Hennepin County wants new breathing room

The hyperbaric chamber at Hennepin County Medical Center (HCMC) in Minneapolis looks like a relic of a mad scientist movie.

Simple illuminated buttons and wall monitors that track temperature and humidity with quivering styluses are mounted on a hulking gray control panel. The cylindrical treatment chambers look and feel like a submarine, with 3-inch-thick steel walls, curved 2,000-pound doors, giant seams and bolts, and windows that look like the portholes of a old ship.

For almost 45 years the big machine reliably did its work, using pressurization and pure oxygen to save lives and heal the persistent wounds of people from all over Minnesota as well as Wisconsin, Iowa and the Dakotas. But in February, the chamber had to close for nine days when a backup compressor died and couldn't be fixed. This week, one of the chamber's compressors was a rented unit, supplied by a pulsing truck parked outside the building.

That's why Hennepin County commissioners are seeking $9.7 million to replace the hyperbaric chamber, which is the only such facility in the state used to regularly treat such emergency cases as people with carbon monoxide poisoning and/or divers with "the bends." It also offers therapeutic treatments for conditions such as wounds that won't heal, diabetic ulcers and tissue damaged by cancer radiation treatments.

"This has been used to provide unique services as part of the hospital mission for almost 50 years," said Mike Opat, a member of the HCMC board and chairman of the Hennepin County Board. "They treated 180 emergency cases in the last year -- that's an emergency every other day. In these tough economic times, this is not an investment a private hospital is going to make."

The Mayo Clinic in Rochester added a large hyperbaric chamber last year, but so far it has been used mainly for research and therapeutic treatment, an official said. The Hennepin County Board has requested federal stimulus money to replace the HCMC chamber and is also making a pitch for state bonding money at the Legislature. A new machine would cost an estimated $3.5 million; most of the rest of the money would be spent remodeling an area of HCMC to house the new chamber.

The existing hyperbaric chamber is a marine-blue steel hulk that has its own building at the corner of 5th Street and Portland Avenue, a block north of HCMC's main campus. While it looks like a period piece with its bulky monitors and igloo-like center node, the science behind the chamber hasn't changed since it was built on site as a research facility in the mid-1960s. The hospital bought it in 1991, though it had used it earlier than that.

When people breathe, they take in air that is about 21 percent oxygen, with nitrogen making up most of the rest, said Dr. Cher Adkinson, HCMC's director of hyperbaric medicine. In the chamber, patients wear masks that deliver pure oxygen. Pressurization -- the three treatment chambers can push pressure up to the level you would experience if you dove 198 feet deep in the ocean, though the maximum used for treatment now is the pressure you'd experience at a depth of 165 feet -- helps oxygen flow freely through blood and tissue.

Last year, 221 patients received more than 3,300 treatments in the chamber. Ninety-eight people were treated for carbon monoxide poisoning. The next-biggest group: 48 people with soft-tissue radiation injury from cancer treatments. Hyperbaric treatments can actually help people grow new blood vessels in damaged tissue, Adkinson said.

A handful of divers were treated for problems related to decompression illness, or "the bends." Some of the divers who have been treated at HCMC are vacationers who don't realize they're ill until they were on a plane headed home. Others have been sport divers who were in Minnesota lakes or water-filled quarries in Wisconsin, she said.

Though the equipment inside looks uncomplicated, with padded chairs or beds for patients, hose connections in walls and ceilings, and computer screens and telephones, care must be taken because oxygen is highly flammable. Much of the actual equipment -- the body of a computer, for example -- is outside the chamber. Anything that could produce a spark, including the inside of a flat-screen computer monitor and the bell of a telephone, is connected to a tube that coats parts with nitrogen to prevent fire. Things with moving parts, including watches, are banned from the chamber.

HCMC considered overhauling its hyperbaric chamber, but updating the antiquated equipment turned out to be as expensive as replacing it. The hospital also wants to move the chamber within its complex. People who need emergency hyperbaric treatments now have to be hauled by ambulance from the hospital to the site, which has no other specialized medical equipment on site.

Adkinson said a new chamber should run smoothly for another 50 years.

"We are a critical-care hospital, and what we do is not being done anyplace else," she said.

Mary Jane Smetanka • 612-673-7380