Oxygen and carbon dioxide targets after cardiac arrest: an updated systematic review
Bibliographic record
Abstract
AIM: To perform an updated systematic review and meta-analysis of oxygen and carbon dioxide targets in patients with sustained return of spontaneous circulation after cardiac arrest. METHODS: Searches were conducted in MEDLINE, Embase, and Evidence-Based Medicine Reviews from August 2019 to March 2025 for randomised trials comparing specific oxygen or carbon dioxide targets in post-cardiac arrest patients. Two investigators independently reviewed trials for relevance, extracted data, and assessed risk of bias. Data were pooled using random-effects models. The certainty of evidence was evaluated using GRADE methodology. RESULTS: Fifteen manuscripts from 12 trials were included. All trials were limited to adult patients, primarily including out-of-hospital cardiac arrests. Five trials evaluated oxygen targets in the prehospital setting, while six evaluated oxygen targets and three evaluated carbon dioxide targets in the intensive care unit setting. Risk of bias was assessed as moderate for most outcomes. Meta-analyses found no differences in survival or favourable functional outcomes when comparing restrictive to liberal oxygen targets in either setting. There was also no difference in outcomes when comparing mild hypercapnia to normocapnia. The certainty of evidence was rated as low to moderate. CONCLUSIONS: Among patients resuscitated from cardiac arrest, neither restrictive oxygen targets nor mild hypercapnia, compared to conventional targets, improved survival or functional outcomes.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.010 | 0.031 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.014 | 0.013 |
| Bibliometrics | 0.009 | 0.008 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.003 | 0.002 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.004 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".