Method Of Leak Detection Before Use In Anesthesia Machine

- Jun 21, 2018-

The anesthesia machine can accurately control the concentration of inhaled anesthetics and provide a stable oxygen inhalation, which helps the doctor to ensure the safety ventilation of the patient during the operation. The doctor guarantees the safety of the patient during the operation, and the preparatory work before the anesthesia machine is the first prerequisite to ensure that the instrument can safely and steadily assist the doctor to complete the anesthesia smoothly.

The most important task of the preparation work before the anesthesia machine is the leak detection of the anesthesia machine. This includes both the leakage of the anesthetic circuit and the anesthetic circuit and the leakage inside the anesthesia machine.

Because the internal leakage of the anesthesia machine is generally not easy to find and non-professionals cannot solve it, the doctor basically observes the appearance and prompts when using it, without having to disassemble the instrument housing for testing. Connect the gas source tube of the anesthesia machine to the oxygen gas source terminal. Gently shake the gas source hose near the plug that is near the center of the oxygen supply to confirm that there is no leakage of high-pressure gas. And observe whether the indicator of the oxygen source pressure gauge on the anesthesia machine points to the 0.4MP position, or whether the pointer is in the middle of the “green” range of the pressure gauge and keep it still. Near the back of the anesthesia machine, there is a “beep----” leak sound inside the instrument. If there is no abnormal sound, anesthetic circuit leak detection is performed.

Anesthesia loop detection requires the anesthesia circuit to be in the "locked state" to ensure that the ACGO switch is off. First, plug the plug of the anesthetic pipeline into the plug of the anesthesia circuit, connect the manual bladder, install the sodium lime tank, and turn the wrench switch of the anesthesia circuit to the “manual” position. At this time, the instrument screen is also displayed. Is in manual mode. Close the APL valve, close the flowmeter, and make sure that the airway pressure gauge needle of the anesthetic circuit is pointing to "0". Use the "fast oxygen supply" switch to send air, you can see the manual bladder gradually expand, observe the airway pressure gauge pointer rises to about 30cmH2O position, relax fast oxygen switch. At this point the gas fills the entire anesthesia circuit. Observing the airway pressure gauge for more than 10 seconds, the hands are at rest (the pressure does not decrease) and the anesthesia circuit and the pipeline are leak free. If the pointer slowly drops, it means there is a small amount of leakage in the circuit. It is necessary to check whether each connection interface is tightly closed. It is necessary to use a hose to short circuit the inhalation and exhalation ports of the circuit to eliminate the leakage of the anesthetic circuit. The common circuit leak location is the sodium lime tank part, the one-way valve seal ring, the manual bladder, and the stagnant water cup are not tightened, and the airway pressure gauge can be inserted well.

The manual air leakage test passed and the APL valve was used to release the gas from the anesthesia circuit. It was determined that the use of the APL valve was normal. After the wrench is turned to the “machine control” position, the instrument screen will also switch to the machine control icon. Connect the anesthesia circuit to the manual bladder and use the quick oxygen supply button to raise the enclosure to maximum, at which time the manual bladder is also inflated. When using the quick oxygen switch to send air to the circuit, observe the pointer on the air source pressure gauge and the drop level should not be lower than the green safety range of the dial. According to the set parameters of the machine, the machine simulates ventilation, observes whether there is any abnormality in the movement of the folding bellows of the instrument, and the top of the bellows cover can indicate that the instrument is in a controlled state without leakage during each rebound of the bellows. Whether the ventilation value is consistent with the set value. The air leakage in the machine-controlled venting is sometimes caused by the fact that the anesthetic vaporizer has failed to place the bypass valve firmly, or the seat seal leaks out due to aging, and the closure of the evaporator dosing port has not been tightened.

The detection of leakage before the anesthesia machine is the most important task to ensure the anesthetic safety during the operation. Once the instrument leaks during the operation, the possibility of downtime detection is almost impossible, which may cause serious consequences. The after-sales department will receive an intraoperative report of faults related to anesthetic machine leaks, and these failures are related to the operator's failure to perform a complete instrument leak detection before surgery.