Arterial and End-Tidal CO2 Gradient as a Mortality Predictor in Critical Care Patients

Scoring systems (SOFA, APACHE-II etc.) are used to estimate the mortality rates of patients treated in the intensive care unit. . In the scoring systems used, the disfunction level of the organs of the patients is measured. Blood gas analysis is routinely performed in patients whom intubated in the intensive care unit and receiving mechanical ventilation support, and the patient's treatment is optimized according to the results of the examination. The patient's mechanical ventilation settings are regulated by analyzing the Partial Arterial Carbondioxide (paCO2) value in the patient's blood gas result. The difference between the paCO2 value in the blood gas and the End-tidal Carbondioxide (EtCO2) value measured in the mechanical ventilator is 3-5mmHg in normal healthy people, while this difference is seen more in critical care patients. In critically ill patients in the intensive care unit, there is a greater increase in the difference between paCO2 and ETCO2 in cases where mortality is high, such as global perfusion disorder, shock situations, and massive pulmonary embolism, etc. In this study, it was planned to investigate the use of the difference between the paCO2 value in the blood gas taken from the patient and the ETCO2 value measured in the mechanical ventilator to predict the mortality rate of the patient.