In the Neonatal Intensive Care Unit (NICU), a premature baby’s heart and blood pressure is constantly monitored. A baby’s
heart is also assessed with a stethoscope.
Beyond the stethoscope, which is very useful at detecting certain heart and circulation problems, premature babies suspected
of having heart problems are likely to have other diagnostic procedures performed. These procedures can give a very detailed
picture of the function and structure of the heart. Because the heart and lungs work together to bring oxygen into the body
and distribute it through to all organs and tissues, measuring the amount of oxygen in the blood can also be an indication
of heart function.
Electrocardiogram
| Electrocardiogram |
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An electrocardiogram (ECG) is a test that records the electrical activity of the heart on a graph. The test gives the doctor
information about the heart rate, which indicates whether there is any heart rhythm abnormality, and the size of the heart
muscle.
The test takes about 10 minutes and is completely painless. Your premature baby will need to lie still on a bed for about
one minute while the recording is taken. Small stickers, called electrodes, are placed on the arms, legs, and chest and are
attached to a recording machine.
Echocardiogram
A two-dimensional echocardiogram, or 2D echo, is a test that uses sound waves to get a picture of the structure of your premature
baby’s heart. This test is painless and entirely safe. It is called Doppler echocardiography when the direction of blood flow
is assessed. A 2D echo is done to evaluate a baby’s heart when there may be a congenital heart defect or other heart condition.
During the test, the baby’s heart rate, heart rhythm, breathing, and blood pressure are carefully monitored.
| Echocardiogram |
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A technologist will first put three stickers, called electrodes, on your baby’s chest. These electrodes are attached by wires
to the echo machine. They are used to record your baby’s heartbeat during the test. Next, the technologist will put some cool
jelly on your baby’s chest. The probe, called a transducer, rests lightly on the jelly and is moved around to take pictures
of your baby’s heart from different angles. This procedure is rather like the ultrasound the mother has while the baby is
still in the womb. You can watch these pictures on a TV screen. All the pictures are recorded on a videotape or disc. Your
baby will feel a slight pressure from the probe resting on her chest. Sometimes a loud swooshing noise can be heard as the
machine records the flow of blood through the heart. A 2D echo takes from 30 minutes to one hour or more. When the echo is
completed, the jelly will be wiped off.
Oxygen saturation monitoring
What is oxygen saturation?
Oxygen saturation refers to the amount of oxygen the red blood cells (RBCs) are carrying. Under normal healthy circumstances,
RBCs that have passed through the lungs should be full of, or saturated with, oxygen. If a premature baby has a respiratory
condition that prevents the RBCs (specifically the hemoglobinin RBCs) from picking up oxygen, the oxygen saturation level
will be lower.
This reduced amount of oxygen in the blood, called hypoxemia, can be indicated by the presence of cyanosis, which is a bluish
tinge to the baby’s skin.
What is oxygen saturation monitoring?
Oxygen saturation monitoring measures the amount of oxygen in a premature baby’s blood. It helps the nurses and doctors know
if your baby’s body is getting the oxygen it needs. A long, thin wire is attached to a monitor. This wire connects to a cover
called a probe, also called a sensor. The probe is put over your baby’s finger or toe. The probe has a small red light on
one side and a detector on the other side. The red light shines through your baby’s finger or toe and is seen by the detector
on the other side. The detector measures the amount of oxygen in the blood. This way of checking oxygen is called pulse oximetry.
The monitor and the probe are completely safe. The probe will be applied securely but not tightly to your baby’s finger or
toe. This does not hurt. The nurse will probably move the probe to a different finger or toe about every eight hours. This
will help make sure that the probe is still working properly. It also gives a rest to your baby’s finger or toe.
What makes the monitor alarm go off?
Your baby’s nurse will set ranges on the monitor based on your premature baby’s age, illness, and vital signs. If your baby’s
heart rate or oxygen level go outside these ranges, an alarm will go off. If the monitor alarm goes off, a nurse will come
and check your baby.
If oxygen levels are found to be low, your premature baby will receive oxygen in concentrations higher than would be present
in the regular air we breathe. This is delivered through a face mask or tubes in the nose, called nasal cannulae, or through
a connection to a mechanical ventilator. This is known as oxygen therapy.
