Ambulatory Children With Single Ventricle Clinical Trial
Official title:
Evaluation of Near-infrared Spectroscopy for Non-invasive Monitoring of the Ambulatory Single Ventricle Patient
The normal heart has four chambers. There are two upper (or filling) chambers and are called
the atrium. There are two lower (or pumping) chambers and are called the ventricles. One of
the ventricles pumps blood to the lungs to get oxygen. This oxygenated blood is returned to
the heart then pumped to the rest of the body by the other ventricle.
Sometimes babies are born with heart defects that only allow one of the lower chambers
(ventricle) to work properly. This means that the one ventricle must pump blood to both the
lungs and to the rest of the body. Babies born with this defect must undergo multiple
surgeries, the first of which is usually done during their first week of life.
There is a machine that is FDA approved that can measure how much oxygen is delivered to the
brain. This non-invasive (outside the body) machine uses Near-infrared spectroscopy (NIRS),
which is similar technology used in pulse oximetry and is routinely used to measure the
level of oxygen in blood. At Children's Healthcare of Atlanta, we typically place the NIRS
machine on the baby in the Cardiac Intensive Care Unit immediately after their first surgery
to monitor oxygen delivery to the brain. The monitor has proven to be accurate in this
situation.
We now want to know if we can use this monitor to assess oxygen delivery to the brain before
and during a routine heart catheterization prior to the child's second surgery. Once consent
is obtained, we will place a probe on the child's forehead during the pre-catheterization
visit and obtain readings for 5 minutes. The probes are about the size of a quarter and are
self-stick (they look like the kind of leads used to measure the babies heart rate [EKG]).
The machine will be disconnected for the rest of the Pre-catheterization visit, however the
probes will stay on the child's forehead. Once the child is in the catheterization suite,
the machine will be reconnected. A sheath or hollow tube is routinely placed in a blood
vessel in the child's neck or groin for the catheterization. The doctor would place a
special catheter in this sheath that measures oxygen levels in blood continuously. This
monitor would be calibrated by using the results of a blood sample that is routinely drawn
from the child's IV. During the same sampling, an additional 2cc's of blood would be
collected to measure the lactate level. The lactate level is an indicator of how well the
child is using oxygen. Once this monitor is calibrated, data will be collected for 5 minutes
to compare it with the NIRS machine. The special catheter will be removed after the 5-minute
time period, and the catheterization will proceed as usual. The NIRS probes will stay on the
child's forehead during the entire catheterization with the data documented. At the end of
the catheterization, the probes will be removed.
The study will be a prospective evaluation of all single ventricle patients as they undergo
their routine cardiac catheterization prior to second stage palliation. Upon arrival to the
pre-catheterization area, NIRS probes will be placed on the child's forehead and data along
with vital signs will be collected at initial placement, 3 minutes and at 5 minutes. The
monitor will be disconnected as the routine pre-catheterization procedures proceed.
Once the child is in the catheterization suite, the monitor will be reconnected and the
routine catheterization procedures will proceed. After the standard sheath for
catheterization is placed in the child, a routine superior vena cava saturation (COOX) will
be drawn and the NIRS reading along with routine vital signs will be documented. At the same
time the routine saturation is drawn, an additional 2ccs of blood will be drawn for a
lactate level. At 3 and 5 minutes after the routine saturation, a COOX will be drawn and the
NIRS reading along with vital signs will be documented. The catheterization will continue as
usual. At the end of the case, a final NIRS reading and vital signs will be documented prior
to the removal of the probes.
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Time Perspective: Prospective