Oxygen-Saturation Targets for Critically Ill Adults Receiving Mechanical Ventilation

N Engl J Med. 2022 Nov 10;387(19):1759-1769. doi: 10.1056/NEJMoa2208415. Epub 2022 Oct 24.


Background: Invasive mechanical ventilation in critically ill adults involves adjusting the fraction of inspired oxygen to maintain arterial oxygen saturation. The oxygen-saturation target that will optimize clinical outcomes in this patient population remains unknown.

Methods: In a pragmatic, cluster-randomized, cluster-crossover trial conducted in the emergency department and medical intensive care unit at an academic center, we assigned adults who were receiving mechanical ventilation to a lower target for oxygen saturation as measured by pulse oximetry (Spo2) (90%; goal range, 88 to 92%), an intermediate target (94%; goal range, 92 to 96%), or a higher target (98%; goal range, 96 to 100%). The primary outcome was the number of days alive and free of mechanical ventilation (ventilator-free days) through day 28. The secondary outcome was death by day 28, with data censored at hospital discharge.

Results: A total of 2541 patients were included in the primary analysis. The median number of ventilator-free days was 20 (interquartile range, 0 to 25) in the lower-target group, 21 (interquartile range, 0 to 25) in the intermediate-target group, and 21 (interquartile range, 0 to 26) in the higher-target group (P = 0.81). In-hospital death by day 28 occurred in 281 of the 808 patients (34.8%) in the lower-target group, 292 of the 859 patients (34.0%) in the intermediate-target group, and 290 of the 874 patients (33.2%) in the higher-target group. The incidences of cardiac arrest, arrhythmia, myocardial infarction, stroke, and pneumothorax were similar in the three groups.

Conclusions: Among critically ill adults receiving invasive mechanical ventilation, the number of ventilator-free days did not differ among groups in which a lower, intermediate, or higher Spo2 target was used. (Supported by the National Heart, Lung, and Blood Institute and others; PILOT ClinicalTrials.gov number, NCT03537937.).

Publication types

  • Pragmatic Clinical Trial
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Academic Medical Centers
  • Adult
  • Critical Care / methods
  • Critical Illness* / therapy
  • Cross-Over Studies
  • Emergency Service, Hospital
  • Hospital Mortality
  • Humans
  • Intensive Care Units
  • Oximetry
  • Oxygen* / administration & dosage
  • Oxygen* / blood
  • Oxygen* / therapeutic use
  • Respiration, Artificial* / methods


  • Oxygen

Associated data

  • ClinicalTrials.gov/NCT03537937