A cutting-edge technology grows up
Children's
Hospital Boston looks back on 20 years of life-saving ECMO technology—and
how it's gone from a treatment of last resort to the
first line of defense.
More than 15 years separate patients Joe Alonzo
and Lexis Keller. But they are both alive and thriving today
thanks in no small part to the same lifesaving technologyóextracorporeal
membrane oxygenation, or ECMO. Together, Joe and Lexis represent
the past and present of an important mechanical support whose
use has steadily evolved at Children's Hospital Boston since 1984,
the year the hospital opened the first neonatal/pediatric ECMO
program in New England. Children's celebrated the 20th anniversary
of its ECMO program this year with a reunion for all the program's
survivors, their families and the hospital staff who took care
of them (see photos from the event throughout this story). Dream
Magazine thought it was the perfect time to take a look at where
ECMO started, where it's going and at the lives it's saved.
ECMO
defined
ECMO temporarily acts as a patient's heart and lungs while
he or she recovers from an underlying condition. It is comprised
of an intricate circuit in which a portion of the patient's blood
is removed through a tube and flowed through the ECMO machine,
where it is enriched with oxygen and pumped back into the body.
"On
September 11, we honor those who aren't here but should be. Today
we're also celebrating
these patients, who are here but shouldn't be." |
ECMO
is typically used in critically ill patients who haven't
responded to standard advanced life support (treatment with a
ventilator or medications) to help with their breathing and circulation
until a longer-term solution can be found. While it is the most
widely used form of mechanical heart-lung support in infants and
children, ECMO is not without risks. Patients may experience bleeding,
infection, blood clots or mechanical malfunction of the machine
itself.
The early days
Children's was the sixth hospital
in the country to launch an in-house ECMO program. The technology
was initially used to support infants who underwent reparative
surgery for congenital diaphragmatic hernia (CDH)óa birth defect
in which an infant's diaphragm doesn't fully develop. But in 1986,
just two years after the program's inception, a study conducted
at Children's showed that ECMO could also
help patients with persistent pulmonary hypertension (PPHN), which occurs when
a newborn's circulatory system doesn't adapt to breathing outside the womb.
The study reported a 97 percent survival rate in the PPHN infants supported
with ECMO.
Joe Alonzo was the study's third survivor 18 years
ago. He was born with PPHN, which caused him to inhale meconium
(the first stool passed in
utero),
and was immediately transferred to the neonatal intensive care unit, where
he was placed on a respirator. At 3 a.m. the next morning, the family was
approached about placing Joe on ECMO. "The doctors told us that it was a
highly experimental procedure, but that without it, Joey only had about a
20 percent chance of surviving," says
Lindsey Hurley, Joe's mother. "So of course we consented to put him on ECMO." Less
than a week later, Joe was on his way home, and today, the 18-year-old
has little more than a tiny scar to remind him of his brush with
death as an infant. "When
Joey was first born, he sounded like a little goat as he tried to gasp
for air," says
Lindsey. "It was a terrifying experience, but I am so thankful that we
took a chance on ECMO because it saved his life."
A change to heart
Toward the end of the 1980s,
cardiologists began considering ECMO to support the circulation
of children with heart disease, but that initially appeared all
but impossible due to one major complicationóbleeding.
"A patient's blood must be thinned so it can flow through the tubes and into
the ECMO machine," says Jay Wilson, MD, surgical director of the ECMO
Program. "But
by thinning the blood, you are essentially taking away its clotting ability,
which means there is a potential for internal bleeding.
"Oftentimes, newborns in physical distress experience
little bleeds into their brains, which normally stop on their own," he
adds. "But with a child
whose blood is being thinned, that bleed can keep going and eventually
turn fatal. This was especially true for cardiac patients."
Wilson
and his team began considering ways to stop bleeds in ECMO patients,
and came across aminocaproic acid (AMICAR), a drug that was already
being used in adults to decrease bleeding after heart surgery.
