Chapter 9. Critical Care

O2 via nasal cannula (provides roughly 25%–40% oxygen)*

(Use humidification system)

For non–life-threatening conditions, hypoxemia (asthma, pneumonia, bronchiolitis)

100% oxygen†, typically no more than 4 L/min flow

Well tolerated, easy to use, readily available, no associated toxicity

Skin irritation from cannula, drying of nasal passages, nose bleeds

O2 via simple face mask (provides roughly 35%–50% oxygen)*

For non–life-threatening conditions, hypoxemia (asthma, pneumonia, bronchiolitis)

100% oxygen†at no less than 5 L/min, typically 5–15 L/min

Well tolerated, easy to use, readily available, no associated toxicity, provides more oxygen than nasal cannula

If flow is <5 L/min, “rebreathing” CO2 may occur

O2 via Venturi™ mask (provides 24%–50% oxygen incrementally)

Weaning oxygen from high flow rates

The flow of 100% oxygen through the Venturi mask draws in a controlled, adjustable amount of room air (21% oxygen)

Well tolerated, easy to use, no associated toxicity, fixed and accurate concentration of oxygen

Not readily available

O2 via partial rebreathing face mask (provides roughly 50%–100% oxygen)*

For non–life-threatening conditions, severe hypoxemia (asthma, pneumonia, bronchiolitis)

100% oxygen, 5–15 L/min

Maintain reservoir at least half full on inspiration

High-flow system readily available, provides more oxygen than simple face mask

Nitrogen washout may lead to atelectasis

O2 via nonrebreather facemask (provides ∼80%–100% oxygen)*

Severe hypoxemia, hemodynamically stable pneumothorax (nitrogen washout)

100% oxygen 10–15 L/min

Maintain reservoir at least 2/3 full on inspiration and allow partial collapse on exhalation

Well tolerated, easy to use, readily ...