Utility of End Tidal Carbon Dioxide Monitoring in Patients of Shock Presenting to the Emergency Department

Shock is a critical, life-threatening syndrome defined by a state of global hypoperfusion that results in inadequate oxygen and nutrient delivery to tissues, leading to cellular dysfunction and ultimately, organ failure. Despite advancements in critical care, shock continues to be associated with alarmingly high mortality rates, cited as high as 23.1% at 7 days and 40.7% at 90 days.

To study the utility of end tidal carbon dioxide (ETCO2) monitoring in shock patients.

A prospective observational study was conducted among 150 patients who were admitted at Emergency Medicine Department of Dr. D. Y. Patil Medical College, Hospital, and Research Centre, Pimpri, Pune.

The mean age of the cases was 51.2 ± 21.01 years, and males constituted 57.3%. Septic shock was the predominant subtype, followed by hypovolemic and cardiogenic shock. Serial monitoring demonstrated a gradual rise in ETCO2 values from 17.89 mmHg at 0 min to 23.24 mmHg at 360 min, suggesting partial improvement in perfusion. Correlational analyses showed no significant association between ETCO2 and mean arterial pressure during the early resuscitation phase, but a weak yet statistically significant positive correlation appeared after 240 min. Clinical outcomes at 6 h showed that 78% of patients improved, 17.3% deteriorated, and early mortality occurred in 4.7%.

ETCO2 showed a meaningful inverse correlation with serum lactate during the later stages of resuscitation, suggesting that rising ETCO2 may indicate improving tissue perfusion and metabolic recovery. These findings highlight the potential utility of serial ETCO2 measurements as a dynamic marker of resuscitation response.