Related Experiment Video
Updated: Nov 16, 2025

Expired CO2 Measurement in Intubated or Spontaneously Breathing Patients from the Emergency Department
Published on: January 29, 2011
Impact of Using a Non-Rebreathing Mask in Patients With Respiratory Failure
Chao-Jui Li1, Yat-Yin Law2, Yan-Ren Lin3
1Department of Emergency Medicine, Kaohsiung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
Background:
Liberal oxygen therapy might increase the mortality rate of patients. Non-rebreathing masks (NRM) are a high-flow, non-invasive oxygen device that can provide oxygen concentration up to 95%. This study aimed to determine the impact of using NRM in patients with respiratory failure.
Methods:
This retrospective cohort study was conducted in four medical institutions in Taiwan from January 2010 to December 2016. The association between mortality and NRM use before receiving ventilator support in patients with respiratory failure in the emergency department was analyzed. Patients were divided into the NRM treatment and no NRM treatment groups. A 1:4 propensity score matching was conducted. Regarding the duration of NRM use, treatments were grouped as 0 h, 0-1 h, 1-2 h, and >2 h.
Results:
A total of 18,749 patients were included, with 1074 using NRM. After propensity score matching, 1028 patients using NRM (0-1 h: 508, 1-2 h: 193, and >2 h: 327) and 4112 patients not using NRM were analyzed. The 30-day mortality rates were 29.1%, 28.5%, 27.5%, and 35.5% in the 0 h, 0-1 h, 1-2 h, and >2 h treatment groups, respectively. Patients with respiratory failure due to pulmonary disease using NRM over 2 h had a higher mortality rate than patients not using NRM (hazard ratio: 1.3, 95% CI: 1.01-1.66).
Conclusions:
Prolonged use of NRM in patients with respiratory failure due to pulmonary disease possibly increases mortality.
Related Concept Videos
Oxygen Delivering System I: Nasal Cannula and Face Mask
Nasal Cannula
A nasal cannula is a lightweight tube split at one end into two prongs and placed in the nostrils. It is typically used to deliver low to medium levels of oxygen.
Suggested flow rate: The suggested flow rate for a nasal cannula typically ranges between 1 and 6 L/min.
Oxygen percentage setting:...
Acute Respiratory Failure-II
The underlying physiological abnormalities that contribute to hypoxemic respiratory failure include:
Acute Respiratory Failure-IV
Acute Respiratory Failure-III
Respiratory Assessment: Purpose and Indications
Objectives and Importance:
The primary goal of respiratory assessment is to evaluate patients at early risk of clinical deterioration. Since respiratory distress often precedes other signs of declining health, breathing patterns and sounds become a...
Acute Respiratory Failure-I
Definition: It is defined by specific criteria based on blood gas measurements. Hypoxemia happens when the partial pressure of oxygen (PaO2) falls below 60 mmHg. At the same time,...

