Utility of ETCO2 to predict hemorrhagic shock in multiple trauma patients

For identifying hemorrhagic shock in trauma patients, some objective data are needed. The use of base excess (BE) and lactate values have been originated. In this study, it was aimed to determine the usability of end tidal carbon dioxide (ETCO₂) in patients with multiple trauma for recognizing hemorrhagic shock.

Patients who were admitted to the emergency department between June 2019 and February 2020 with highenergy multiple trauma were included in the study. ETCO₂ and BE values were measured. Correlation coefficients were calculated to determine correlations between ETCO₂ and BE levels.

One hundred and twenty-two patients were included in the study. Eighty-nine (73%) were men and 33 (27%) were women, and the mean age of the study population was 38.70 ± 19.18. The mortality rate was 14.8% in the study population. The correlation between ETCO₂ and BE values was significant (r: 0.27) and in the same range in the Bland-Altmann analysis. ETCO₂ levels above 35 were specific for stage 1 hemorrhagic shock. ETCO2 levels below 30 were sensitive for stage 2 and 3 hemorrhagic shocks and when the levels were measured below 22 it was found specific for stage 4 shock. The specificity increased to 99% at levels below 18. The sensitivity for ETCO₂ values below 22 for predicting mortality was 33.33%, the specificity was 89.42%, the positive predictive value was 35.29% and the negative predictive value was 88.57%. The sensitivity for BE values below -10 for predicting mortality was 50%, the specificity was 93.27%, the positive predictive value was 56.25% and the negative predictive value was 91.51%.