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The purpose of ETCO2 monitoring plays a significant role in diagnosing some respiratory system diseases, assessing the degree of respiratory dysfunction, guiding respiratory management of patients during the perioperative period, emergency rescue, etc. At the same time that the body experiences respiratory physiological dysfunction due to multiple factors, there are often also changes in other system functions such as circulation, nervous system, endocrine metabolism, liver and kidney, etc, and they interact with each other. Lung function has strong compensatory ability, but there are large individual differences and is influenced by multiple factors. Therefore, the results of the measurements must be analyzed in conjunction with specific issues and a comprehensive diagnosis should be made. Therefore, while monitoring ETCO2, other system monitoring should also be carried out comprehensively to avoid neglecting important factors.
Monitoring ventilation function
In patients without obvious heart and lung diseases, ETCO2 can partially reflect PaCO2.
Maintain normal ventilation volume
During general anesthesia or respiratory insufficiency using a ventilator, ventilation volumes can be adjusted based on ETCO2 to avoid inadequate or excessive ventilation and prevent high or low carbon dioxide levels causing symptoms.
Timely detection of mechanical malfunctions of the ventilator
Changes in the ETCO2 waveform can indicate mechanical malfunctions such as disconnection of connections, circuit air leaks, twisting or bending of tubes, tracheal obstruction, failure of the valve, and other mechanical problems. Disconnection of the joint is common between the tracheal tube and the threaded pipe, the threaded pipe and the anesthetic machine, and the connection of the breathing bag, which is easy to occur during head and face surgery, but is difficult for observers to detect due to obstruction. By monitoring ETCO2, disappearance of the carbon dioxide waveform can be detected in a timely manner, accompanied by a sudden drop in tracheal pressure. In case of tube twisting, airway obstruction, or valve failure, the disappearance or marked decrease in the carbon dioxide waveform can be observed, accompanied by a sudden increase in airway pressure. If detected and cleared in a timely manner, it can help reduce the occurrence of safety accidents.
Adjusting ventilator parameters and guiding ventilator removal
Adjusting ventilation volumes; selecting the ideal PEEP (positive end-expiratory pressure ventilation) value, which is generally the PEEP value of the minimum PETCO2 value; ETCO2 allows for continuous noninvasive monitoring and can be used to guide temporary ventilator discontinuation. When the SpO2 and ETCO2 remain normal during spontaneous breathing, the ventilator can be removed. However, attention should be paid to the existence of abnormal ETCO2, and blood gas analysis should be used if necessary for reference.
