Respiratory Monitoring Flashcards
(102 cards)
after how long of breathing with what oxygen concentration can lead to oxygen toxicity?
50% for longer than 24 hours
what should fiO2 be titrated based upon to prevent oxygen toxicity?
minimal amount possible to keep PaO2 above 60mmhg or sats above 90-92%
What is a physiological shunt? What does the ventilation perfusion ratio look like? What processes is this seen in?
Blood is passing by alveoli without gas exchange occurring, low ventilation.
There is a low ventilation to perfusion ratio, possibly zero.
pneumonia, atelectasis, tumor, mucous plug
What is alveolar dead space? What does the ventilation perfusion ratio look like? What processes is this seen in?
The alveoli arent being perfused enough to allow for adequate gas exchange.
High ventilation to perfusion ratio.
Pulmonary embolus, pulmonary infarction, cardiogenic shock, mechanical ventilation with high tidal volumes.
What is a silent unit? What does the ventilation perfusion ratio look like? Where can this be seen?
This is where the alveoli arent being ventilated or perfused.
Both ventilation and perfusion are low in the ratio in this case.
This can be seen with a pneumothorax, hemothorax, or SEVERE ARDS or severe asthma.
What is positive cooperativity in relation to hemoglobin molecules?
This is the fact that as each of the 4 heme groups receives an oxygen molecule within a hemoglobin molecule, its affinity for oxygen to bind to it increases.
At 40mmHg, how saturated are hemoglobin molecules?
They are still about 70-75% saturated. This is enough of a reserve to provide oxygen to tissues in an emergency or strenuous exercise.
What are some things that effect hemoglobins ability to bind with oxygen?
pH, carbon dioxide concentration, temperature, and 2-3 DPG (diphosphoglycerate)
What are some things that increase the affinity of hemoglobin binding to oxygen? What shift does this correlate to on the oxyhemoglobin dissociation curve?
Increase pH
Decreased CO2 (Increases pH in most instances)
Decreased body temperature
Decreased 2,3 - DPG
THIS RESULTS IN A SHIFT TO THE LEFT, HEMOGLOBIN MORE READILY BINDS TO OXYGEN, THEREFORE LESS OXYGEN IS AVAILABLE FOR THE TISSUES
What is 2,3-DPG and what is its role in effecting hemoglobins ability to bind to oxygen?
2,3-DPG is a phosphate (inorganic) that is produced by RBCs, it is also an acid. It binds to hemoglobin (specifically the beta-chain) which decreases the affinity of hemoglobin to bind to oxygen, leaving oxygen more readily available for the tissues (right shift).
What are some things that decrease the affinity of hemoglobin to bind to oxygen? What shift would this correlate to on the oxyhemoglobin dissociation curve?
Decreased pH
increaseed CO2
Increased temperature
increased 2,3-DPG
This causes a shift to the right of the oxyhemoglobin dissociation curve, which means that there is a decreased affinity for hemoglobin to bind to oxygen, causing an increased availability of oxygen tot he tissues.
What is the percentage of oxygen that is dissolved in the plasma (PaO2)? Where is the other 97% of oxygen?
3% (normal PaO2 is 80-100mmHg)
The other 97% is bound to hemoglobin (SaO2 93-99%)
What is the difference between PaO2 and SaO2? What are the normal values?
PaO2 is the pressure/amount of dissolved oxygen in the plasma (80-100 mmHg)
SaO2 is the amount of oxygen bound to hemoglobin (93-99%)
What is the normal range for ABG values? (PaO2, PaCO2, HCO3, pH)
PaO2 - 80-100 mmHg
PaCO2 - 35-45 mmHg
HCO3 - 22-26
pH - 7.35-7.45
How long does it approximately take the lungs to start to compensate for pH?
Lungs - 5-15 minutes
Kidneys - 24 hours
Can either the metabolic or respiratory system overcompensate?
NO NO NO
What does FiO2 mean?
This means the fraction f inspired oxygen, when oxygen flow-rates are slower than the patients inspiratory volume (1-10l/min)
Do you give oropharyngeal airways to any patient that is conscious?
NO NO NO
Is oral suctioning a sterile process? What type of suctioning catheter would you use? What do you do after you finish suctioning EVERY TIME? What do you do before gently removing an oropharyngeal catheter?
NO, normal a yaunker is used. Rinse the tubing with tap water after suctioning. PERFORM SUCTIONING BEFORE REMOVAL.
When would you want to use caution in using a nasopharyngeal airway?
patients with craniofacial injuries.
What is the max amount of time suctioning can be performed?
15 seconds
When is an ETT necessary?
When the patient needs to be ventilated or if the airway needs to be protected.
What ways can an ET tube be inserted?
Orally or nasally
What are the advantages to an orally inserted ETT? Any disadvantages?
Pros: Less trauma, larger tube can be used, less infections
Cons: they are uncomfortable