With the continuous development of medical technology, medical equipment plays an important role in the treatment of diseases. Among them, the ventilator, as an important part of medical respiratory anesthesia equipment, is crucial to supporting the patient's respiratory function. However, little is known about the importance of
ventilator maintenance to its proper functioning and patient safety.
1. The ventilator should be cleaned frequently
The parts of the ventilator that need to be cleaned can be cleaned and disinfected according to the requirements of the ventilator manual. Some parts only need to be cleaned, while some are allowed to be disinfected. These parts mainly include the following:
(1) The outer surface of the main engine and the compression pump: the outer surface of the main engine and the compression pump can be wiped gently with a clean soft damp cloth, once a day or once every other day. If necessary, wipe with a soft cloth soaked in a disinfectant such as a chlorine-containing disinfectant.
(2) Air source filter: The air source filter includes the air compressor pump and the washable air filter in some ventilator hosts. This part is at the air intake end of the air circuit. If it is not cleaned in time, the filter screen will be blocked by dust, which will cause the air in and out of the ventilator to be blocked, increase the load, and affect the life of the compressor pump. The specific cleaning method is: take the filter out of the machine, wash the surface dust with clean water, and then shake or dry it vigorously; or use a vacuum cleaner to suck up the dust, and then put it back to its original position. Generally, it is cleaned every 48 to 72 hours, and routine disinfection is not required.
(3) Electronic components inside the ventilator: The dust on the surface of the electronic components inside the ventilator can be gently sucked off with a low-power vacuum cleaner or gently blown with a special suction ball, or gently cleaned with a clean soft brush. It cannot be soaked in disinfectant, nor can it come into contact with water and oil.
(4) Sensors: Various sensors such as flow rate and pressure are sensitive electronic parts of the ventilator. They cannot be washed with water or soaked in disinfectant to avoid damage to their performance. If necessary, they can be sterilized by gas disinfection. The surface can only be sterilized with 70 100% alcohol cotton ball very carefully and gently wipe clean, some sensors can only be gently dipped in clean water, immediately take out, and dry naturally, do not shake or dry vigorously.
(5) Humidifier: Gently wipe the electronic heating part of the humidifier and the metal part of the temperature control sensor probe with a clean soft damp cloth, and do not soak it in disinfectant, so as not to affect the heating function and reduce its temperature sensitivity. accuracy.
(6) Gas pipeline: The gas pipeline is a part of the ventilator that needs to be sterilized. It should be thoroughly disinfected. You can first wash away the dirt in the pipeline with clean water, and then immerse the pipeline in the prescribed disinfectant for about 1 hour. After taking it out, rinse the disinfectant inside and outside the pipeline with clean water. use.
(7) Air filter: The air filter is installed on the front panel of the ventilator or in the patient's breathing gas pipeline for easy disassembly and replacement. The air filter is generally a disposable part, and the function of the air filter is to filter Remove the bacteria in the gas passage of the ventilator to ensure the cleanness of the gas entering and leaving the patient. The air filter should be replaced regularly according to the relevant requirements of the ventilator manual.
(8) Fuselage and table top: Use soft cloth to remove dirt and dust on the body and table in time. When it needs to be pushed to the laminar flow aseptic ward, the surface needs to be cleaned with disinfectant, and the dirt on the roller part of the rack should be carefully removed.
2. Regularly check the function of the ventilator
Air leak detection: Check the air circuit system of the ventilator, whether there is air leakage in each pipeline, humidification tank, and water bottle interface. Due to the different models and working principles of ventilators, the detection methods are also different. Usually, it can be detected by tidal volume measurement, pressure gauge detection, ear hearing and hand touch.
(1) Tidal volume measurement: First, pre-adjust the tidal volume of the ventilator, connect it to the simulated lung, and measure the tidal volume in the inhalation pipe and the exhalation pipe respectively. If the tidal volumes detected by the two are the same, it means that there is no air leakage. If the tidal volume drops, there is a leak. If an air leak is found, you can use your ears to touch the pipelines with your hands. The leaks often make a "hissing, hissing" sound during ventilation. If the pipeline is damaged or the connection is not tight, you can detect the existence of airflow.
(2) Pressure gauge detection: mainly to check the working pressure and airway pressure of the ventilator. If the working pressure is lower than the set level, it means that the air supply pressure is insufficient or the internal pipeline of the ventilator host is leaking. If the airway pressure is lower than normal, Indicates an air leak in the external piping.
