End-tidal carbon dioxide (EtCO2) is the level of carbon dioxide that is released at the end of an exhaled breath. It reflects the adequacy with which carbon dioxide (CO2) is carried in the blood back to the lungs and exhaled. EtCO2 measurement can provide an indication of cardiac output and pulmonary blood flow. EtCO2 monitoring using capnography devices has application across several hospital and pre-hospital settings. Capnography provides a numerical value for EtCO2. Measuring EtCO2 is incredibly useful to healthcare providers (HCPs) and has many different uses to help improve patient care and outcomes. EtCO2 is commonly measured via capnography, which can be used anywhere, but is most commonly used in operating rooms to monitor patients undergoing sedation. It also has other indications, such as measuring cardiac output or monitoring patients in a pre-hospital setting. EtCO2 monitoring can provide insight into respiratory effectiveness, breath by breath, to monitor acute respiratory diseases such as asthma, chronic obstruction pulmonary disease (COPD) and bronchiolitis. EtCO2 concentration is a reliable index of effective heart compression during CPR, which is associated with cardiac output. It can be used to determine how well CPR is being delivered and also predict if there will be another cardiac arrest or event. The average values of EtCO2 are 5% to 6% CO2, which is equivalent to 35-45 mmHg. Anything outside of this range requires investigation. Abnormal readings could be caused by respiratory issues. EtCO2 monitoring is used in various clinical areas like emergency environments, critical care, during sedation practice, in ambulatory settings, and in post-operative recovery units.