a. Rate. A normal adult will breathe at a steady rate. A breathing rate from 12
to 20 breaths per minute is normal. Children have a normal breathing rate of 20 to 28
breaths per minute. Infants have a normal range of 30 to 60 breaths per minute.
(1) Normal. A patient's breathing rate is said to be normal if it is within the
appropriate range. For example, a breathing rate of 26 is normal for a young child, slow
for an infant, and rapid for an adult.
(2) Rapid. If a patient's breathing rate is higher than the normal range, then
his breathing is rapid. Rapid breathing is also known as hyperventilation.
(3) Slow. If a patient's breathing rate is below the normal range, his
breathing is slow.
b. Depth. The depth of ventilation refers to the amount of air that is inhaled and
exhaled. The amount of air inhaled and exhaled in one cycle is called the tidal volume.
The more the chest cavity expands, the greater the depth of the ventilation. Full
expansion of the chest wall with full relaxation on exhalation is a good indicator of
adequate depth of breathing and adequate tidal volume. Many books will try and apply
numbers in milliliters per breath to calculate tidal volume. This is not possible to
measure in the field, so it is important to asses the expansion of the chest to help
determine tidal volume.
(1) Normal. Normal depth of breathing is hard to determine. The chest will
not expand to its full capacity with each breath. If a patient is not showing signs of
distress, is alert, and has a normal skin color, then you can gauge that the breathing
depth is normal and adequate for his condition. Airflow of about 500 ml each breath is
normal in an adult.
(2) Shallow. If a patient's chest and abdomen rise and fall only slightly, the
patient's breathing is shallow. A patient with shallow breathing will probably breathe at
a rapid rate. If a patient has a pattern of rapid, shallow breathing, he is said to be "short
of breath." Rapid and shallow breathing will not get a high enough tidal volume to allow
the air to reach the lungs for good oxygenation. A pattern of slow, shallow breathing is
called "hypoventilation."
(3) Deep. A patient's breathing is deep when the chest cavity expands to
almost its full capacity. A person who is gasping for air expands his chest to its full
capacity. A breathing pattern of rapid, deep breathing is called "hyperventilation."
c. Rhythm. The rhythm includes the entire breathing (inhalation and exhalation)
cycle.
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