How many types of anesthesia machines are there?
Types of anesthesia machines
(1) Air anesthesia machine
The air anesthesia machine is a semi-open anesthesia device. It is mainly composed of a liquid medicine tank, an ether adjustment switch, a folding bellows, a one-way valve for inhalation and exhalation, and a bellows. As shown in Figure 2-1-1. The device is light and suitable, can directly use air and oxygen as carrier gas, can perform assisted breathing and controlled breathing, and meet various surgical requirements.
Its working principle is: after the patient completes the induction of anesthesia, the air anesthesia machine is connected with a closed mask or tracheal tube. When inhaling, the anesthetic mixed gas enters the patient through the opened inhalation valve; when exhaling, the exhalation valve is opened, and the inhalation valve is closed at the same time, expelling the exhaled air. When using auxiliary or controlled breathing, a folding bellows can be used. Depress during inhalation and pull up during exhalation to ensure that the patient has sufficient ventilation. At the same time, adjust the ether switch to maintain a stable anesthesia level according to actual needs.
The disadvantage of this device is that the concentration of ether is low, which can only be used as the maintenance of anesthesia, and the consumption of ether is large, which is easy to cause environmental pollution.
Principle picture of air anesthesia machine and DC anesthesia machine
(2) DC anesthesia machine
The direct current anesthesia machine is composed of high-pressure oxygen, a pressure reducer, a flow meter, and an anesthetic liquid vaporizer. As shown in Figure 2-1-2. The device can only provide oxygen and adjust the concentration of anesthetic in the inhaled gas, and other devices must be connected in series with the output site to perform anesthesia.
(3) Circulating closed type anesthesia machine
The device uses low-flow anesthesia mixed gas to supply the patient with one-way movement through the escape valve (door). The exhaled gas enters the CO2 absorber through the exhalation valve and is reused. Its structure is mainly composed of oxygen and nitrous oxide supply device, gas flow meter, evaporator, CO2 absorber; one-way valve, breathing pipeline, escape valve, storage air bag, etc., as shown in Figure 2-1-3 Show.
Circulating closed anesthesia machine principle picture
Modern anesthesia machines are also equipped with ventilator airway internal pressure, expiratory flow, end-tidal CO2 concentration, inhaled anesthetic concentration, oxygen concentration monitor, hypoxia alarm and hypoxia-nitrous oxide automatic protection device. Figure 2-1-4 is an actual anesthesia gas circuit diagram. This is a closed loop anesthesia circuit. Before performing anesthesia, first give the patient a certain amount of pure oxygen (usually 3 to 5 minutes), and then perform anesthesia manipulation.
Principle picture of anesthesia machine gas circuit diagram
1. Anesthetic liquid evaporator 2. Oxygen flow meter 3. Nitrous oxide flow meter 4. Nitrous oxide inlet 5. Oxygen inlet
6. Pure oxygen supply button 7. Mixed anesthetic gas delivery pipe 8. Oxygen pressure gauge 9. Nitrous oxide pressure gauge 10. Oxygen failure protection device
11. Anesthesia gas outlet 12. Inhalation biometrics 13. Exhalation bellows 14. Three-way connector 15. Face mask
16. Exhalation active detection 17. CO2 absorber 18. Outgas active identification 19. Excess gas escape outlet 20. Bellows
21. Air storage bladder 22. Adult-child switch
