How do I adjust the oxygen tank meter for a non-rebreather (NRB) mask?

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Last updated: November 26, 2025View editorial policy

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Oxygen Flow Rate for Non-Rebreather Mask

Set the oxygen flow meter to 15 L/min when using a non-rebreather mask. This is the standard flow rate that delivers oxygen concentrations between 60% and 90% and is specifically recommended for trauma and emergency situations. 1

How to Adjust the Flow Meter

  • Locate the flow meter attached to either the oxygen cylinder or wall oxygen outlet 1
  • Align the center of the floating ball with the 15 L/min marking on the flow meter scale 1
  • Verify the cylinder is not empty before connecting the mask—check the pressure gauge on portable cylinders 1
  • Ensure proper connections at both ends of the oxygen tubing to prevent accidental connection to compressed air outlets instead of oxygen 1

Clinical Context and Monitoring

The 15 L/min flow rate is specifically designed for non-rebreather masks to:

  • Maintain adequate reservoir bag inflation during patient inspiration 1
  • Deliver high-concentration oxygen (60-90%) for critically ill or severely hypoxemic patients 1
  • Prevent rebreathing of exhaled gases by ensuring sufficient flow 1

Target oxygen saturation should be 94-98% for most patients without risk of CO2 retention, or 88-92% for patients with COPD or other hypercapnic risk factors. 1, 2

Important Safety Checks

  • Never use flow rates below 15 L/min with a non-rebreather mask, as this compromises oxygen delivery and may cause inadequate reservoir bag filling 1
  • Verify you're using an oxygen outlet, not compressed air—air flow meters should be removed from wall sockets or covered when not in use 1
  • Check mask fit to ensure proper seal, as delivered oxygen concentration depends on both flow rate and mask positioning 1
  • Monitor the patient within minutes of initiating therapy and obtain arterial blood gases if critically ill or if saturation remains below target 2

When to Adjust or Change Devices

  • Once stabilized, you can titrate down to nasal cannulae (1-6 L/min) or simple face mask (5-10 L/min) to maintain target saturation 1
  • If saturation remains inadequate despite 15 L/min via non-rebreather mask, seek senior medical advice immediately and consider alternative oxygen delivery methods 1, 2

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Oxygen Therapy for Desaturating Pneumonia

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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