Automatic oxygen administration and weaning in patients following mechanical ventilation

J Crit Care. 2021 Feb:61:45-51. doi: 10.1016/j.jcrc.2020.10.005. Epub 2020 Oct 10.


Purpose: To evaluate efficacy of FreeO2 device in oxygen weaning of patients after being liberated from mechanical ventilation (MV).

Methods: Prospective crossover cohort study in patients admitted to ICU and after MV weaning. FreeO2 curves were recorded during constant flow and FreeO2 modes. Oxygenation parameters and O2 consumption were assessed.

Results: Fifty one records were obtained in 51 patients (median age, 62 years, 54.9% had COPD, admission for acute respiratory failure in 96%). NIV was used initially in 68.6%. For a median records duration of 2.04 h, the time spent within target SpO2 range was significantly higher with FreeO2 mode compared to constant O2 flow mode [86.92% (77.11-92.39) vs 43.17% (5.08-75.37); p < 0.001]. Time with hyperoxia was lower with FreeO2 mode: 8.68% (2.96-15.59) vs 38.28% (2.02-86.34). Times with hypoxaemia, and with severe desaturation, were similar. At the end of FreeO2 mode, O2 flow was lower than 1 l/min in 28 patients (54.9%), with a median of 0.99 l/min.

Conclusions: For the purpose of oxygen weaning in patients recovering from MV, automatic O2 titration with FreeO2 was associated with a substantial reduction in O2 delivery and better oxygenation parameters in comparison with constant O2 flow.

Keywords: Automatic oxygen administration; Hyperoxia; Intensive care unit; Weaning.

MeSH terms

  • Cohort Studies
  • Cross-Over Studies
  • Humans
  • Middle Aged
  • Oxygen*
  • Prospective Studies
  • Respiration, Artificial*
  • Ventilator Weaning


  • Oxygen