Fundamentals of Nursing: Oxygenation - Maintaining
Respiratory Function
This resource provides a comprehensive overview of the principles underlying
oxygenation, its regulation, factors affecting it, and nursing interventions to
support optimal respiratory function.
1. Respiration: The physiological process encompassing the exchange of
oxygen (O₂) and carbon dioxide (CO₂) at the cellular level during
metabolism.
2. Three Steps of Oxygenation: The process of oxygenation involves three
interconnected steps:
1. Ventilation
2. Perfusion
3. Diffusion
3. (1) Ventilation: The mechanical process of moving gases (air) into and
out of the lungs. This allows for the renewal of air in the alveoli.
4. The Major inspiratory muscle of respiration is the Diaphragm. This dome-
shaped muscle contracts and flattens during inhalation, increasing the
thoracic cavity volume.
5. (2) Perfusion: The capability of the cardiovascular system to pump
oxygenated blood to the tissues and return deoxygenated blood to the
lungs. Effective perfusion ensures oxygen delivery and carbon dioxide
removal at the cellular level.
6. (3) Diffusion: The passive movement of respiratory gases (O₂ and CO₂)
across the alveolar-capillary membrane in the lungs and across the
, capillary-cellular membrane in the tissues, driven by concentration
gradients.
7. Work of Breathing (WOB): The effort or energy required to expand and
contract the lungs during ventilation. Increased WOB can lead to fatigue
and respiratory distress.
8. The amount of energy expended on breathing depends on three key factors:
o Rate and depth of breathing: Increased rate or depth requires more
muscular effort.
o Lung compliance: The ease with which the lungs can be expanded.
Lower compliance (stiffer lungs) increases WOB.
o Airway resistance: The opposition to airflow in the respiratory
passages. Narrowed airways increase WOB.
9. Inspiration: An active process stimulated by chemical receptors in the
aorta and carotid arteries that detect changes in blood gas levels,
triggering the contraction of inspiratory muscles.
10.Expiration: A passive process at rest that relies on the elastic recoil
properties of the lungs and thorax, requiring little or no muscle work. The
lungs naturally return to their resting volume, expelling air.
11.Surfactant: A chemical produced in the lungs by Type II alveolar cells
that reduces the surface tension of the alveoli, preventing them from
collapsing at the end of expiration and facilitating lung expansion.
12.Patients with advanced Chronic Obstructive Pulmonary Disease (COPD)
lose the elastic recoil of the lungs and thorax, making expiration an active
and energy-consuming process.
13.Atelectasis: The collapse of alveoli, preventing normal gas exchange
(oxygen and carbon dioxide) and reducing lung volume.
, 14.Compliance (Pulmonary): The ability of the lungs to distend or expand
in response to an increase in intra-alveolar pressure. High compliance
indicates ease of lung expansion, while low compliance indicates stiffness.
15.Airway Resistance: The increase in pressure that occurs as the diameter
of the airways decreases from the mouth/nose to the alveoli. Narrowed
airways (e.g., due to bronchospasm or mucus) increase resistance to airflow.
16.Tidal Volume (TV): The amount of air inhaled or exhaled with each
normal breath during quiet breathing (typically around 500 mL in adults).
17.Residual Volume (RV): The amount of air remaining in the alveoli after
a maximal (full) expiration. This air cannot be exhaled.
18.Forced Vital Capacity (FVC): The maximum amount of air that can be
forcefully exhaled from the lungs after a maximal inhalation. It is a key
measure in pulmonary function tests.
19.Pulmonary Circulation: The portion of the circulatory system that moves
blood to and from the alveolar-capillary membrane in the lungs
specifically for gas exchange.
20.Deoxygenation: The reduction of oxygen saturation in hemoglobin,
indicating that hemoglobin is carrying less oxygen.
21.Neural and Chemical regulators control the process of respiration,
ensuring adequate oxygen supply and carbon dioxide removal.
22.Cardiopulmonary Physiology involves the delivery of deoxygenated
blood (high in CO₂ and low in O₂) to the right side of the heart, which
then pumps it to the lungs for oxygenation. Oxygenated blood (high in O₂
and low in CO₂) returns to the left side of the heart to be pumped to the
systemic circulation.
