Respiration: Mechanisms and Regulation

• Respiration's mechanisms involve supplying oxygen for energy, removing carbon dioxide, maintaining acid-base balance, and regulating heat exchange.
• The respiratory center in the brainstem (pons and medulla) involuntarily controls respirations.
• Humoral regulation, specifically changes in carbon dioxide and oxygen levels, is the primary feedback loop.
• Respiration maintains blood pH or the acid-base balance.
• Hypoventilation causes CO2 buildup, leading to acidosis.
• Hyperventilation results in CO2 being blown off, causing alkalosis.
• Hypercapnia, or increased carbon dioxide in the blood, is the normal stimulus to breathe.
• Hypoxemia, low blood oxygen, increases respirations but is less effective than hypercapnia.
• Infants have adequate surfactant, a complex lipid needed for sustained air sac inflation.
• The nursing priority for infants is to clear secretions after the first breath and keep them warm.
• Nasal flaring and retractions in infants are emergent signs.
• Pregnant women experience a 50% wider thoracic cage and deeper respirations with a 40% increase in tidal volume.
• The diaphragm is pushed up by the enlarging uterus during pregnancy.

Sputum Characteristics:

• Streaks of blood in sputum indicate hemoptysis.
• Clear white sputum suggests colds and bronchitis.
• Yellow or green sputum indicates bacterial infections.
• Rust-colored sputum may indicate TB or pneumococcal pneumonia.
• Pink, frothy sputum is associated with pulmonary edema; some medications have a side effect of pink mucus.

Normal Breath Sounds:

• Bronchial sounds are normal.
• Bronchovesicular (Tracheal) sounds are normal.
• Vesicular sounds are normal.

Adventitious Sounds:

• Crackles (or rales) may disappear after the patient coughs.
• Wheezing (rhonchi) is heard with a narrowed airway, as in asthmatic patients.
• Stridor is a high-pitched inspiratory sound without a stethoscope, indicating upper airway obstruction.
• Crepitus sounds like Rice Krispies and indicates air trapped in lung tissue (subcutaneous emphysema).
• Asthma involves airflow obstruction and airway inflammation, resulting in wheezing.
• Pneumothorax alters breathing patterns.
• Hypoventilation is an irregular shallow pattern caused by narcotics or anesthetics.
• Bradypnea is slow breathing with a decreased, regular rate of fewer than 10 breaths per minute.
• Cheyne-Stokes breathing ranges from very deep to very shallow with periods of apnea.
• Tachypnea is rapid, shallow breathing with more than 24 breaths per minute.
• Biot respiration is similar to Cheyne-Stokes but with an irregular pattern.
• Chronic Obstructive Breathing involves normal inspiration and prolonged expiration to overcome airway resistance.
• A silent chest, meaning no air movement, is an ominous sign.

COPD:

• May cause barrel chest, which increases the anteroposterior diameter of the chest.
• May cause tripod positioning.
• Symmetric chest expansion involves placing warmed hands on the posterolateral chest wall with thumbs at the T9 or T10 level.
• Unequal chest expansion occurs with atelectasis, lobar pneumonia, pleural effusion, or thoracic trauma.
• Skin color should not be cyanotic or pale.

Tactile (or vocal) fremitus

• Symmetry is vital is vital; vibrations should feel the same on each side.
• Decreased fremitus indicates obstruction (pleural effusion or thickening, pneumothorax, or emphysema).
• Increased lung tissue density improves sound vibration conduction and increases tactile fremitus.
• Increased fremitus can occur with compression or consolidation of lung tissue (lobar pneumonia).
• Thoracic expansion decreases with age, making the thorax less mobile.
• Respiratory muscle strength begins to decline after age 50 and continues into the 70s.
• The aging lung has less tendency to collapse and recoil due to decreased elasticity, which makes it more rigid.
• Increased respiratory rate and a shallower inspiratory phase are expected in aging adults.
• Fewer alveoli result in a reduced area for gas exchange, increasing the risk of dyspnea with exertion.
• Atelectasis refers to collapsed, poorly aerated alveoli that deflate and accumulate secretions.
• Tuberculosis (TB) is an airborne lung disease that has infected one-third of the population.
• Nursing intervention for respiratory congestion involves fluids to aid sputum excretion, if not contraindicated.

Post-surgery complications include:

• Fat embolism.
• Pulmonary embolism.
• Atelectasis can be addressed with breathing exercises, coughing, and splinting.
• Cerebral hypoxia mental status changes which may be reflected by excessive drowsiness or anxiety, restlessness, and irritability.
• Sudden Infant Death Syndrome (SIDS) risk is reduced by having the child sleep on their back.
• Increased risk of SIDS with parents who smoke.
• Bronchodilators like albuterol are used to treat asthma by opening airways.
• Laryngeal cancer, often caused by tobacco and alcohol exposure, manifests as persistent hoarseness.
• Clubbing of the nails is caused by extended chronic hypoxia.
• Pursed-lip breathing increases airway pressure during exhalation, reducing trapped air in COPD patients.
• Suspect pulmonary edema in patients with dyspnea and pink, frothy sputum.