Conservative oxygen therapy in mechanically ventilated patients following cardiac arrest: A retrospective nested cohort study

Glenn M. Eastwood, Aiko Tanaka, Emilo Daniel Valenzuela Espinoza, Leah Peck, Helen Young, Johan Mårtensson, Ling Zhang, Neil J. Glassford, Yu Feng Frank Hsiao, Satoshi Suzuki, Rinaldo Bellomo

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)


Background: In mechanically ventilated (MV) cardiac arrest (CA) survivors admitted to the intensive care unit (ICU) avoidance of hypoxia is considered crucial. However, avoidance of hyperoxia may also be important. A conservative approach to oxygen therapy may reduce exposure to both. Methods: We evaluated the introduction of conservative oxygen therapy (target SpO2 88-92% using the lowest FiO2) during MV for resuscitated CA patients admitted to the ICU. Results: We studied 912 arterial blood gas (ABG) datasets: 448 ABGs from 50 'conventional' and 464 ABGs from 50 'conservative' oxygen therapy patients. Compared to the conventional group, conservative group patients had significantly lower PaO2 values and FiO2 exposure (p < 0.001, respectively); more received MV in a spontaneous ventilation mode (18% vs 2%; p = 0.001) and more were exposed to a FiO2 of 0.21 (19 vs 0 patients, p = 0.001). Additionally, according to mean PaO2, more conservative group patients were classified as normoxaemic (36 vs 16 patients, p < 0.01) and fewer as hyperoxaemic (14 vs 33 patients, p < 0.01). Finally, ICU length of stay was significantly shorter for conservative group patients (p = 0.04). There was no difference in the proportion of survivors discharged from hospital with good neurological outcome (14/23 vs 12/22 patients, p = 0.67). Conclusions: Our findings provide preliminary support for the feasibility and physiological safety of conservative oxygen therapy in patients admitted to ICU for MV support after cardiac arrest (Trial registration, NCT01684124).

Original languageEnglish
Pages (from-to)108-114
Number of pages7
Publication statusPublished - Apr 1 2016
Externally publishedYes


  • Cardiac arrest
  • Intensive care
  • Mechanical ventilation
  • Mortality
  • Outcome
  • Oxygen

ASJC Scopus subject areas

  • Emergency Medicine
  • Emergency
  • Cardiology and Cardiovascular Medicine


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