A retrospective cohort study evaluated combined carbon dioxide power (CO2CP) as a predictor of mortality in unplanned intensive care unit (ICU) transfers. The study analyzed 101 adult patients with unplanned transfer to the ICU, with CO2CP levels measured within 8 hours before transfer. The results showed that CO2CP had a better predictive ability of mortality (AUC = 0.722) compared to the modified early warning score (MEWS) (AUC = 0.5204). Lower CO2CP values were associated with worse ICU patient survival (log-rank P = 0.003). Multivariable analysis confirmed that CO2CP was an independent predictor of mortality (OR approximately 0.87 per 1 mmol/L increase, p < 0.001). The combination of CO2CP and MEWS improved the discriminative power of the model, although the clinical utility of this combination requires further validation. The authors recommend further prospective studies to confirm these findings.