Observational studyBMC anesthesiology2026
Arterial and end-tidal CO
Observational study in BMC anesthesiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT05341258 (Arterial and End-Tidal CO2 Gradient as a Mortality Predictor in Critical Care Patients), which is not on this map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Arterial and End-Tidal CO2 Gradient as a Mortality Predictor in Critical Care Patients
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
2 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundMortality prediction in critically ill patients is commonly performed with scoring systems such as SOFA and APACHE II. The arterial-to-end-tidal carbon dioxide gradient [P(a–et)CO₂], which can be obtained from routine blood gas analysis and capnography, may represent a simpler alternative. We investigated the association between this gradient and 28-day mortality in mechanically ventilated ICU patients.
methodsThis prospective observational study included 50 adult patients who had been intubated and had initiated invasive mechanical ventilation within the preceding 24 hours. Simultaneous arterial blood gas analysis and mainstream capnography were used to calculate the P(a–et)CO₂ gradient. Demographic data, comorbidities, vasopressor use, SOFA and APACHE II scores, PaO₂/FiO₂ ratio, ICU length of stay, ventilator days, and 28-day mortality were recorded. Statistical analysis included ROC curves and multivariable logistic regression. To ensure model robustness and prevent overfitting, internal validation was performed using 1,000 bootstrap resamples.
resultsNon-survivors had a significantly higher median P(a–et)CO₂ gradient than survivors (14.0 [range: 2.0–44.0] vs. 4.0 [range: -3.0–18.0] mmHg, p < 0.001). ROC analysis demonstrated a bootstrapped AUC of 0.890 (95% CI 0.761–0.980), with 12 mmHg as the optimal cut-off (sensitivity 0.78, specificity 0.94). In the internally validated multivariable analysis, the gradient remained independently associated with 28-day mortality (adjusted OR 4.21 per 5 mmHg increase, 95% CI 1.72–10.33, bootstrap p = 0.002). No correlation was found between the gradient and ICU stay or ventilator days.
conclusionThe P(a–et)CO₂ gradient is a simple and valuable physiological marker independently associated with 28-day mortality in mechanically ventilated ICU patients. Its routine availability makes it a practical bedside adjunct for early risk assessment, though these findings warrant external validation in larger, multicenter cohorts.
trial registrationThe study was retrospectively registered at ClinicalTrials.gov (NCT05341258).
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.