Anesthesia refers to the method of temporarily or completely deactivating the organism for surgical treatment. There are several methods of anesthesia, such as acupuncture anesthesia, injection anesthesia and inhalation anesthesia. The current method of general anesthesia in hospitals is still based on inhaled anesthesia.
The anesthesia machine is an instrument for general anesthesia using inhalation anesthesia. The modern anesthesia machine is developing towards an intelligent and integrated system. The components are coordinated, flexible, reliable, compact and reasonable in use. The interface is clear and friendly, and the operation is convenient and quick. Electronically controlled gas delivery system Built-in electronically controlled anesthetic ventilator, integrated breathing circuit, integrated gas monitoring system. The high and low flow rate of anesthesia is the best combination of modern anesthesia machines.
The new generation of anesthesia workstations will be expanded into the entire medical system, which will be able to network with hospital equipment, communicate, define, adjust the anesthesia process and record the assessment of anesthetic effects to improve patient care quality. Create a good working atmosphere for clinicians.
The structure principle of modern anesthesia machines can be divided into: gas supply delivery system, anesthetic gas volatilization tank, breathing circuit, anesthesia ventilator, safety monitoring system and residual gas removal system.
1. Gas supply and delivery system
The gas supply system includes a compressed air cylinder or central air source, a check valve, an overflow valve, a filter, a pressure gauge, a gas pressure regulator, a flow meter and an N2O/O2 proportional interlock control device, a laugh oxygen stop valve, and the like. The anesthesia machine must be equipped with various air flow meters. Flowmeter units are L / min and mL / min (or less than 2L / min flow tubes) Two reading flow tubes for low flow anesthesia implementation. At the same time, a N2O/O2 proportional interlocking control device must be provided to ensure that the oxygen concentration of the output anesthetic gas is not less than 25%; when the oxygen supply is insufficient or interrupted, the laughing gas supply is automatically cut off. The common N2O/O2 ratio interlocking control device and Oxygen Oxygen stop valve are mechanical devices. Beware of failure. During daily use, the O2/N2O ratio must be observed to check whether the flow meter leaks. The O2/N2O concentration in the breathing circuit can be monitored by anesthesia machine or other monitoring system to accurately measure the current situation of anesthesia machine operation. Many modern anesthesia machines have an oxygen bypass of 55L/min, and can quickly enter the breathing circuit directly through the emergency interface, which greatly facilitates the oxygen supply operation of clinical anesthesiologists.
2, anesthetic gas volatilization tank
Volatile can is an important part of the anesthesia machine. Its quality not only indicates that the level of anesthesia machine is also related to the effect and success of inhalation anesthesia, but also relates directly to the safety of the patient. The basic principle of the volatilization tank is to change the anesthetic drug into evaporation gas by utilizing changes in the ambient temperature and heat source, and a certain amount of carrier gas, a part of which carries the saturated anesthetic gas into a gas stream with a certain concentration of anesthetic vapor, directly enters the anesthesia. Loop.
3, breathing circuit
The breathing circuit is a combined air circuit device connected between the anesthesia machine and the patient, delivering the anesthetic gas mixture to the patient and returning the exhaled gas to the patient, thereby achieving a normal oxygen and carbon dioxide gas exchange. Mainly by the breathing pipe, CO2 absorption tank, suction valve, storage balloon, mask, machine control manual valve, exhaust valve, pressure limiting valve, development / semi-open valve and other components. The directional circulation of the gas formed by the flaps and the pipes utilizes the sodium lime in the CO2 absorption tank to absorb CO2 and moisture to supply fresh gas to the patient. The mechanically controlled manual valve facilitates manual control of the user or the choice of machine control through the anesthesia ventilator. Semi-open valves, pressure limiting valves, etc., allow the breathing circuit to flexibly control the pressure limit, which is conducive to spontaneous breathing.
4, anesthesia breathing machine
Anesthesia ventilators have become an integral part of anesthesia machines. Mechanical ventilation due to inhalation anesthesia has developed rapidly in recent years and has become fully functional and miniaturized. The anesthesia ventilator is driven pneumatically, pneumatically and electrically. The new type of anesthesia machine supporting anesthesia ventilator is mostly oxygen-driven electro-pneumatic type. The recent anesthesia ventilator is a built-in electric electronically controlled ventilator, which does not require a driver to provide ventilation by air supplementation in the event of a loss of air, ensuring the safety of patients. . A typical anesthetic ventilator is a pneumatic and electrically controlled ventilator. The inside and outside of the folded bag in the transparent sealing cover are respectively two air circuit circuits. The driving gas compresses the folding bag and drives the capsule anesthetic gas to enter the patient to form the driving gas source. Anesthetic airflow two loop system.
4, security monitoring system
Modern anesthesia machines have safety monitoring systems. The system includes an oxygen deficiency alarm, an oxygen deficiency/interruption laughter cut-off device, a capacity and concentration monitoring section, and a fault alarm. The monitoring part mainly includes inhaled oxygen concentration, exhaled tidal volume, airway pressure, minute ventilation, end-tidal CO2 concentration, and anesthetic gas concentration. The use of microcomputers to process and display data, together with an alarm device system, in particular, respiratory, circulatory, neurological, and muscular monitoring functions can be achieved, greatly improving the quality of clinical anesthesia and patient safety, and improving the success rate of surgery. .
5, residual gas removal system
The residual gas removal system collects the excess residual gas in the anesthesia machine and exhaust gas exhaled by the patient and discharges it through the pipeline to the operating room to avoid air pollution in the operating room. It mainly includes exhaust gas collection and discharge devices, which are composed of regulating valves, discharge valves, vacuum generators, pipes and connectors.
