End-Tidal CO2 as a Predictor of Clinical Outcomes in Emergency Care

Authors

• Grazia Guarnera, University of LynchburgFollow

Advisor

Dr. Elijah Salzer

Abstract

While early identification of physiologic deterioration is a cornerstone of emergency care, traditional vital signs often fail to detect occult shock or metabolic compromise during the critical compensatory phase. This study positions EtCO₂ as a high-sensitivity marker capable of bridging this diagnostic gap. A comprehensive review of electronic databases, including PubMed, examined studies that assessed the relationship between EtCO₂ levels and patient outcomes. A systematic synthesis of diverse emergency presentations, including sepsis, trauma, and cardiac arrest, reveals a consistent inverse correlation between EtCO₂ levels and patient acuity. The data identifies EtCO₂ as a reliable proxy for systemic perfusion and metabolic stress, often preceding overt hemodynamic collapse. These findings support EtCO₂ as a meaningful, noninvasive marker of physiologic stress that can identify clinical compromise before overt hemodynamic instability develops. This project contributes to existing literature by reinforcing the clinical value of initiating EtCO₂ monitoring early in the assessment process, rather than reserving it for advanced deterioration or airway management. Earlier integration into routine evaluation may strengthen risk stratification, support timely intervention, and improve patient outcomes. Although variability in measurement timing and patient populations limits the establishment of universal threshold values, the overall body of evidence supports broader implementation. To translate these findings into clinical practice, future research must prioritize the validation of standardized, early-measurement protocols. Integrating EtCO₂ into automated risk-stratification tools offers a viable pathway to reducing diagnostic latency and improving survival outcomes in the acute setting.

Recommended Citation

Guarnera G. End-Tidal CO2 as a Predictor of Clinical Outcomes in Emergency Care. University of Lynchburg DMSc Doctoral Project Assignment Repository. 2026; 8(1).