Cardiopulm Unit 6 Pulmonary Anatomy/Physiology and Examination Flashcards
(105 cards)
What is Ventilation?
This refers to the delivery system that presents oxygen‐rich air to the alveoli and removes CO2 from the blood/alveoli
What are the Clinical Signs that can be use to evaluate the adequacy of ventilation at bedside?
Chest Rise and Respiratory Rate
With ventilation, what is CO2 levels affected by?
CO2 levels are mainly affected by Minute Ventilation which can be described as the amount of air that ventilated per breath (tidal volume) and the rate of breathing (TIDAL VOLUME x RESPIRATORY RATE)
What is Oxygenation?
The patient’s ability to take in oxygen from the alveoli and distribute it to the tissues and organs of the body to maintain cellular activity.
With Oxygenation,what is the difference between Hypoxia and Hypoxemia?
- Hypoxia refers to the end-result of insufficient oxygen delivery to the tissues. While not directly measurable, it is clinically suspected through different types of blood analyses and via clinical signs suggesting organ ischemia
- Hypoxemia refers specifically to low levels of oxygen in the blood. It is measured by SaO2 and SpO2. Saturation of peripheral oxygen levels measured with a pulse oximeter (SpO2) correlate highly with actual arterial oxygenation concentrations (SaO2). SaO2 tells us the percentage of hemoglobin in the blood that is fully loaded with oxygen
What is Respiration? What is Respiratory Failure?
A general term that refers to the action of breathing via the combination of ventilation and oxygenation. It is the biochemical process of both taking in oxygen and removing carbon dioxide.
- “Respiratory Failure” is a medical diagnosis that can refer to either an issue with oxygenation and/or inadequate carbon dioxide removal.
What do neurons of the brainstem (including the medulla oblongata and pons) provide?
Control for automatic breathing and adjust ventilatory rate and tidal volume for normal gas exchage
What are Chemoreceptors responsible for?
Sensing alterations in Blood pH, CO2, and O2 levels
What normal ventilation driven by?
Normal ventilation is driven mostly by the levels of carbon dioxide and less so by oxygen levels.
- Chronically high levels of CO2 (i.e., hypercapnia)
can desensitize the body to CO2 and shift respiratory
drive to rely on oxygen levels.
This pic represents the Oxyhemoglobin Dissociation Curve, what is the relationship between SaO2 and pO2?
SaO2 = Hemoglobin saturation
PaO2 = Partial Pressure of Oxygen
This is a Sigmoidal Curve
- Normally there is a drop of 5
- This means that small changes in PaO2 can lead to large changes in SaO2 at certain points on the curve
- Typically after 60 PaO2, there is a steep drop off of SaO2
What is Normal PaO2?
75-100 mmHG
When PaO2 is < 60 mmHG what does this mean?
< 60 is the standard threshold for defining the Hypoxemia seen in Respiratory Failure
What is Pleural Effusion?
This refers to an excess of pleural fluid in the pleural cavity caused by damage to pleura (e.g., by trauma, infection,
malignancy) or when there is either excessive production
of pleural fluid or the resorption capacity is reduced (e.g., lymphatic obstruction)
What can the pleural space be filled with?
- Hemothorax (blood)
- Empyema (pus)
- Air (Pneumothorax)
Is the pleural space continuous with the airways?
The pleural space is NOT continuous with the airways
With Ventilation, what are the 2 opposing forces?
- Inward pull from the elastic tension of the lung tissue trying to collapse the lung
And
- An outward pull of the thoracic wall trying to expand the lungs
With Ventilations opposing forces (Inward/outward pull), what does this give rise to?
These two opposing forces give rise to a subatmospheric
(negative) pressure within the intrapleural space, termed the intrapleural pressure.
- This intrapleural pressure is normally lower than the intrapulmonary pressure developed during both inspiration and expiration.
- In light of these two pressure differences, a transpulmonary or transmural pressure is developed across the wall of the lung
What does Transmural or Transpulmonary Pressure allow?
This allows changes in lung volume to parallel changes in thoracic excursion during inspiration and expiration
What does the Diaphragm do during contraction?
It flattens and moves downward, increasing the space in the chest cavity and decreasing the pressure inside the chest, allowing air to flow into the lungs
What does the Diaphragm do during relaxation?
On relaxation it moves upward into its dome shape, decreasing
the space in the chest cavity and increasing the pressure,
which helps to push air out of the lungs (exhalation)
What innervates the Diaphragm?
Phrenic Nerve
What can the Functioning of the Diaphragm be affected by?
- Weakness and/or fatigue (e.g., after invasive ventilatory support)
- Hyperinflation
- Paralysis or Hemi-paralysis
- Medical procedure (e.g., surgical pain
What is the Pores of Kohn?
Alveoli have direct connections with each other
- Small, natural openings in the walls between adjacent alveoli, allowing for collateral airflow and equalization of pressure between them.
What are the Channels of Lambert?
Microscopic collateral airways between the distal bronchiolar tree and adjacent alveoli.