Oxygen Delivery Flashcards
What is FiO2
Fraction of Oxygen in inhaled gas. This value is increased in patients struggling to breathe in order to deliver oxygen-enriched air (higher than atmospheric)
“Fraction of oxygen inspired above normal atomospheric level (20%) increased by 4% for every additional liter of oxygen flow administered”
Normal: 20% or 0.20 FiO2
What ratio is used to determine % FiO2 based on supplemental oxygen delivery?
4:1 – For every 1 L of oxygen, normal Fi02 (20%) is increased by 4
Low-Flow Oxygen Systems
Nasal cannula
Simple Mask
Non-rebreather
Partial non-rebreather
*Variable FiO2 levels depending on oxygen delivery and patient’s needs
High-Flow Oxygen Systems
Venturi Mask
Aerosol/Large Volume Nebulizer
*Devices meet or exceed patient’s minute volume or inspiratory demands by delivering fixed concentrations of oxygen regardless of inspiratory flow/breathing pattern
Nasal Cannula
1-6 L (FiO2 20%-44%)
Effective for low oxygen concentrations & patient with adequate TV & vital signs
Cannot deliver higher concentrations due to max of 5-6 LPM. Can dry out mucous membranes
When should the oxygen be humidified?
> 4 LMP
Simple Mask
6-10 L (FiO2 25-60%)
Used for severe asthma, pneumonia, trauma or severe sepsis. Impractical long-term.
How much oxygen is needed to flush expired carbon dioxide & prevent rebreathing of CO2?
6 LMP
Non-Rebreather
10-15 L (FiO2 80-95% … mathematically 60-80%)
HIGHEST possible oxygen concentration without intubation! Useful for extremely low levels due to quick administration (mask and reservoir)
Impractical long-term
Partial Non-Rebreather
8-12 L (FiO2 35-60%… mathematically 52-68%)
Two-way valve allowing some expired air (CO2) back into reservoir bag, diluting it and reducing its ability to administer high oxygen concentrations.
Impractical long-term
Venturi Mask
COPD patients (FiO2 24-60%)
Mixes specific volumes of air and oxygen, so liters of oxygen vary. Color of venturi device determines FiO2 (6 options)
Aerosol/Large Volume Nebulizer
10-15 L (FiO2 28-100%)
Indicated for thick secretions. Provides large volumes of mist through wide corrugated tube connected to jet nebulizer
Artificial Airway Types
Oral Pharyngeal, Nasal Pharyngeal, Tracheostomy, & Endotracheal tube (oral & nasal)
Indications for Endotracheal Tube (4)
- Upper airway obstruction
- Inability to protect lower airway from aspiration
- Inability to clear secretions
- Need for positive pressure mech ventilation
Ventilator Parameters (7)
Mode, FiO2, PEEP, RR, TV, Minute Volume, & Alarm
Which Ventilation Mode?
NON-WEANING mode that allows pt to generate as many breaths as needed by triggering the ventilator - Each spontaneous effort stimulates the machine to deliver preset tidal volume. Rate & tidal volume are set to deliver a minimum minute ventilation
Assist Control
Which Ventilation Mode?
WEANING mode that allows the patient to breathe spontaneously between ventilator breaths. Each breath will receive a VT dependent on patient’s effort. Rate and tidal volume are set to deliver minimum minute ventilation.
Good for respiratory muscle exercise! But… it increases the work of breathing for the patient.
Synchronized intermittent mandatory ventilation (SIMV)
Which Ventilation Mode?
SPONTANEOUS + WEANING mode that maintains a positive pressure within the airways continuously. Pressure support is added to augment the patient’s tidal volume.
Continuous positive airway pressure (CPAP)
Positive pressure applied at the END OF EXPIRATION during ventilation to ensure alveoli do NOT collapse
Positive end-expiratory pressure (PEEP)
Which Ventilation Mode?
SPONTANEOUS mode that only applies ventilation during spontaneous breaths. Can be combined with SIMV or CPAP. When patient triggers ventilator, preset positive pressure is delivered - Pt has FULL CONTROL of respiratory rate and inspiratory time.
Decreases work of breathing & increases comfort! But… no guaranteed ventilation
Pressure support ventilation (PSV)
