Respiration
Respiration is the act of breathing; supplying oxygen to the body cells and removing carbon dioxide from the body cells. Respiration refers to two processes:
1. External respiration involves inhalation or inspiration of air into the lungs and exhalation or expirations breathing out or the movement of gases from the lungs to the atmosphere.
External respirations has three components: a.
Ventilation – mechanical movement of air in and out of the lungs b.
Diffusion – movement of oxygen and carbon dioxide between the alveoli and the red blood cells c.
Perfusion – the distribution of blood to and from the pulmonary capillaries in the lungs out to the body tissues.
2. Internal Respiration occurs at the cellular level. Oxygen diffuses from the hemoglobin in the red blood cell to the cells of the body for use in production of heat and energy, and carbon dioxide is given off from the body cell as a waste by-product of metabolism.
Control of Respirations
Breathing is automatic and involuntary, but can be influenced by a person’s voluntary control and activities.
Involuntary control of breathing is by the respiratory center in the brain stem and chemoreceptors in the carotid artery and aorta. Respirations are regulated by levels of carbon dioxide, oxygen, and hydrogen ion concentration (pH) in the arterial blood.
The most important factor in the control of respirations is the level of carbon dioxide in the arterial blood. An elevation of carbon dioxide causes the respiratory control system in the brain to increase the rate and depth of breathing. The increased ventilation removes excess carbon dioxide during exhalation.
Chemoreceptors in the carotid artery and aorta are sensitive to low levels of arterial oxygen. If arterial oxygen levels drop, these receptors signal the brain to increase the rate and depth of ventilation to bring in more oxygen.
Assessment of Respirations
Respirations are the easiest of all vital signs to assess, but are often the most haphazardly measured. A nurse must not estimate respirations.
Accurate measurements require observation and palpation of chest wall movement. Most of the time, respirations should be assessed when the patient is at rest. Before assessing a patient’s respirations, a nurse should be aware of:
 The patient’s normal breathing pattern
 The influence of the patient’s health problems on respirations
 Any medications or therapies that might affect respirations.
 The relationship of the patient’s respirations to cardiovascular function.
Assessment of a patient’s breathing pattern includes rate, rhythm, depth, and effort.

Characteristics of Respirations
Rate:
Respiratory rate is normally described in breaths per minute. The normal respiratory rate for an adult is between 12 and 20 breaths per minute. Breathing that is normal in rate and depth is called eupnea. Abnormally slow respirations are called bradypnea and abnormally fast respirations are called tachypnea.
Apnea is the cessation or absence of breathing.
Factors that influence respiratory rates include: a. Exercise – increases the rate b. Stress – increases the rate c. Increased altitude - increases the rate d. Medications (narcotics and analgesics) – decrease the rate
Rhythm:
Respiratory rhythm refers to the regularity of the expirations and inspirations.
Normally, respirations are evenly spaced in an adult. Irregular respirations are normal in an infants and children. Irregular respirations in an adult indicate complications and should be reported.
Depth:
Respiratory depth is assessed by observing the degree of movement in the chest wall. Depth is generally described as normal, deep, or shallow. Deep respirations are those in which a large volume of air is inhaled and exhaled, with full expansion of the lungs. Shallow respirations involve the exchange of a small volume of air and often the minimal use of lung tissue. During a normal inspiration and expiration or the volume of air exchanged with each breath in an adult is about 500 ml. of air. This volume is called the tidal volume.
Effort:
Normal respiratory ventilation is effortless. To determine the amount of effort used to breathe, the nurse should assess the chest – does it expand symmetrically with inspiration, is there retraction of the intercostals spaces between the ribs on inspiration, are the respirations diaphragmatic or costal, are accessory muscles used to augment respiratory effort. Difficult or labored breathing in which the patient verbalizes a feeling of air hunger, of not getting enough air is known as dyspnea.
Sound:
Respirations should be quiet. Normal relaxed breathing produces no noise.
Noisy breathing usually indicates some obstructed breathing. An example of abnormal breathing sounds include: a. Stridor – shrill, harsh, inspiratory crowing sound that occurs with upper airway obstruction as in laryngitis or croup. b. Wheeze – high-pitched , musical, whistling sound that occurs with partial obstruction in the smaller bronchi and in emphysema or asthma. c. Stertor – snoring respiration produced by secretions in the trachea and large bronchi.
To more accurately assess the lungs and respirations, the nurse can auscultate the lungs with a stethoscope. Normal breath sounds are soft rustling sounds. With atelectasis or obstruction, breath sounds

Abnormal Breathing Patterns:
1. Hypoventilation – rate and depth are decreased.
2. Hyperventilation – rate and depth are increased.
3. Cheyne-Stokes – alternating periods of apnea, hypoventilation, and hyperventilation.
4. Kussmaul – rate and depth are increased.