Anesthesia and ventilation equipment is an essential component in the ICU and OR of the hospital or independent clinic. Patients are ventilated in situations where they cannot do so themselves or are under anesthesia for surgery. A reliable anesthesia/ventilator contributes to patient safety and has a significant impact on the success of the treatment. Proper inspection and maintenance of this equipment is vital.
During preventive maintenance, the maintenance parts are replaced and a general inspection of the device is performed. This is followed by functional testing and measurement of ventilation parameters. These parameters are checked using a ventilator tester, or gas flow analyzer. The ventilation parameters are displayed as follows on the ventilator tester, such as the VT650 or VT900. When using the ventilator tester, there are some important things to keep in mind.
Ventilator tester setting
When checking ventilation functions, always set the ventilator tester to bi-directional. Also, set the units of measure on the ventilator tester as on your ventilator, for example mbar or cmH₂O. Always work with a correct test lung on the expiratory side of the measuring device.
Gas setting
Make sure that the gas setting matches the gas setting of the ventilator. If the ventilator tester is not set correctly, incorrect measurements may be displayed. Often the gas used is compressed air or oxygen, but in practice we see that a different gas setting on the ventilator tester can lead to strange readings.
Gas correction mode
When the gas setting is correct, it is very important to look at the gas correction mode. The three main factors here are: ambient temperature, ambient pressure and humidity. The ventilators are adjusted by the manufacturer to a certain gas correction mode as in the table.
If a different gas correction mode is used during measurement, this will affect the measured values. Therefore, always adjust the gas correction mode to the correction mode of the ventilator manufacturer. This is often indicated in the service manual.
In a future blog, we will discuss more extensive analysis of an anesthesia or ventilation device with the ventilator tester.
