Module 2 - Oxygenation and Vital Signs Flashcards
What is the difference between hypoxemia and hypoxia?
Hypoxemia is a condition where the partial pressure of oxygen is lower than normal ( <80 mmHg), indicating an inadequate supply of oxygen in the arterial blood.
Hypoxia involves a reduction in oxygen supply at the tissue level, rather than the partial pressure of oxygen in the arteries.
True or false? A patient who has hypoxemia will also have hypoxia
False. Hypoxia and hypoxemia often go hand in hand, but patients can compensate for low PaO2 by increasing oxygen supply - ^^ cardiac output (^ HR), lowering tissue O2 consumption
True or false? A patient who has hypoxia will also have hypoxemia?
False. If a patient has adequate partial pressure of oxygen in the arteries, but the tissues are unable to use it, or delivery to the tissues is diminished, they may be hypoxic but not hypoxemic.
What is one situation where oxygen supplementation would NOT improve hypoxia?
If the cause for the hypoxia is related to cardiac function (ie. decreased cardiac output, anemia)
What is oxygen supply?
Oxygen that we are breathing in through our lungs and traveling through the circulatory system to tissues
What is oxygen demand?
The amount of oxygen needed by cells to maintain homeostasis, driven partially by metabolic needs
What is oxygenation?
Process of taking oxygen from the environment and delivering it to cells
What is ventilation?
The process of moving air into the alveoli, involves inspiration and expiration
What is respiration?
The exchange of CO2 and O2 at the alveoli and capillaries (external) and at the capillaries and tissues (internal)
What are the 2 types of respiration?
Internal and external
What processes does oxygenation rely on?
Ventilation, external and internal respiration, circulatory system
What factors influence ventilation?
Intact thoracic cavity wall, patent airway, functioning muscles, lungs clear of debris/fluid/obstructions
What are some of the muscles of inspiration?
Main: External intercostals, diaphragm
Accessory: sternocleidomastoid, pectoralis minor
What are some of the muscles of expiration?
Main: Internal intercostals, diaphragm
Accessory: abdominals, quadratus lumborum
What happens if the thoracic cavity is no longer intact?
Will not be able to maintain negative pressure needed to move air into lungs
What types of receptors control ventilation? What area of the brain controls ventilation rate?
Chemoreceptors that monitor for PaCO2 and PaO2 and send signals to the medulla to modify RR and depth
What is PEEP and how does it help improve external respiration?
Positive end expiry pressure (such as a cough, deep breathing, pursed lip breathing). Improves external respiration by increasing the pressure difference and allowing more air to be inhaled
Which type of respiration requires lots of ventilated + intact alveoli, and capillaries close to the alveolar wall?
External respiration
Which type of respiration requires adequate flow of oxygenated blood to cells, diffusion of O2, and the presence of glucose or fatty acids?
Internal respiration
What is the role of glucose or fatty acids in internal respiration?
Primarily provide an energy source for cells to participate in gas exchange
External respiration is the exchange of gases between ______ and ______.
A) atmosphere, blood
B) skin, air
C) atmosphere, skin
D) skin, blood
A is correct
A patient is experiencing difficulty breathing due to a foreign body in the airway. This patient is experiencing difficulty with:
A) internal respiration
B) ventilation
C) external respiration
D) oxygenation
B is correct –> when there’s a foreign body in the airway, this is an issue with the process of getting air in/out of our lungs.
A patient with asthma is having an asthma attack. The patient’s alveoli are collapsing. This patient is experiencing difficulty with:
A) internal respiration
B) ventilation
C) oxygenation
D) external respiration
D is correct –> when the alveoli are involved, it’s usually external respiration.
oxygenation is technically correct as well, but the acute problem causing the issues with oxygenation are the alveoli collapsing
How do we know if pt has good kidney oxygenation?
If we aren’t seeing any issues with urination
How do we know if pt has good cardiac oxygenation?
If the skin colour is normal
How do we know if pt has good neurological oxygenation?
If patient is alert, oriented x4
What does oxygen supply depend on?
Cardiac output and arterial oxygen content
What does cardiac output depend on?
Stroke volume and heart rate