Alternative Methods to Endtidal CO₂ Predicting the Outcome of Resuscitation: Glial Fibrillary Acidic Protein and Copeptin

Aim: Using the end-tide carbon dioxide (ETCO2) level to predict the outcome of resuscitation may be misleading. This study investigated the usability of glial fibrillary acidic protein (GFAP) and copeptin levels measured at regular intervals during the resuscitation process as an alternative to the ETCO2 level in the prediction of resuscitation outcome. Materials and Methods: This study was prospectively conducted with patients who were resuscitated at the emergency department of a tertiary hospital. The sample included 31 patients, of whom 18 died and 23 had the return of spontaneous circulation (ROSC). ETCO2, GFAP, and copeptin values were measured at the beginning (1), 20th minute (2), and end (3) of resuscitation and statistically analyzed. Results: When calculated in percent units, the ETCO2 1-2 difference, ETCO2 2-3 difference, GFAP 1-2 difference, and copeptin 2-3 difference statistically significantly differed between the patients who died and those with ROSC (p<0.05). Conclusion: We observed that the GFAP and copeptin levels were not sufficient to guide the decision to terminate resuscitation when examined at the beginning of resuscitation, but changes in these copeptin levels measured in series could predict mortality.