Spontaneous Breathing Pattern
The establishment of the tidal volume and pattern of respiration in normal individuals is a complicated process. Recognizing alterations in these factors is an important early clue of disease recognition. While frequently it is nonspecific, in many instances it can lead directly to a diagnosis. Careful observation of the respiratory rate and pattern is a crucial part of the physical examination.
Simple inspection of the respiratory cycle, observing rate, rhythm, inspiratory volume, and effort of breathing, is all that is necessary. The rate is noted by observing the frequency of the inspiratory phase since this phase is active and easy to count. Record the number of breaths per minute; this is the respiratory rate. While observing the rate, note the inspiratory expansion of the chest cage. This expansion should be the same during each cycle.
Normally, the accessory muscles of inspiration and expiration are not used. Their use should be observed and, if found, recorded as “use of accessory muscles on inspiration” and “expiration is active with abdominal muscle contraction.”
- FEV 1
Forced expiratory volume in 1 s
Partial pressure of carbon dioxide inarterial blood
Partial pressure of oxygen in arterial blood
Total cycle time
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