Oxygen delivery devices

Hypoxia kills. Oxygen points can usually deliver up to 15 L/min of oxygen. Oxygen delivery depends on many variables including mask type, patient respiratory rate and minute volume. Just increasing flow does not always mean high FiO2. The concentration of oxygen the patient breathes in is determined by the type of mask as well as the flow from the wall and the breathing pattern. By using a fixed performance system (Venturi) you can gauge the percentage much more accurately

Indications for use

• Correcting hypoxaemia, Pneumothorax (helps resorb air)
• Acute myocardial infarction, Severe trauma
• Post anaesthesia recovery
• Acute severe asthma, Acute pulmonary oedema
• Acute respiratory distress syndrome
• Acute sicking crisis if hypoxic
• Cluster headaches, Carbon monoxide poisoning

Precautions and or possible complications: (Support saturations with least FiO2)

• May depress ventilation in some patients with chronic hypercapnia (CO2 retainers)
• May cause atelectasis (60% 0₂) in partially obstructed patient with use
• Oxygen toxicity (> 50% 0₂ < 24-48 hours
• In premature infants, can cause Retinopathy of Prematurity (ROP)

FiO₂ of a delivery system can vary with

• Patient's respiratory rate, effort and pattern
• Flow of gas from the equipment
• Equipment reservoir

Adjusting Oxygen therapy

• The clinical state of the patient will determine how much oxygen to give, but the acutely ill should receive at least 60% oxygen initially.
• ABG should always be checked early to assess oxygenation, ventilation (PaCO₂ ) and metabolic state (HCO₃ and base deficit).
• Always record the FiO₂ (oxygen concentration).
• Oxygen therapy should be adjusted in the light of ABGs: O₂ requirements may increase or decrease as time passes.
• High concentration oxygen is best given using a mask with a reservoir bag and at 15l can provide nearly 90% oxygen.

Mode	About	Use	Image
Room Air	Atmospheric air contains 21% oxygen. Even a modest increase can improve tissue oxygenation	Those with out additional oxygen requirement and SaO2 > 94% or those with hypercapnia and COPD
Nasal Cannula [Delivers FiO2 24-44%]	A nasal cannula (NC) comprises a thin tube with two small nozzles that protrude into the patient's nostrils. It can only comfortably provide oxygen at low flow rates. Low flow delivery system. Flow rate: 1 - 6 L/min. FiO2 starts at 24% for 1L/min and increases 4% for each L/min up to 44% for 6 L/min. Usually Well tolerated - some find this preferable to a face mask. No dead space. Must be low flow as rate: > 6 L/min cause nasal mucosal drying and nose bleeds. Use: minimal or no respiratory distress or oxygenation problem	Mild hypoxia and stable. O2 sats stable and above 90% and otherwise normal observations
Simple (Hudson) Face Mask [Delivers FiO2 24-44%]	Low flow delivery system. Small space. Use at 5-8 l/min. Must flow at over 5L/min to flush away expired CO2. Flow rate determines FiO2: 5 - 6 is 40%, 6 - 7 is 50%, 7 - 8 is 60%. Mask doesn't need tight seal. Use as one would with nasal prongs but requires higher concentrations	Same as nasal cannulae. May be preferred for comfort
Venturi Mask	High flow delivery system with flow rate b/w 4 - 12 L/min. FiO2 can be set specifically with different flow rate and air ports. Fi02 can be 24, 28, 31, 35, and 40%. External ports must remain open to entrain room air. Use in COPD patients that require specific oxygen concentrations to administer high Fi02 but not too high such that the hypoxic drive to breath is blunted; titrate to keep sats about 88-92%	Used to give precise FiO2 so may be useful with COPD and CO2 retention and need to give 24 or 28% oxygen. Colour codes BLUE = 2-4L/min = 24% O2 WHITE = 4-6L/min = 28% O2 YELLOW = 8-10L/min = 35% O2 RED = 10-12L/min = 40% O2 GREEN = 12-15L/min = 60% O2
Non-Rebreather with Reservoir Bag	High flow delivery system giving high FiO2. This mask utilizes 3 one-way valves and an oxygen bag reservoir. Supplies the highest possible oxygen concentration of any of the masks. Flow rate 6 - 15 L/min supplies 50-70% Fi02. Requires tight-fitting mask Flow can set to meet the patient's maximum inspiratory needs. The bag should not completely deflate on inspiration. Should be used when over 50% oxygen required. Use in any spontaneously breathing patient who requires the highest FiO2. Indications - carbon monoxide poisoning, trauma, severe asthma, pulmonary oedema, acute PE etc	Sick patients severe Asthma, LVF, Shock, Anaphylaxis, Acute PE, Acute pneumonia
CPAP/NIV	Positive pressure throughout respiratory cycle Prevents collapse of airways recruiting more alveoli for gas exchange and reduces the work of breathing. Can be accompanied by high FIO2. Starting pressure is 5 cm H2O. See topic	Type 1/2 Respiratory failure. NIV used for COPD. CPAP for Pulmonary oedema