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Conservative Oxygen Therapy in Mechanically Ventilated Patients: A Pilot Before-and-After Trial*

Suzuki, Satoshi MD, PhD1; Eastwood, Glenn M. PhD1; Glassford, Neil J. MD, MRCP1; Peck, Leah RN1; Young, Helen RN1; Garcia-Alvarez, Mercedes MD1; Schneider, Antoine G. MD1; Bellomo, Rinaldo MD, FCICM1,2

doi: 10.1097/CCM.0000000000000219
Clinical Investigations

Objectives: To assess the feasibility and safety of a conservative approach to oxygen therapy in mechanically ventilated ICU patients.

Design: Pilot prospective before-and-after study.

Setting: A 22-bed multidisciplinary ICU of a tertiary care hospital in Australia.

Patients: A total of 105 adult (18 years old or older) patients required mechanical ventilation for more than 48 hours: 51 patients during the “conventional” before period and 54 after a change to “conservative” oxygen therapy.

Interventions: Implementation of a conservative approach to oxygen therapy (target SpO2 of 90–92%).

Measurements and Main Results: We collected 3,169 datasets on 799 mechanical ventilation days. During conservative oxygen therapy the median time-weighted average SpO2 on mechanical ventilation was 95.5% (interquartile range, 94.0–97.3) versus 98.4% (97.3–99.1) (p < 0.001) during conventional therapy. The median PaO2 was 83 torr (71–94) versus 107 torr (94–131) (p < 0.001) with a change to a median FIO2 of 0.27 (0.24–0.30) versus 0.40 (0.35–0.44) (p < 0.001). Conservative oxygen therapy decreased the median total amount of oxygen delivered during mechanical ventilation by about two thirds (15,580 L [8,263–29,351 L] vs 5,122 L [1,837–10,499 L]; p < 0.001). The evolution of the PaO2/FIO2 ratio was similar during the two periods, and there were no difference in any other biochemical or clinical outcomes.

Conclusions: Conservative oxygen therapy in mechanically ventilated ICU patients was feasible and free of adverse biochemical, physiological, or clinical outcomes while allowing a marked decrease in excess oxygen exposure. Our study supports the safety and feasibility of future pilot randomized controlled trials of conventional compared with conservative oxygen therapy.

Supplemental Digital Content is available in the text.

1Department of Intensive Care, Austin Hospital, Heidelberg, VIC, Australia.

2Australian and New Zealand Intensive Care Research Centre, Melbourne, VIC, Australia.

* See also p. 1553.

This work was performed at the Department of Intensive Care, Austin hospital, Heidelberg, VIC, Australia.

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Supported, in part, by the Austin Hospital Intensive Care Trust Fund.

The authors have disclosed that they do not have any potential conflicts of interest.

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© 2014 by the Society of Critical Care Medicine and Lippincott Williams & Wilkins