Skip to content
Apex Nursing

Reference — Respiratory

Oxygen Delivery Devices

Supplemental oxygen is delivered through a range of devices that differ in flow rate, FiO₂ precision, and clinical indication. Choosing the right device — and setting it correctly — is a core nursing responsibility.

Educational use only. FiO₂ ranges are approximations and vary with patient breathing pattern and flow. Always follow provider orders, institutional protocols, and assess patient response with pulse oximetry. This material supports nursing education and exam review. It is not medical advice and is not a substitute for clinical judgment, institutional policy, or medical direction. Always follow facility protocols and current provider orders.

Device Comparison at a Glance

DeviceFlow RateFiO₂ (approx.)FiO₂ Control
Nasal Cannula1–6 L/min24–44%Variable
Simple Face Mask5–10 L/min35–50%Variable
Venturi Mask4–15 L/min24–50% (set)Precise / Fixed
Partial Rebreather6–10 L/min40–70%Variable
Non-Rebreather Mask10–15 L/min60–80%+Variable / High
High-Flow Nasal CannulaUp to 60 L/min21–100%Precise / Titrated

Nasal Cannula (NC)

Flow: 1–6 L/min
FiO₂: ~4% increase per 1 L/min above 21% (so 1 L/min ≈ 24%, 6 L/min ≈ 44%)

Nursing considerations:

  • Most comfortable device; allows eating, drinking, and talking
  • Appropriate for mild hypoxia (SpO₂ 88–94% range depending on patient condition)
  • Flow above 4 L/min should use humidification to prevent mucosal drying
  • FiO₂ is imprecise — affected by mouth breathing and respiratory rate
  • Nasal prongs should sit just inside the nostrils; check skin behind ears and nares for pressure injury

Simple Face Mask

Flow: 5–10 L/min
FiO₂: 35–50%

Nursing considerations:

  • Minimum flow of 5 L/min required to flush exhaled CO₂ from the mask
  • Side vents allow room air entrainment, reducing FiO₂ precision
  • Must be removed for eating, drinking, and oral medications — switch to NC during meals if oxygenation allows
  • Assess mask fit to avoid air leaking around the edges

Venturi Mask

Flow: 4–15 L/min (adapter-specific)
FiO₂: 24%, 28%, 31%, 35%, 40%, 50% (color-coded adapters)

Nursing considerations:

  • Delivers the most precise FiO₂ — preferred when controlled O₂ is essential (COPD, type II respiratory failure)
  • Works by entraining a fixed ratio of room air through jet ports — the adapter color specifies both the FiO₂ and required flow rate
  • Particularly important in COPD patients at risk of hypercapnia — avoid overshooting FiO₂ targets (excess O₂ worsens CO₂ via V/Q mismatch, not loss of "hypoxic drive")
  • FiO₂ remains stable regardless of breathing pattern

Non-Rebreather Mask (NRB)

Flow: 10–15 L/min
FiO₂: 60–80% (can approach 100% with tight seal)

Nursing considerations:

  • Highest FiO₂ achievable without mechanical ventilation or HFNC
  • Reservoir bag must remain inflated at all times — inflate before applying
  • One-way valves prevent exhaled CO₂ from re-entering the reservoir bag
  • Used for serious hypoxia, CO poisoning, respiratory emergencies
  • If the bag deflates with inspiration, increase flow rate
  • Not appropriate for long-term use — patient should be reassessed for escalation or de-escalation of therapy

High-Flow Nasal Cannula (HFNC)

Flow: Up to 60 L/min
FiO₂: 21–100% (precisely titrated)

Nursing considerations:

  • Delivers heated and humidified oxygen — reduces mucosal drying and improves tolerance at high flows
  • High flow provides a small degree of PEEP (~1 cmH₂O per 10 L/min) and flushes nasopharyngeal dead space
  • FiO₂ and flow are set independently — allows precise titration
  • Used in acute hypoxic respiratory failure, post-extubation, high-risk procedures
  • Requires specialized equipment (Optiflow or equivalent heated humidifier system)
  • Monitor closely — HFNC failure requiring intubation can be rapid

General Nursing Considerations

  • Titrate to target SpO₂ — typical targets: 94–98% (general), 88–92% (COPD/hypercapnic risk). Follow the provider order.
  • Never give "more oxygen is better" — hyperoxia causes vasoconstriction, worsened outcomes in MI and stroke, and can precipitate hypercapnia in COPD (via V/Q mismatch and the Haldane effect — titrate to 88–92%, do not withhold O₂).
  • Ensure humidification at higher flows to prevent mucosal injury.
  • Assess skin integrity regularly — nasal cannula prongs, mask edges, and tubing cause pressure injuries.
  • Verify connections and reservoir bag inflation before applying any mask device.
  • Document: device type, flow rate/FiO₂ setting, SpO₂ response, and patient tolerance.

Standards & sources

Fact-checked Jun 21, 2026

This page is written to align with American Association for Respiratory Care (AARC) · GOLD (COPD) / ATS / CHEST. It is an educational summary, not a citation of any single document — always verify specific doses, values, and protocols against current guidelines and your facility policy. How we source content →