End-Tidal Carbon Dioxide (EtCO₂) Module Usage and Maintenance Guide

Introduction of EtCO₂ Module

End-tidal carbon dioxide (EtCO₂) monitoring is achieved through an EtCO₂ monitoring module, which can continuously monitor:

Exhaled CO₂ concentration, Inspired CO₂ concentration, Respiratory rate, Waveform changes.

It is commonly used in patient monitors, anesthesia machines, and ventilators.

Based on sampling method, EtCO₂ monitoring has two types:

Mainstream: The sensor is installed directly at the Y-piece connector of the breathing circuit.

Sidestream: Gas is drawn through a sampling tube and measured inside the module.

EtCO₂ Module Operating Guidelines

① Mainstream ETCO2:

1. Installation and Connection:

Connect the mainstream sensor to the module interface and install the disposable airway adapter.

The airway adapter connects to the breathing circuit and endotracheal tube.

Adult and pediatric adapters must not be mixed.

2. Pre-use Inspection:

Confirm that:

● Waveforms and numerical values are normal;

● Connections are secure;

● Perform zero calibration when necessary.

3. Notes During Use:

● Avoid twisting, pulling, or bending the cable;

● Prevent the sensor from contacting the patient's skin;

● Continuously observe waveform changes

② Sidestream ETCO2:

1. Startup Procedure:

Connect the sampling tube and adapter.

Confirm the system status is normal and check the waveform.

2. Leakage and Blockage Detection:

If leakage or blockage occurs, the alarm should be triggered.

3. Usage Recommendation:

For patients with low tidal volume, the recommended sampling flow rate is:

Approximately 50 ± 10 mL/min

Mainstream EtCO₂ Module Cleaning and Maintenance

① Daily Cleaning

● Use a soft cloth with 70% alcohol for cleaning.

● Clean the sensor surface after removing the disposable adapter.

● Do not soak the sensor in liquid.

● Do not pull the cable forcefully.

② Consumable Maintenance

Replace mainstream airway adapters and sampling tubes regularly.

If blockage or alarm occurs, replace them immediately.

③ Calibration and Performance Maintenance

● Perform regular zero calibration.

● Recalibrate when:

● Environmental conditions change

● Readings become abnormal

● Regularly check response time and accuracy.

If necessary, clean the optical components.

④ Storage and Transportation

Avoid: High temperature, High humidity, Dusty environments, Extreme temperature changes

Store and transport according to specified environmental requirements.

Common Faults and Solutions

No waveform: Check whether the connector is loose or there is leakage.

Low numerical value: Check for air leakage or insufficient sampling.

Abnormal waveform: Condensation or blockage caused by contaminants

Blockage alarm: Replace the sampling tube or adapter.

Summary

The key points for EtCO₂ module maintenance include:

● Correct connection of the breathing circuit;

● Prevention of condensation and contamination;

● Regular replacement of consumables;

● Proper cleaning and calibration.

Standardized operation can improve monitoring stability and extend the service life of the module.