|Faces of HCMC // Hyperbaric chamber |
Here’s a riddle: where Downtown can you go 66 feet below sea level with a former scuba instructor?
You can’t go that deep in Loring Lake. But if you suffer from carbon monoxide poisoning, a radiation injury or decompression sickness, you can take the plunge in HCMC’s hyperbaric oxygen chamber, a steel-enclosed vessel that replicates the physiological effects of a deep-sea dive.
Housed inside a squat brick building just off of the hospital’s main campus, the hyperbaric oxygen chamber is essentially a virtual submarine. Originally built in 1963, it’s the oldest piece of medical equipment in the hospital, predating even the main HCMC building.
The command center, where a “driver” operates the chamber, looks straight out of a World War II movie, with a dashboard of glowing buttons and a slew of pressure gauge dials. Old-fashioned valve wheels protrude from a wall in the rear of the facility. The entire staff has the Navy diving tables memorized, and an air lock system allows nurses to pass medical equipment to the technicians inside.
Patients enter one of four chambers, the largest of which can accommodate up to nine people, where they experience moderate to intense atmospheric pressure while breathing 100 percent pure oxygen through a mask. Patients suffering from a cancer-related radiation injury or from a diabetic foot wound most commonly undergo the treatment. In both cases, anaerobic bacteria, organisms that thrive in low-oxygen environments, eat away at tissue, causing wounds that refuse to heal. The blast of oxygen a body receives in the chamber kills such bacteria.
“Oxygen is the medicine here. What we do is we allow your body to take in thousands of times more oxygen than it normally would,” said Sam Weekes, a hyperbaric technician who used to work as a scuba instructor. For a routine radiation injury, he said a patient would “dive” to 46 feet below sea level — equivalent to 2.4 times Earth’s normal atmospheric pressure — and stay there for a little under two hours.
“You feel it in your nasal passages and ears,” said Weekes, who breathes normal air, comprised of 80 percent nitrogen, when attending to a patient in the chamber. “If you don’t plug your nose, it’ll start to hurt by the time we’ve reached 10 feet.”
Resurfacing must be done gradually, just as in a real submarine, or techs and patients can get decompression sickness, or “the bends.” The chamber has treated patients suffering from this excruciating ailment, the recovery from which requires a five-and-a-half-hour stint at 66 feet below sea level.
HCMC’s hyperbaric chamber is the only one in the state that is open 24/7 for emergencies — a rarity in the nation. That means that pretty much any emergency case of carbon monoxide poisoning that occurs in the Upper Midwest winds up in Downtown Minneapolis. Up to 3,100 patient treatments take place in HCMC’s hyperbaric chamber every year.
Dr. Cheryl Adkinson, director of hyperbaric medicine, pointed out that a small chamber exists at Abbott Northwestern Hospital and that the Mayo Clinic has a very nice one. But “we were the only facility in Minnesota for 45 years,” she said. The HCMC chamber, she said, “serves all of Minnesota.”
In late June, the Hennepin County Board of Commissioners approved funding for a $9.85 million replacement for the near 50-year-old facility. Once begun, construction of the new hyperbaric chamber will take around three years.