UTMI
What is ETCO2
EtCO2 is end-tidal carbon dioxide, which refers to the concentration of CO2 in the patient's end-tidal gas, which is monitored by an infrared sensor.
What is the principle of ETCO2 monitoring?
The principle is that CO2 absorbs infrared light. The higher the concentration, the more the absorption. The instrument receives the data and images obtained by the main control chip after receiving it through the infrared sensor j.
The clinical significance of end-tidal carbon dioxide monitoring
Monitoring of ventilation function: In most cases, the partial pressure of carbon dioxide at the end of expiration can accurately reflect the partial pressure of carbon dioxide in the arterial blood to judge the ventilation status of the animal.
Determine the position of the endotracheal tube: An ETCO2 waveform greater than 30 mmHg indicates that the endotracheal tube is in the airway.
Reflect circulatory function: When ETCO2 is greater than 10-15mmHg, it means that the lung has better blood flow. In hypotension, hypovolemia, shock and heart failure, ETCO2 gradually decreases with the decrease of pulmonary blood flow.
The mechanical failure of the ventilator was found in time: the tracheal tube connector fell off, ETCO2 could quickly drop to zero, and ETCO2 increased sharply after aspiration. Adjust ventilator parameters and guide anesthesia.
Mainstream: direct sampling method, that is, the infrared sensor is directly placed on the tracheal tube connector for measurement;
The mainstream application area is smaller than the side flow, but the disadvantage is that it needs to be preheated, and the analysis results are easily affected by water vapor, which often causes the measured value to be too large by 3-6mmHg. The advantages are fast response, long service life of consumables, and the sensor itself is not easy to be damaged.
Mainstream CO2 Connection Diagram
Connecting the CO2 Sensor Cable
1. Plug the CO2 sensor cable into the CO2 socket on the side panel of the monitor.
2. Select the appropriate mainstream airway adapter
Choose the appropriate airway adapter based on the size of the patient, the diameter of the endotracheal tube, and the monitoring environment.
3. Embed the airway adapter on the CO2 sensor
When connecting the airway adapter to the sensor, make sure the window of the airway adapter is clean and dry, and clean or replace the airway adapter if necessary. Place the airway adapter on the CO2 sensor and wait for the airway adapter and sensor to warm up. The prompt message "Preheating" is displayed on the screen, and the sensor and airway adapter have reached the working temperature at this time. When the sensor warm-up is completed, the prompt message disappears.
Sidestream sampling, that is, indirect sampling
Advantages of side-stream consumables: The infrared measurement optical path is made on the water removal consumables, and the optical path is made into a structure that can be plugged and replaced. In this way, if water vapor enters the optical path, the measurement can be resumed simply by replacing the consumable without damaging the module itself.
Bypass CO2 Connection Diagram
1. Connect the CO2 module cable
Plug the CO2 module cable into the CO2 socket on the side panel of the monitor.
2. Connect the tubing, airway adapter or sampling tube
Attach tubing, airway adapters, or sampling tubing to the sensor as needed.
3. Insert the sampling tube into the sampling tube interface. If the sampling pump is not turned on or the sampling pump runs intermittently, you need to perform zero calibration according to Section 5.6.4.
4. Make sure that the exhaust pipe of the CO2 module has exhausted all gas out of the surrounding environment of the module;
5. Wait for the CO2 module to warm up. The prompt message "Preheating" is displayed on the screen, and the module is heating up to the working temperature at this time. When the module is preheated, the prompt message disappears.
6. After the warm-up is complete, the measurement can be started.
