Rakshit Panwar1,2, Miranda Hardie1, Rinaldo Bellomo3,4, Loïc Barrot5, Glenn M Eastwood3,4, Paul J Young6,7, Gilles Capellier4,5, Peter W J Harrigan1,2, Michael Bailey4. 1. 1 Intensive Care Unit, John Hunter Hospital, Newcastle, Australia. 2. 2 School of Medicine and Public Health, University of Newcastle, Newcastle, Australia. 3. 3 Department of Intensive Care, Austin Hospital, The University of Melbourne, Melbourne, Australia. 4. 4 Australian and New Zealand Intensive Care Research Centre, School of Public Health and Preventive Medicine, Monash University, Melbourne, Australia. 5. 5 Critical Care Unit, University Hospital Besançon and University of Franche-Comté, Besançon, France. 6. 6 Intensive Care Unit, Wellington Hospital, Wellington, New Zealand; and. 7. 7 Medical Research Institute of New Zealand, Wellington, New Zealand.
Abstract
RATIONALE: There are no randomized controlled trials comparing different oxygenation targets for intensive care unit (ICU) patients. OBJECTIVES: To determine whether a conservative oxygenation strategy is a feasible alternative to a liberal oxygenation strategy among ICU patients requiring invasive mechanical ventilation (IMV). METHODS: At four multidisciplinary ICUs, 103 adult patients deemed likely to require IMV for greater than or equal to 24 hours were randomly allocated to either a conservative oxygenation strategy with target oxygen saturation as measured by pulse oximetry (SpO2) of 88-92% (n = 52) or a liberal oxygenation strategy with target SpO2 of greater than or equal to 96% (n = 51). MEASUREMENTS AND MAIN RESULTS: The mean area under the curve and 95% confidence interval (CI) for SpO2 (93.4% [92.9-93.9%] vs. 97% [96.5-97.5%]), SaO2 (93.5% [93.1-94%] vs. 96.8% [96.3-97.3%]), PaO2 (70 [68-73] mm Hg vs. 92 [89-96] mm Hg), and FiO2 (0.26 [0.25-0.28] vs. 0.36 [0.34-0.39) in the conservative versus liberal oxygenation arm were significantly different (P < 0.0001 for all). There were no significant between-group differences in any measures of new organ dysfunction, or ICU or 90-day mortality. The percentage time spent with SpO2 less than 88% in conservative versus liberal arm was 1% versus 0.3% (P = 0.03), and percentage time spent with SpO2 greater than 98% in conservative versus liberal arm was 4% versus 22% (P < 0.001). The adjusted hazard ratio for 90-day mortality in the conservative arm was 0.77 (95% CI, 0.40-1.50; P = 0.44) overall and 0.49 (95% CI, 0.20-1.17; P = 0.10) in the prespecified subgroup of patients with a baseline PaO2/FiO2 less than 300. CONCLUSIONS: Our study supports the feasibility of a conservative oxygenation strategy in patients receiving IMV. Larger randomized controlled trials of this intervention appear justified. Clinical trial registered with Australian New Zealand Clinical Trials Registry (ACTRN 12613000505707).
RCT Entities:
RATIONALE: There are no randomized controlled trials comparing different oxygenation targets for intensive care unit (ICU) patients. OBJECTIVES: To determine whether a conservative oxygenation strategy is a feasible alternative to a liberal oxygenation strategy among ICU patients requiring invasive mechanical ventilation (IMV). METHODS: At four multidisciplinary ICUs, 103 adult patients deemed likely to require IMV for greater than or equal to 24 hours were randomly allocated to either a conservative oxygenation strategy with target oxygen saturation as measured by pulse oximetry (SpO2) of 88-92% (n = 52) or a liberal oxygenation strategy with target SpO2 of greater than or equal to 96% (n = 51). MEASUREMENTS AND MAIN RESULTS: The mean area under the curve and 95% confidence interval (CI) for SpO2 (93.4% [92.9-93.9%] vs. 97% [96.5-97.5%]), SaO2 (93.5% [93.1-94%] vs. 96.8% [96.3-97.3%]), PaO2 (70 [68-73] mm Hg vs. 92 [89-96] mm Hg), and FiO2 (0.26 [0.25-0.28] vs. 0.36 [0.34-0.39) in the conservative versus liberal oxygenation arm were significantly different (P < 0.0001 for all). There were no significant between-group differences in any measures of new organ dysfunction, or ICU or 90-day mortality. The percentage time spent with SpO2 less than 88% in conservative versus liberal arm was 1% versus 0.3% (P = 0.03), and percentage time spent with SpO2 greater than 98% in conservative versus liberal arm was 4% versus 22% (P < 0.001). The adjusted hazard ratio for 90-day mortality in the conservative arm was 0.77 (95% CI, 0.40-1.50; P = 0.44) overall and 0.49 (95% CI, 0.20-1.17; P = 0.10) in the prespecified subgroup of patients with a baseline PaO2/FiO2 less than 300. CONCLUSIONS: Our study supports the feasibility of a conservative oxygenation strategy in patients receiving IMV. Larger randomized controlled trials of this intervention appear justified. Clinical trial registered with Australian New Zealand Clinical Trials Registry (ACTRN 12613000505707).