Hyperoxaemia and hypoxaemia are associated with harm in patients with ARDS

Andrew J Boyle,Jonathan Hackett,Daniel F Mcauley,Cecilia M O’Kane,Susanna Gilliland,Paul Young,David N Holmes,Michael Mccloskey,Stefania Di Gangi

doi:10.1186/s12890-021-01648-7

Abstract

BackgroundOxygen therapy is routinely administered to mechanically ventilated patients. However, there remains uncertainty about the optimal oxygen titration target in patients with the acute respiratory distress syndrome (ARDS).MethodsProspectively identified adult patients meeting the Berlin definition of ARDS between 1st January 2014 and 13th December 2016 were analyzed. Oxygen exposure variables were collected at 6-hourly intervals. The primary exposure was the average time-weighted partial pressure of arterial oxygen (PaO2) calculated over a maximum of 7 days from meeting ARDS criteria. The primary outcome was ICU mortality. Univariable and multivariable logistic regression analyses were performed to assess the impact of exposure variables on clinical outcomes. Results are presented as odds ratio [95% confidence interval].Results202 patients were included in the final analysis. Overall ICU mortality was 31%. The average time-weighted PaO2 during the first 7 days of ARDS was similar between non-survivors and survivors (11.3 kPa [10.2, 12.5] (84.8 mmHg [76.5, 93.8]) vs. 11.9 kPa [10.9, 12.6] (89.3 mmHg [81.8, 94.5]); p = 0.08). In univariable and multivariable analysis, average time-weighted PaO2 demonstrated a U-shaped relationship with ICU mortality. There was a similar relationship identified with hospital mortality.ConclusionsIn patients with ARDS, the predicted probability of both ICU and hospital mortality was lowest when the average time-weighted PaO2 was between 12.5 and 14 kPa (93.8–105.0 mmHg), suggesting this is a reasonable oxygenation target for clinicians to aim for.

Highlights

Oxygen therapy is routinely administered to mechanically ventilated patients
Between 1st January 2014 and 13th December 2016, 3773 patients were admitted to the intensive care unit (ICU), and of these, 222 patients were identified for inclusion
The average time-weighted Partial pressure of arterial oxygen (PaO2) during the first 7 days of acute respiratory distress syndrome (ARDS) was similar between non-survivors and survivors (11.3 kPa [10.2, 12.5] (84.8 mmHg [76.5, 93.8]) vs. 11.9 kPa [10.9, 12.6] (89.3 mmHg [81.8, 94.5]); p = 0.08)

Summary

Introduction

Oxygen therapy is routinely administered to mechanically ventilated patients. there remains uncertainty about the optimal oxygen titration target in patients with the acute respiratory distress syndrome (ARDS). Supplemental oxygen therapy is routinely required as part of the supportive care of patients with the acute respiratory distress syndrome (ARDS), but it is typically administered without defined or standardized targets [1]. This has prompted oxygenation targets in ARDS to be considered a priority for clinical trials in ARDS [2]. The potentially harmful effects of alveolar hyperoxia were demonstrated in a clinical trial of mechanically ventilated patients with septic shock. This trial was discontinued early, there were fewer ventilator-free days and more serious

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Results

Conclusion