Under Pressure

By Roberta Staley
Photography Greg ehlers

For divers, the ocean off British Columbia’s west coast holds many wonders, from mischievous sea lions nipping at scuba fins to wolf eels soliciting chin scratches to cavorting white-sided dolphins showing the ungainly human how swimming is really done.

For Sherri Ferguson, the ocean is an enchanting place that appeals not only to her fascination with diving and the ocean’s many inhabitants but her passion for science. Since she became director of the Environmental Medicine and Physiology Unit at Simon Fraser University in 2009, Ferguson has merged these two loves, immersing herself in a complex and highly specialized area of science – investigating what happens to the human body when taken to extreme depths or heights that, physiologically, Mother Nature never intended it to go.

Before coming to SFU as a staff member, Ferguson was – and continues to be – one of Canada’s most respected professional divers and dive instructors. Her activities within the diving community run the gamut from diving safety officer for the Universities of Victoria and British Columbia to executive positions with groups like the Canadian Association for Underwater Science, where she is the current vice-president. In addition to such stellar qualifications, Ferguson is also a master’s student at SFU in the Department of Biomedical Physiology and Kinesiology.

The “Dr. Watson” to her scientific investigations is, interestingly, not flesh and blood, but massive, white, and metal: two hyperbaric chambers, stacked one on top of the other, that were built more than four decades ago by the Perry Submarine Company and brought to the university in 1981 to facilitate research into the effects of pressure change on humans. The main chamber fits up to seven people, housing them for anywhere from several hours to a day, week, or month to test the short- and long-term physical effect of extreme atmospheres, which is a key concern for pilots, astronauts, and commercial divers. The lower chamber can be filled with water, fitting two subjects in scuba gear, allowing Ferguson to conduct tests that mimic the real-life pressure changes divers encounter underwater.

Ferguson’s experiments in the laboratory, which is located in the Shrum Science Building on the eastern side of Burnaby Mountain, is intertwined like DNA with her graduate research. She is immersed in a slightly obscure area of science called cellular hyperbaric electrophysiology, which seeks to understand how human cells function when elements like oxygen are transformed by atmospheric pressure changes from the elixir of life into a deadly toxin. Ferguson explains that if scientists understand at the molecular level how human cells react to pressure changes, they can develop pharmacological approaches that mitigate the physical reactions suffered by those working at extreme depths or heights.

From the depths of the sea, to Earth's highest peaks, to Mars – all at SFU.

“We can simulate the Martian atmosphere in the hyperbaric chamber,” says Ferguson, who co-authored a paper for the journal Aviation, Space, and Environmental Medicine analyzing fluctuations in cognition when the body is hypoxic (suffering low oxygen levels) at altitudes of 5,334 metres and 7,620 metres, heights achieved by commercial and fighter jet pilots. Ferguson also co-authored a paper in the Journal of Applied Physiology that looked at acute mountain sickness, which is caused by a lack of oxygen at high altitudes and has stopped many a mountain climber dead – sometimes literally – in their tracks.

Ferguson’s workload as a lab director, graduate student, and single parent to boys is Sisyphean, made all the more stressful by an additional pressure: holding the future of the Environmental Medicine and Physiology Unit in her hands. When she first arrived at SFU in 2007, the hyperbaric chamber laboratory had fallen not only into disrepair but disrepute. Under administration of the Department of Kinesiology, which later morphed into the Department of Biomedical Physiology and Kinesiology, the lab was earmarked for obsolescence because it was expensive to maintain and rarely used.  But for Ferguson, mothballing the hyperbaric chamber would be tantamount to mothballing the Mona Lisa, so she created a comprehensive business plan and gave it to the head of kinesiology, promising that she could turn the lab into a source of profit as well as prestige for the university. The rest, as they say, is history.

Ferguson opened the lab up to the public – divers and pilots – who were willing to pay to experience the physical phenomena associated with pressure changes in a controlled setting. Divers who work more than 300 metres below the ocean surface cope with two main dangers from pressure change: the “bends” and nitrogen narcosis. The bends happen when there is a rapid reduction in pressure, such as a too-quick ascent to the surface. This can spark joint pain, paralysis, stroke-like symptoms, heart attacks, and even death, says Ferguson. High-altitude pilots and astronauts experience different problems. The hypoxia they suffer from low oxygen can cause fainting and pulmonary or cerebral edema when fluid accumulates in the lungs and brain.

