Controlled by the respiratory center in the lateral medulla oblongata, respiration is the exchange of oxygen and carbon dioxide between the atmosphere and body cells. External respiration, or breathing, is accomplished by the diaphragm and chest muscles and delivers oxygen to the lower respiratory tract and alveoli.
Four measures of respiration—rate, rhythm, depth, and sound—reflect the body's metabolic state, diaphragm and chest-muscle condition, and airway patency. Respiratory rate is recorded as the number of cycles (with inspiration and expiration comprising one cycle) per minute; rhythm, as the regularity of these cycles; depth, as the volume of air inhaled and exhaled with each respiration; and sound, as the audible digression from normal, effortless breathing.
Watch with second hand.
  • The best time to assess the patient's respirations is immediately after taking his pulse rate. Keep your fingertips over the radial artery, and don't tell the patient you're counting respirations. If you tell him, he'll become conscious of his respirations and the rate may change.
  • Count respirations by observing the rise and fall of the patient's chest as he breathes. Alternatively, position the patient's opposite arm across his chest and count respirations by feeling its rise and fall. Consider one rise and one fall as one respiration.
  • Count respirations for 30 seconds and multiply by 2 or count for 60 seconds if respirations are irregular to account for variations in respiratory rate and pattern.
  • As you count respirations, be alert for and record such breath sounds as stertor, stridor, wheezing, and an expiratory grunt. Stertor is a snoring sound resulting from secretions in the trachea and large bronchi. Listen for it in patients with neurologic disorders and in those who are comatose. Stridor is an inspiratory crowing sound that occurs with upper airway obstruction in laryngitis, croup, or the presence of a foreign body.
  • PEDIATRIC ALERT When listening for stridor in infants and children with croup, also observe for sternal, substernal, or intercostal retractions.
  • Wheezing is caused by partial obstruction in the smaller bronchi and bronchioles. This high-pitched, musical sound is common in patients with emphysema or asthma.

  • PEDIATRIC ALERT In infants, an expiratory grunt indicates imminent respiratory distress.
  • ELDER ALERT In older patients, an expiratory grunt may result from partial airway obstruction or neuromuscular reflex.
  • Watch the patient's chest movements and listen to his breathing to determine the rhythm and sound of respirations. (See Identifying respiratory patterns.)
  • To detect other breath sounds—such as crackles and rhonchi—or the lack of sound in the lungs, you'll need a stethoscope.

  • Observe chest movements for depth of respirations. If the patient inhales a small volume of air, record this as shallow; if he inhales a large volume, record this as deep.
  • Observe the patient for use of accessory muscles, such as the scalene, sternocleidomastoid, trapezius, and latissimus dorsi. Using these muscles reflects weakness of the diaphragm and the external intercostal muscles—the major muscles of respiration.

Special considerations
  • Respiratory rates of less than 8 or more than 40 breaths per minute are usually considered abnormal; report the sudden onset of such rates promptly. Observe the patient for signs of dyspnea, such as an anxious facial expression, flaring nostrils, a heaving chest wall, and cyanosis. To detect cyanosis, look for characteristic bluish discoloration in the nail beds or the lips, under the tongue, in the buccal mucosa, or in the conjunctiva.
  • In assessing the patient's respiratory status, consider his personal and family history. Ask whether he smokes and, if so, for how many years and how many packs per day.
  • PEDIATRIC ALERT A child's respiratory rate may double in response to exercise, illness, or emotion. Normally, the rate for neonates is 30 to 80 breaths/minute; for toddlers, 20 to 40; and for children of school age and older, 15 to 25. Children usually reach the adult rate (12 to 20) at about age 15.
Record the rate, depth, rhythm, and sound of the patient's respirations.