Modes of Oxygen Delivery

Modes of Oxygen Delivery – Blake Funke

Simple Delivery Systems

System

L/min

% O2

Indications

Comments

Blow by

 

21-100%

Trach collar

 

Nasal cannula

1-8

25 – 45%

Hypoxemia

 

Large bore nasal cannula

Up to 15

Up to 65%

Hypoxemia

Can be identified by larger bore tubing (often green) and nose piece.  Colloquially referred to as HFNC, but true HFNC = optiflow

Venturi mask

4 to 15

24 – 50%

 

Actual FiO2 is dependent on pt effort

Non-rebreather

10 to 15

65-95%

Severe hypoxemia

Often used as a bridge to higher level of O2 therapy

HFNC: Optiflow, AirVo, Vapotherm

Up to 60

30-100%

Severe hypoxemia

Delivers 0.5-1 cm/H2O of PEEP per 10L of flow

**Use of all of the above modes of O2 requires a spontaneously breathing pt

Non-invasive positive pressure ventilation:

  • CPAP
    • Indications: obstructive sleep apnea, tracheomalacia
    • Settings: CPAP, FiO2
  • BiPAP
    • Indications: hypercapnic respiratory failure (RF), hypoxic RF, pulmonary edema, obstructive sleep apnea, obesity hypoventilation syndrome, RF 2/2 neuromuscular disease
    • Settings: IPAP, EPAP, FiO2, RR (sometimes)

 

Invasive positive-pressure ventilation

Mode

You set

Not set

Comments

Pressure support (PS)

PEEP

PS above PEEP

FiO2

TV

RR

Inspiratory flow

Similar to Bipap. Frequently used for vent weaning / SBT.  Requires spontaneously breathing pt.

Volume Control (AC/VC)

PEEP

RR

TV

Inspiratory flow

FiO2

Inspiratory pressure

Mandates a minute ventilation; limits volutrauma (i.e. can guarantee LTVV)

**Primary mode used in MICU (mode used in major ARDS trials)

SIMV

PEEP

RR

TV

PS above PEEP

FiO2

 

Pt gets VC breath for set rate, but if tries to breath over this will get PS breath; VC and PS breaths are synchronized when able

Pressure Control (AC/PC)

RR

Inspiratory Pressure

PEEP

Inspiratory Time (or I:E ratio)

FiO2

TV

Minimizes barotrauma (i.e. sets a max inspiratory pressure) does not guarantee a specific minute ventilation (must monitor PCO2 with blood gases)

Does not have natural ventilator alarms for protection – need to increase low minute ventilation alarm threshold

PRVC

PEEP

RR

TV

Inspiratory flow

Pressure max

FiO2

 

Adaptive pressure control (NOT actually a volume control mode); tries to limit both barotrauma and volutrauma but if in conflict, minute ventilation will drop (i.e. need to monitor PCO2 with blood gases like any other PC mode)

Con: More the pt works, the less the ventilator does

APRV / Bilevel

PEEP (PLow)

Pressure High

Time Low

Time High

FiO2

TV

Long periods of inspiratory holds and very brief expirations (i.e. releases)

Often difficult to ventilate pts on this mode