Nitrogen narcosis occurs under high pressure, when the mixture of oxygen and nitrogen that divers inhale from air tanks acts like a narcotic, causing intoxication equal to a Friday night’s worth of martinis. It is so mentally debilitating that divers have been known to swim down instead of up at the end of a dive, with deadly consequences. However, if they experience this disorientation in a safe setting, they learn how to react appropriately. “They experience the signs and symptoms first hand and recognize it if it happens,” Ferguson says.

The experience in the hyperbaric chamber is not only educational for divers but provides Ferguson with an opportunity to conduct her research; the subjects are happy to be guinea pigs, and the information gathered forms the basis of her published studies. SFU’s hyperbaric laboratory is one of only two such facilities in the country; the other is located at Defence Research and Development Canada in the Downsview area of Toronto and used exclusively for deep-diving studies.

Increasingly, Ferguson’s research into cellular hyperbaric electrophysiology has medical applications: she is looking at the efficacy of low- and high-pressure treatments for traumatic brain injuries, autism, and diabetic neuropathy and problem wounds of the lower extremities. Currently, there are 15 recognized uses of hyperbaric oxygen therapy (HBOT) that can be billed through B.C.’s Medical Services Plan. These include the treatment of wounds, carbon monoxide poisoning, osteomyelitis (bone infections), and decompression illness in divers. Patients being treated breathe 100 percent oxygen at high pressure – double what it is at sea level – and this elevated pressure forces the oxygen to bond to hemoglobin, a red protein in blood that transports oxygen around the body.

HBOT, however, is also being touted by alternative therapy pundits as treatment for a plethora of ailments ranging from hair loss to dementia to erectile dysfunction. Michael Jackson, for example, slept in a hyperbaric chamber, believing it would provide a Fountain of Youth. Ferguson worries that a lack of oversight by Health Canada leaves HBOT open to abuse. There is no proof, for example, that it helps cure autism, yet many desperate parents of autistic kids spend large amounts of money on HBOT. “We need to run trials to determine if things like autism, stroke, or traumatic brain injury are improved by this therapy.” A bigger concern is safety: oxygen under pressure is highly flammable and the teeniest bit of static electricity can spark a conflagration within a chamber, with horrifying results. Such cases, while rare, occur often enough to warrant stricter regulation of operators, Ferguson says.

High-performance athletes also use hypoxic tents to mimic training at high altitudes. Thin mountain air causes the body to increase production of oxygen-carrying red blood cells. By sleeping in a low-oxygen chamber, the athlete’s body produces these cells, theoretically enhancing performance. This so-called hypobaric therapy is considered unethical, although the World Anti-Doping Agency doesn’t ban it.

Several years ago, the laboratory’s capabilities and Ferguson’s professionalism and hard work drew the attention of the United States Navy Experimental Diving Unit. As a result, the U.S. Navy is sending one of its officers, Lieutenant Commander Denis Colomb of Florida, to SFU for a three-year study as a diving researcher and liaison for the Canadian Navy, as well as a visiting professorship. (His stay is being funded by the U.S. Office of Naval Research Global (Americas) and the Office of Naval Research Undersea Medicine Directorate.)

Colomb says that the research, which focuses on how gases at increased atmospheric pressure work at a molecular level in the human body, will have practical applications in the future, specifically to enhance the depths undersea divers can go. Scuba divers don’t swim much below 30 metres, but saturation divers live underwater at depths greater than 300 metres for 28 days at a time. This type of dive work is required for monitoring the integrity of deep-sea gas and oil wells. “It is also important for operational missions and intelligence operations, since our competition is extending their spheres of influence,” says Colomb.

With such a vast and ambitious array of research projects on her plate, Ferguson rarely has time to dive in the ocean anymore. But its blue beauty is always lapping on the periphery of her consciousness, inspiring her work into the mysteries of this intriguing but dangerous world.

Photo montage: Jane Edwards Griffin