Medicine by the Numbers

A Collaboration of and AFP

Liberal vs. Conservative Oxygen Therapy in Acutely Ill Adults


Am Fam Physician. 2019 Jan 1;99(1):online.


 Enlarge     Print




1 in 71 patients died




1 in 71 patients died

Details for This Review

Study Population: Acutely ill adults, without chronic respiratory illness, requiring hospital admission and with the potential to be exposed to supplemental oxygen

Efficacy End Points: Mortality (in-hospital, 30-day, and longest follow-up) and morbidity (disability at longest follow-up, risk of hospital-acquired pneumonia, any hospital-acquired infection, and length of hospital stay)

Harm End Points: Morbidity and mortality

Narrative: Oxygen has been used to treat acute illness since the late 1800s.1 Often, treatment with oxygen results in the patient becoming hyperoxemic.2 Many health care professionals view supplemental oxygen as harmless, even in the setting of hyperoxemia.3 However, hyperoxemia can have deleterious effects on the cardiovascular, pulmonary, central nervous, and immune systems. Most of its adverse effects are thought to be secondary to reactive oxygen species causing cell death and hyperoxia-induced vasoconstriction.4

In this article, we summarize the Improving Oxygen Therapy in Acute-Illness systematic review and meta-analysis comparing liberal vs. conservative oxygen therapy in adults who are acutely ill.5 The systematic review included 25 randomized controlled trials involving 16,037 patients with the following conditions: sepsis, critical illness, stroke, trauma, myocardial infarction, and cardiac arrest. Oxygen saturation was reported as fraction of inspired oxygen (FiO2), arterial partial pressure of oxygen, arterial oxygen saturation, and peripheral oxygen saturation (SpO2). Studies were excluded if they involved patients who were younger than 18 years, pregnant, had psychiatric disease, were on extracorporeal life support, used hyperbaric oxygen, underwent elective surgery, or included only patients with chronic obstructive pulmonary disease.

In the liberal

Author disclosure: No relevant financial affiliations.


show all references

1. Shultz SM, Hartmann PM. George E Holtzapple (1862–1946) and oxygen therapy for lobar pneumonia: the first reported case (1887) and a review of the contemporary literature to 1899. J Med Biogr. 2005;13(4):201–206....

2. Albin RJ, Criner GJ, Thomas S, Abou-Jaoude S. Pattern of non-ICU inpatient supplemental oxygen utilization in a university hospital. Chest. 1992;102(6):1672–1675.

3. Kelly CA, Lynes D, O'Brien MR, Shaw B. A wolf in sheep's clothing? Patients' and healthcare professionals' perceptions of oxygen therapy: an interpretative phenomenological analysis. Clin Respir J. 2018;12(2):616–632.

4. Helmerhorst HJ, Schultz MJ, van der Voort PH, de Jonge E, van Westerloo DJ. Bench-to-bedside review: the effects of hyperoxia during critical illness. Crit Care. 2015;19284.

5. Chu DK, Kim LH, Young PJ, et al. Mortality and morbidity in acutely ill adults treated with liberal versus conservative oxygen therapy (IOTA): a systematic review and meta-analysis. Lancet. 2018;391(10131):1693–1705.

6. Beasley R, Chien J, Douglas J, et al. Thoracic Society of Australia and New Zealand oxygen guidelines for acute oxygen use in adults: ‘swimming between the flags’. Respirology. 2015;20(8):1182–1191.



Copyright © 2019 by the American Academy of Family Physicians.
This content is owned by the AAFP. A person viewing it online may make one printout of the material and may use that printout only for his or her personal, non-commercial reference. This material may not otherwise be downloaded, copied, printed, stored, transmitted or reproduced in any medium, whether now known or later invented, except as authorized in writing by the AAFP. Contact for copyright questions and/or permission requests.

Want to use this article elsewhere? Get Permissions

CME Quiz

More in AFP

Editor's Collections

Related Content

More in Pubmed


Nov 1, 2019

Access the latest issue of American Family Physician

Read the Issue

Email Alerts

Don't miss a single issue. Sign up for the free AFP email table of contents.

Sign Up Now

Navigate this Article