The Children's
team conducted a study in the early 1990s in CDH patients on ECMO,
determining that AMICAR had a significant impact on stopping bleeds.
It was then that cardiologists began to take an active interest in
using the drug in cardiac patients who needed ECMO.
"Since the introduction of AMICAR, cardiac disease
has become the number one indication for ECMO," says Wilson, explaining
that of the 50 to 60 patients put on ECMO annually at Children's,
approximately 60 percent of them require support due to a heart-related
issue.
Responding rapidly: Lexis' story
Following the
success of ECMO in cardiac patients, its use began to expand to
more complex cases, such as patients undergoing acute resuscitation
(the use of specialized techniques in an attempt to rapidly restore
an effective heartbeat). But prolonged resuscitation, when combined
with the amount of time needed to set up ECMO, proved risky, as
it increased the chance for significant damage to the brain, heart,
lungs and other organs. To address this issue, Children's
established ECMO Rapid Response in 1996.
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As part of this program,
an ECMO machine stands ready at all times in the Cardiac Intensive
Care Unit, and an ECMO specialist is on call 24 hours a day, seven
days a week. "We can
place a patient on ECMO within 30 minutes," says ECMO specialist
Nancy Craig, RT, explaining that respiratory therapists serve as
the technical gurus, managing the technology and being primarily
responsible for putting patients on ECMO. Children's currently
employs Rapid Response during acute resuscitation in about 50 percent
of cardiac patients requiring ECMO each year. Lexis Keller is one
such patient. Born with significant and complex congenital heart
disease, Lexi, as she is called by her family and friends, came
to Children's
in June 2004 for a biventricular repair to fix her heart defects.
Following what appeared to be a successful eight-hour operation,
Lexi took a turn for the worse, going into cardiac arrest minutes
after surgeons closed her small chest.
Acting quickly to stabilize
her, the Rapid Response team placed Lexi on ECMO, while physicians
and nurses worked to resuscitate her. "I'll
never forget how hard everyone worked to save my daughter's life," recalls
Danielle Keller, who didn't see her daughter until four hours later. "They
were so fast and efficient, and no one ever gave up on her."
Lexi
remained on ECMO for 29 daysóthe longest any Children's patient
has been on the supportóuntil her heart grew strong enough for
her to be taken off. "It
was truly terrible to see Lexi on ECMO," says Danielle, describing
the first time she saw the tubes coming out of her daughter's body.
"She was placed on a variety of medications to
keep her immobile and sedated while she was on ECMO, but every
other day, the nurses would ease her off of them for a short time," she
adds. "We would ask Lexi to squeeze
our hand or to give us a smile to make sure she was doing okay. That's really
what got us through. The whole time I just kept waiting for her to sit up
and tell us she was fine."
While Lexi's heart recovered enough for her to be taken off ECMO,
it was unable to heal completely. So on July 31, 2004ó25 days after
coming off the supportóLexi
underwent a heart transplant. She was released from Children's
just six weeks later, and today, the 5-year-old is thriving in
her Lockport, N.Y. home. "She's
riding her bike and getting ready to go back to kindergarten in
a few weeks. She's really doing great," said Danielle, who travels
the eight hours to Children's
every other week so Lexi can undergo biopsies to monitor her new
heart. "ECMO
was truly a miracle. I know Lexi would not be here today without
it. It saved her life."
A look ahead
New, less invasive technologies have
come alongósuch as the oscillating
ventilator, which rapidly delivers small puffs of air to oxygenate
the blood, and nitric oxide, which opens blood vessels in the lungs
and improves heart function. So ECMO has become a safety net of
sorts.
"Always having ECMO to fall back on has allowed these new technologies to evolve
very quickly. You can learn without harming the patient," says
Wilson. "Without
ECMO, these better technologiesówhich have been enormously helpfulóprobably
would never have gotten off the ground.
"I think there may always be some role for ECMO, but what that role is has yet
to be determined," he adds. "It could one day become a technology
in search of a condition to treat. But regardless, it has a rich
legacy of saving lives."
