Graphic: Neil Rodd
Not many people spend their working days underwater but Port Lincoln abalone diver Neil Rodd knows that world well – and so much time spent underwater brings inevitable risks.
But a day like no other saw Neil confronted with two of the biggest risks – on the same day.
After spending two hours at depth collecting abalone, Neil began his very slow journey to the surface, a crucial procedure for divers so they can avoid decompression sickness, often called "the bends".
Too rapid an ascent causes the nitrogen naturally occurring in the body to form dangerous gas bubbles in the tissues and blood.
Symptoms of the resulting decompression sickness can include crippling joint pain, back pain, severe and sudden headache, tingling and numbness, dizziness, chest pain, disorientation, shock, paralysis, and stroke.
When immediate treatment is not available, decompression sickness can be fatal.
Graphic: Neil Rodd
On his way to the surface, Neil had paused at mid-depth to allow the nitrogen in his body to adjust to the changed pressure but as he did, another terrible risk presented itself.
"I felt chills," Neil says. "I looked over to my side and there was a white pointer swimming alongside me just three metres away and looking straight at me.
Neil Rodd (right).
"To give myself some protection, I swam back to the bottom and waited for 20 minutes, hoping the shark would disappear.
"Instead, more sharks turned up and I decided I just couldn't run the risk of attack, so I raced to the surface," Neil says.
Breaking the surface, Neil was immediately overcome by agonising decompression sickness.
Assessed by medical staff at Port Lincoln Hospital, it was determined that Neil urgently needed treatment in the hyperbaric chamber at Royal Adelaide Hospital (RAH).
The Royal Flying Doctor Service (RFDS) was alerted, and an aircraft soon left Port Lincoln with RFDS Flight Nurse Jodie Hunter providing Neil with crucial care in the air.
"I remember Neil well," Jodie recalls.
"He was in terrible pain and I constantly reassured him – our highest priority was to airlift him to Adelaide as quickly as possible."
Graphic: nel rodd ready to dive
The 650 kilometre drive from Port Lincoln to Adelaide takes more than seven hours, but the RFDS aircraft makes this trip in just 40 minutes!
People suffering the bends are highly susceptible to changes in air pressure, so a flight on board an aircraft that climbs to a normal cruising altitude, where air pressure is reduced, will make a patient's condition worse.
Neil Rodd (right) preparing to dive off Port Lincoln with a colleague.
In response to this unique set of circumstances – with patient care a top priority – RFDS pilots can employ a special strategy.
"The advanced capabilities of the Pilatus PC-12 aircraft used by the RFDS mean we can define and maintain a cabin air pressure equal to the pressure experienced at sea level," says RFDS Chief Pilot Damien Heath.
On arrival at the RAH, Neil spent periods inside the hyperbaric chamber over six days, breathing 100 per cent oxygen whilst under a raised air pressure, allowing the nitrogen gas bubbles in his body to gradually be absorbed and expelled by the body.
Neil made a complete recovery.