is working to set up a veterinary hyperbaric medicine society as well as a certification program with an exam and set qualifications.

“We’re slowly trying to get people trained adequately,” he says.

Currently, there are courses across the country, including one he recommends in Texas. But there is no organization overseeing hyperbaric oxygen therapy and it requires no certification to operate a chamber. Many facilities don’t train operators outside of the training that is provided by a chamber manufacturer, he says. Geiser adds that many veterinarians on the small-animal side are now buying reconditioned human chambers for use with their animal patients.

“I don’t even have a handle on how many of those are around,” he says. “There are quite a few.”

But operating the chamber isn’t all that someone performing hyperbaric oxygen therapy needs to know, he says.

“It’s a lot more than just that. I’m not saying it’s a high-risk treatment, but it’s a little more technical and mechanically involved, so having some training is good and knowing the safety things and what it will work is a good idea,” Geiser adds.