Respiratory Function
This resource provides a comprehensive overview of the principles underlying
oxygenation, its regulation, factors affecting it, and nursing interventions to
support optimal respiratory function.
1. Respiration: The physiological process encompassing the exchange of
oxygen (O₂) and carbon dioxide (CO₂) at the cellular level during
metabolism.
2. Three Steps of Oxygenation: The process of oxygenation involves three
interconnected steps:
1. Ventilation
2. Perfusion
3. Diffusion
3. (1) Ventilation: The mechanical process of moving gases (air) into and
out of the lungs. This allows for the renewal of air in the alveoli.
4. The Major inspiratory muscle of respiration is the Diaphragm. This dome-
shaped muscle contracts and flattens during inhalation, increasing the
thoracic cavity volume.
5. (2) Perfusion: The capability of the cardiovascular system to pump
oxygenated blood to the tissues and return deoxygenated blood to the
lungs. Effective perfusion ensures oxygen delivery and carbon dioxide
removal at the cellular level.
6. (3) Diffusion: The passive movement of respiratory gases (O₂ and CO₂)
across the alveolar-capillary membrane in the lungs and across the
, capillary-cellular membrane in the tissues, driven by concentration
gradients.
7. Work of Breathing (WOB): The effort or energy required to expand and
contract the lungs during ventilation. Increased WOB can lead to fatigue
and respiratory distress.
8. The amount of energy expended on breathing depends on three key factors:
o Rate and depth of breathing: Increased rate or depth requires more
muscular effort.
o Lung compliance: The ease with which the lungs can be expanded.
Lower compliance (stiffer lungs) increases WOB.
o Airway resistance: The opposition to airflow in the respiratory
passages. Narrowed airways increase WOB.
9. Inspiration: An active process stimulated by chemical receptors in the
aorta and carotid arteries that detect changes in blood gas levels,
triggering the contraction of inspiratory muscles.
10.Expiration: A passive process at rest that relies on the elastic recoil
properties of the lungs and thorax, requiring little or no muscle work. The
lungs naturally return to their resting volume, expelling air.
11.Surfactant: A chemical produced in the lungs by Type II alveolar cells
that reduces the surface tension of the alveoli, preventing them from
collapsing at the end of expiration and facilitating lung expansion.
12.Patients with advanced Chronic Obstructive Pulmonary Disease (COPD)
lose the elastic recoil of the lungs and thorax, making expiration an active
and energy-consuming process.
13.Atelectasis: The collapse of alveoli, preventing normal gas exchange
(oxygen and carbon dioxide) and reducing lung volume.
, 14.Compliance (Pulmonary): The ability of the lungs to distend or expand
in response to an increase in intra-alveolar pressure. High compliance
indicates ease of lung expansion, while low compliance indicates stiffness.
15.Airway Resistance: The increase in pressure that occurs as the diameter
of the airways decreases from the mouth/nose to the alveoli. Narrowed
airways (e.g., due to bronchospasm or mucus) increase resistance to airflow.
16.Tidal Volume (TV): The amount of air inhaled or exhaled with each
normal breath during quiet breathing (typically around 500 mL in adults).
17.Residual Volume (RV): The amount of air remaining in the alveoli after
a maximal (full) expiration. This air cannot be exhaled.
18.Forced Vital Capacity (FVC): The maximum amount of air that can be
forcefully exhaled from the lungs after a maximal inhalation. It is a key
measure in pulmonary function tests.
19.Pulmonary Circulation: The portion of the circulatory system that moves
blood to and from the alveolar-capillary membrane in the lungs
specifically for gas exchange.
20.Deoxygenation: The reduction of oxygen saturation in hemoglobin,
indicating that hemoglobin is carrying less oxygen.
21.Neural and Chemical regulators control the process of respiration,
ensuring adequate oxygen supply and carbon dioxide removal.
22.Cardiopulmonary Physiology involves the delivery of deoxygenated
blood (high in CO₂ and low in O₂) to the right side of the heart, which
then pumps it to the lungs for oxygenation. Oxygenated blood (high in O₂
and low in CO₂) returns to the left side of the heart to be pumped to the
systemic circulation.
