The End-Tidal CO_2 correlation with a decreased cardiac output measured by ultrasonic cardiac output monitor in intubated ICU patients

Background: Assessment of cardiac output is crucial in the management of critically-ill patients. Various types of tool are available to measure cardiac output. However, most has limitations such as invasive, expensive, and require special skill. Assessment of End-tidal Carbon Dioxide (EtCO_2) is expected to be used as an alternative estimation of cardiac output. It is based on the condition that when cardiac output is decreased, it decreased pulmonary blood flow and diffusion of CO_2 into the alveolar, thereby increasing alveolar dead space and lowering EtCO_2. Objective: To find a correlation between EtCO_2 and decreased cardiac output measured by Ultrasonic Cardiac Output Monitor (USCOM) for intubated patients in ICU of Sanglah General Hospital, Denpasar, Bali. Methods: A cross-sectional study was conducted from June to August 2016 in Sanglah General Hospital ICU. The study involved 75 eligible patients with a total population sampling technique. The intubated patients admitted to the ICU were evaluated for EtCO_2 and USCOM in the first 24 hours, simultaneously. The data was tested for normality distribution with a Shapiro-Francia test. A Pearson’s correlation test was run to check the correlations between variables. Results: The EtCO_2 value obtained was positively correlated with cardiac output values (r=0.373 p=0.001). Conclusion: there is a correlation between EtCO_2 and decreased cardiac output measured by USCOM for intubated patients in ICU of Sanglah General Hospital, Denpasar