I
Duke University
Medical Center
Intercom
VOL. 25, NO. 6
FEB. 10, 1978
DURHAM, N.C.
UNDERWATER WORK — A United States Navy diver prepares to enter a water filled chamber
known as the wet pot in the hyperbaric chamber. He and six other divers from bases across the
country are working with Duke scientists to devise decompression tables for new bubble-free
scuba gear. (Photo by David Williamson)
They could go home sooner
Nearly one-half of all heart attack
victims could shorten their hospital stays,
saving money and reducing the chance of
becoming "cardiac cripples."
That is the conclusion of three Duke
physicians in a report published last week
in the New England Journal of Medicine.
Drs. J. Frederick McNeere, Robert A.
Rosati and Galen S. Wagner concluded
that 45 per cent of the heart attack
victims could be sent home in one week,
reducing patient costs by an average of
$2,032.
Could save millions
The researchers estimated that
reducing hospitalization for these
patients could save the nation $360
million in medical costs annually.
McNeer, an associate in cardiology,
directed the study which was supported
by grants and a contract from the Health
Resources Administration of the
Department of Health, Education and
Welfare.
Rosati and Wagner are associate
professors of cardiology.
One week often sufficient
The researchers concluded that people
who have had heart attacks can go home
after about seven days if they have not
suffered serious complications by their
fourth day in the hospital.
Ordinarily, these patients stay in the
hospital an average of 16 days.
Besides having smaller medical bills,
the heart attack victims will be
psychologically better able to resume
their normal lives if they spend less time
in hospitals, the study concluded.
According to a national survey, 394,000
Americans have heart attacks each year.
(Continued on page 2)
Duke researchers go diving
for new decompression tables
The United States Navy has awarded a
$185,000 research contract to a Duke
scientist to devise decompression tables
for a new electronically controlled
underwater breathing device.
The device, developed by BioMarine
Industries, replaces traditional
compressed air tanks with a backpack that
recirculates the gas a diver breathes
rather than releasing it into the water as
bubbles.
Dr. Richard Vann, assistant medical
research professor of anesthesiology,
received the contract. He said the main
advantage of the new equipment is that it
will allow a free diver to remain
underwater for as long as six hours
regardless of depth.
Even scuba divers
have to come up for air
"Compressed air scuba gear currently
being used limits a diver to about an hour
underwater at shallow depths," Vann
explained. "And the deeper he goes, the
faster he uses up his air supply."
Previously designed rebreathing gear
has been limited to shallow water also, he
said, because the oxygen it uses becomes
increasingly toxic as pressure increases.
The new equipment is called the Mark I
Swimmer Life Support System. A
backpack contains two spherical tanks
about the size of cantaloupes, a canister
filled with soda lime that absorbs carbon
dioxide from exhaled air and electronic
components that regulate the supply of
fresh oxygen.
Because the system keeps oxygen at a
constant partial pressure, Vann said
toxicity is not a problem.
Rethinking decompression
"Special mixtures of gases are involved,
and as a result, existing decompression
tables are inappropriate," the scientist
said. Decompression tables are schedules
that show how quickly a diver can return
to the surface without contracting the
bends.
"We're also testing some of the
fundamental theories of decompression
sickness," he said. "There's a question as
to whether bubbles that cause the bends
start from small gas nuclei already in the
body or whether they develop after a
certain amount of supersaturation occurs
in diving."
Vann and his colleagues will use
ultrasonic scanners to monitor formation
of gas bubbles in experimental animals.
The scanners give cross-sectional
pictures of living tissue by means of high-
frequency sound waves.
Navy divers
A team of seven Navy divers from
bases across the United States is already
(Continued on page 3)
H
AND THE GROUNDHOG SAW HIS SHADOW—Last Thursday's snow produced scenes around
the medical center such as this view of the PDC entrance and Baker House from the hospital
lobby. The groundhog came out and went back in, but a lot of people stayed out, as shown on page
2. (Photo by ]ohn Beclon)