Association between hyperoxia and mortality after stroke: a multicenter cohort study.

Area of Science:

• Critical Care Medicine
• Neurology
• Pulmonary Medicine

Background:

• Ventilated stroke patients in the ICU face risks from abnormal blood oxygen levels.
• Hyperoxia (high PaO2) and hypoxia (low PaO2) are common in this patient group.
• The impact of hyperoxia on mortality in ventilated stroke patients remains unclear.

Purpose of the Study:

• To investigate the association between arterial hyperoxia and in-hospital mortality in mechanically ventilated stroke patients.
• To compare mortality rates between hyperoxic, normoxic, and hypoxic ventilated stroke patients.

Main Methods:

• Retrospective multicenter cohort study of 2,894 ventilated stroke patients across 84 US ICUs (2003-2008).
• Patients categorized into hyperoxia (PaO2 ≥ 300 mm Hg), hypoxia (PaO2 < 60 mm Hg or PaO2/FiO2 ≤ 300), and normoxia groups.
• In-hospital mortality was the primary outcome measure.

Main Results:

• Hyperoxia was identified in 16% of patients, hypoxia in 46%, and normoxia in 38%.
• Crude mortality was significantly higher in the hyperoxia group compared to normoxia (OR 1.7) and hypoxia (OR 1.3).
• Multivariable analysis confirmed hyperoxia was independently associated with increased in-hospital mortality (aOR 1.2).

Conclusions:

• Arterial hyperoxia is independently associated with higher in-hospital mortality in ventilated ICU stroke patients.
• These findings highlight the need for controlled reoxygenation strategies in this population.
• Avoidance of unnecessary oxygen administration is recommended in ventilated stroke patients pending further clinical trials.