As a prelude to a more detailed post on high flow (coming tomorrow) I thought that it would be a good idea to brush up on standard oxygen delivery devices and techniques – you know, the ones we use every day.

Blow-by

  • Temporary O2 delivery
  • Oxygen tubing, corrugated tubing, or simple mask held at a short distance from the child’s face
  • Flow of at least 10L/min delivers <30% O2 Davies, Pediatrics, 2002
  • Self-inflating (Ambu) ventilation bags should not be used to provide blow by oxygen since small patients can’t generate enough inspiratory force the overcome the one way valve. Flow-inflating (Mapleson) bags can be used however.

Nasal cannula

  • Oxygen flowing into the nasopharynx mixes with room air
  • paO2 varies by respiratory rate, tidal volume, oxygen flow rate, and mouth breathing
  • Can give up to 100% O2 at a comfortable rate of 1 to 4 L/min
  • >2L/min is very irritating unless heated/humidified
  • The oxygen concentration that is delivered varies from 25-40% Bazuayae, Thorax 1992 
  • With flow >2 L/min you can actually generate unintended positive pressure Locke, 1992  Pediatrics
  • In preemies mean pressure up to 9.8 cm H2O at higher flow rates

Face mask

Partial rebreather

  • Simple mask with an attached reservoir
  • 50-60% O2 with flow 10-12 L/min
  • You adjust flow rate to keep reservoir from collapsing
  • Patients get O2 from inflow and the reservoir bag
  • Mostly used to conserve O2 reserves (such as in transport)

Non-rebreather

  • Mask and reservoir system modified with two valves
  • Limits mixing of exhaled gases and room air with the oxygen supply
  • O2 up to 95% 10-15 L/min with a good seal Boumphrey, 2003 Resuscitation
  • Adjust flow to prevent collapse of reservoir

Non-rebreather

 

Head hood

  • Clear, plastic cylinders that encompass the infant’s head
  • O2 80-90% percent @ flow of ≥10-15 L/min
  • Air enters through an inlet and exits through neck opening
  • Good if they can’t tolerate NC
  • Too small for babies >1 year of age

Oxygen tent

  • Clear, plastic shells that surround the child’s head and upper body
  • Up to 50% O2 w/ high flow rates
  • More RA mixing than hoods
  • Not sufficient in practice if babies need >30% O2
  • More limits to accessing the patient