Oxygen Delivery Flashcards
What is FiO2?
The fraction of oxygen within inhaled air
-natural air includes 20% oxygen: FiO2 = 0.20
-medical patients are provided with oxygen-enriched air, which is higher than atmospheric FiO2
**accurate FiO2 can not be delivered with nasal canula
What are examples of low-flow oxygen systems?
-nasal canula
-simple mask
-non-rebreather
-partial non-rebreather
**varies depending on the delivery device and the patient’s oxygenation needs
What are examples of high-flow oxygen systems?
-venturi mask
-aerosol/large volume nebulizer
-ventilators
**deliver fixed concentrations of oxygen, regardless of the inspiratory flow or breathing pattern
What is the FiO2 range through a nasal canula
24-44% (1-6 L) - the fraction of oxygen inspired increases by 4% for every additional liter of oxygen flow administered
-Example: 1 L= 24%, 3 L= 32%
T/F a nasal canula is able to deliver both low and high concentrations of O2
False- cannot deliver high concentrations, only effective for low concentrations
Considerations for nasal canula
-can dry out mucous membranes
-the maximum flow if 5-6 LPM (change devices if patient requires >5 LPM)
-use on patients with adequate tidal volume and normals vitals
What is the FiO2 range for a simple mask?
25-60% (6-10 L)
Considerations for a simple mask
-tight seal is required for higher oxygen concentrations
-hot and confining
-impractical long-term use
**a minimum of 6 LPM is required for all masks to flush expired CO2 to prevent rebreathing of it
which conditions are simple masks used for?
-severe asthma
-pneumonia
-trauma
-severe sepsis
What is the fiO2 range fir a non-breather?
80-95% (10-15 L)- delivers the highest possible oxygen concentrations without incubation
Considerations for a non-breather
-used when pts have low blood oxygen levels
-used for short-term therapy
-requires a tight seal
-consists of a mask and a reservoir
what is the FiO2 range for a partial non-rebreather
35-60% (8-12 L)
Considerations for a partial non-rebreather
-looks similar to a non-rebreather mask but it contains a 2-way valve between mask and the reservoir bag
-valves allow expired CO2 to leave the mask
-cannot obtain as high of a blood oxygen concentration since the O2 in the reservoir bag becomes diluted
range of FiO2 for venturi mask
24-60% - determined by the color of the venturi device
**an accurate O2 concentration depends on oxygen liter flow and the color of the attached venture device
which patients use a venturi mask?
COPD patients
range of FiO2 for an aerosol/large volume nebulizer
28-100% (10-15 L)
Considerations for an aerosol/large volume nebulizer
-administers large volumes of mist
-indicated for thick secretions
-observe for signs of over-hydration, pulmonary edema, crackles
what is an oral pharyngeal airway?
a semirigid tube of plastic or rubber shaped to fit the natural curve of the soft palate and tongue
What is a nasal pharyngeal airway?
a soft or rubber tube inserted through one of the nares- follows the wall of the nasopharynx and oropharynx to the base of the tongue
**less likely to stimulate gag reflex
What is an endotracheal tube? && what are the different types?
artificial airway inserted into the trachea
-oral endotracheal tube: inserted via the mouth
-nasal endotracheal tube: inserted via the nose
What are the 4 reasons to use endotracheal intubation?
- upper airway obstruction
- inability to protect the lower airway from aspiration
- inability to clear secretions from the lower airways
- need for positive pressure mechanical ventilation
What is a trachestomy?
an airway opening that is surgically created directly over the trachea and inserted below the level of the vocal cords
what are the modes of ventilation?
-assist control
-synchronized intermittent mandatory ventilation (SIMV)
-continuous positive airway pressure (CPAP)
-positive end-expiratory pressure (PEEP)
-pressure support ventilation (PSV)
What is assist control?
a non-weaning mode where the rate and tidal volume are set to deliver a minimum minute ventilation
-pt can generate as many breaths as needed by triggering the ventilator
-with each respiratory effort by the pt, the machine delivers the preset tidal volume
What is synchronized intermittent mandatory ventilation (SIMV)?
a weaning mode where the rate and tidal volume are set to deliver a minimum minute ventilation
-pt can breathe spontaneously between ventilator breaths
-each breath depends on the patient’s effort
-good for respiratory muscle exercise
What is the main disadvantage os SIMV?
it increases the work of breathing so if the patient shows signs of fatigue they may need to switch to another mode
What is continuous positive airway pressure (CPAP)?
A weaning and spontaneous mode of ventilation that maintains positive pressure continuously in the airways
-pressure support is added to augment patient’s tidal volume
What is positive end-expiratory pressure (PEEP)
Positive pressure that is applied at the end of expiration during ventilation
-ensures that alveoli don’t collapse
What is pressure support ventilation (PSV)?
Once the patient triggers the ventilator, a preset positive pressure is delivered
-applies to spontaneous breaths only and the patient controls the respiratory rate and inspiratory time
-it helps to decrease the work of breathing and allows for more patient comfort
What is the disadvantage of PSV?
there is no guaranteed ventilation- if the pt stops breathing for any reason, then ventilation ceases and alarms will sound
