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37 Cards in this Set
- Front
- Back
What systemic effects does mechanical ventilation correct? (2) |
- Oxygenation - Ventilation |
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What terms are used for the manifestation of poor oxygenation and poor ventilation? |
Poor oxygenation = hypoxemia |
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What are the indications of mechanical ventilation? (2) |
- Patient has severe respiratory failure - A Dx or Tx procedure has risk for respiratory failure |
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In what 2 cases is mechanical ventilation used when a patient does not have severe respiratory failure, but rather is at high risk for it? |
- Stroke - AMS |
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What are the 3 types of respiratory failure? |
- Hypoxemia - Hypercarbia - Mixed form |
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On an ABG, what values suggest adequacy for oxygenation? |
Oxygenation: PaO2 & SpO2 |
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What threshold values suggest that PaO2 is adequate? |
PaO2 > 60mmHg |
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How is appropriateness of oxygen delivery assessed? |
FiO2 |
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How is FiO2 converted to PaO2? |
PaO2 = FiO2 x 5
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What does the A-a gradient tell you in terms of oxygenation? |
Whether there is poor delivery of oxygen from alveoli to arteries |
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How is A-a gradient calculated? |
Calculated alveolar pO2 minus actual pO2 |
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What is the normal A-a gradient on room air?
What about with an FiO2 of 100%? |
~10mmHg
~100mmHg |
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What are the most common causes of a widened A-a gradient? (4) |
- V/Q mismatch - Right-to-Left shunt - Increase O2 extraction - Diffusion defect (rare) |
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What are the 2 kinds of non-invasive mechanical ventilation and how do they work? |
BiPAP: puts a higher pressure during inhalation and lower PEEP during expiration CPAP: pushes air into lungs at a constant force regardless of inhalation or exhalation |
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What are two methods of invasive mechanical ventilation? |
- Endotracheal intubation - Tracheostomy intubation |
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What respiratory defect does inhalation positive airway pressure help with on the BiPAP and CPAP? |
Ventilation |
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What respiratory defect does exhalation positive airway pressure help on BiPAP? |
Oxygenation (keeping alveoli from collapsing) |
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Why should a patient with AMS not be put on BiPAP or CPAP? |
They can aspirate on their own vomitus. |
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Which noninvasive means of mechanical ventilation is high-flow nasal cannula most like? |
CPAP |
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What is the peak inspiratory pressure (PIP)? |
Highest pressure generated during inspiration |
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What is plateau pressure? On what does it depend? |
Pressure required to keep lungs distended |
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What is peak inspiratory flow? |
Greatest flow rate used to deliver Tidal Volume (Tv) during inspiration |
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What does it mean if inspiratory plateau is normal but oxygenation is decreasing? |
Airway Resistance |
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When is PEEP applied during the breathing process? What is its purpose? |
During exhalation To keep alveoli from collapsing |
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What can PEEP do to a patient that is hypovolemic? |
Hypotension |
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Which ventilatory setting is only used in the OR? |
Control Mandatory Ventilation |
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On a breathing monitor, how is patient triggered breaths differentiated from machine triggered breaths? |
Patient-triggered breaths have a brief moment of downward movement (negative pressure) before the machine kicks in. |
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What was the purpose of synchronized intermittent mechanical ventilation (SIMV) in the past? |
Waning pts off of ventilators |
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Who controls breathing on Pressure Support Ventilation? |
Patient
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What varies from breath-to-breath in Pressure Support MV? |
Tidal Volume |
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What does minute ventilation depend on in Pressure Support MV? (2) |
Tidal Volume & Respiratory Rate |
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What is a good starting FiO2? |
FiO2 = 100% |
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What dictates changes needed for MV? |
The patient's ABG |
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How soon should a physician get an ABG after starting a patient on MV for oxygenation problems? ventilation? |
oxygenation = 1hr |
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What should you adjust if PaO2 is too low for a pt on MV? (2) |
- Increase FiO2 - Increase PEEP |
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What changes in MV setting would improve hypercarbia? (2) |
- Increase RR |
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What is the catch when using high FiO2? |
It doesn't fix the underlying problem. |