Detection of the alarm system: usually check several functions such as airway pressure alarm, minute ventilation (or tidal volume) alarm, inspired oxygen concentration alarm, suffocation alarm and gas source alarm.
(1) Pressure alarm upper and lower limits: According to the set ventilation parameters, the maximum airway pressure (peak pressure) will be generated in the breathing circuit. 0.29kPa (2 ~ 3 cmn20), using the alarm sound, lights flashing, and at the same time the exhalation valve of the ventilator is open, which can indicate that this function is normal.
(2) Minute ventilation alarm: Minute ventilation is an important indicator to measure whether the patient is fully inhaled. The alarm range should not be set too wide, otherwise it will be meaningless. Usually the upper and lower limits are set at about ±25% of the actual minute ventilation. Check the minute ventilation at multiple points separately, and there should be an alarm.
(3) Power-on self-test: Most high-end and mid-range ventilators have a series of self-test functions such as breathing circuit sealing, exhaled flow sensor, oxygen concentration, and solenoid valve. If the self-test passes, it means that the machine is basically intact. For those ventilators without self-test function, the following methods can be used to make a rough judgment: the flow rate is 24 L per minute, the inspiratory time is 1 s or the tidal volume is 400 mL, the respiratory rate is 15 times/min, and the oxygen concentration is 6o%. At this time, the maximum airway pressure is about 2.45 kPa (25 cmH20) and the minute ventilation is about 6 L per minute, which shows that the machine is basically normal. This method is also applicable to models with self-test function.
(4) Inhaled oxygen concentration check: The patient’s inhaled oxygen concentration is also an important parameter for treatment. The oxygen concentration is generally measured by an oxygen sensor commonly known as an oxygen battery. The oxygen battery is a consumable. The usual lifespan is 6-12 months. The oxygen battery directly affects the accuracy of oxygen concentration monitoring, so the oxygen concentration should be checked frequently. Most high-end and mid-range machines have oxygen concentration self-test. For models without self-test function and no external oxygen concentration meter, the following method can be used to judge simply: Ventilate with pure oxygen and compressed air respectively, and observe the tidal volume. No significant change basically judged that the oxygen concentration was normal.
(5) Apnea alarm: It is an important indicator of the ventilator. You can set the mode of the ventilator to spontaneous breathing, and after more than ten seconds (the apnea time of some models is adjustable), there should be an apnea alarm prompt. Higher-end models will automatically switch from the initially set spontaneous breathing mode to mandatory ventilation mode.
(6) Air source alarm: Remove the oxygen or compressed air one way, and there should be a corresponding alarm indication at this time.
Operation precautions: In terms of operation, it should be noted that the power of the main engine should be started after the air source is connected, that is, the power of the air compressor pump and the oxygen should be turned on first, and the pressure of oxygen and air is balanced, and the sound of air leakage or the alarm sound of the air source disappears. After that, the main unit can be powered on. The shutdown sequence of the ventilator is the opposite, that is, first turn off the power of the main unit, and then turn off the gas source.
Make a record of the daily use of the ventilator every day: the daily working conditions of the ventilator, various maintenance, replacement of accessories and consumables, and calibration should be recorded and filed in time. For example, record the location of maintenance, error or damage degree, time, name, time, quantity of replacement parts, etc., for future verification and convenience for future maintenance.
3. Accessibility check
Trigger Sensitivity Check: Since it is a simulated lung, only pressure trigger sensitivity can be checked. Set the working mode to assisted ventilation mode, and set the trigger sensitivity to the most sensitive position. When the ventilator is in the trigger window, squeeze the simulated lung with your hand, and the ventilator should be triggered.
PEEP check: Check PEEP at multiple points, let the ventilator work for several cycles, observe the pressure waveform or the end-expiratory pressure value of the pressure gauge after stabilization (some models have data size display), the error between the set value and the measured value should be less than 10%. Inhalation and exhalation tidal volume check: Most ventilators have two flow sensors, one at the inhalation end, used to measure the set value of breathing parameters; the other at the exhalation end, used to monitor the actual value and change the tidal volume of the ventilator The amount was observed at multiple points, and the error between the two was within 1O%. The above-mentioned inspections have no faults and can be used for patient treatment. After the ventilator is used once, regardless of the length of time, in order to avoid cross-infection, the pipeline must be strictly disinfected, and there are methods such as drug soaking, gas fumigation and high-pressure steam. There are many kinds of medicines used for soaking, such as glutaraldehyde neutral solution. Soak the cleaned pipeline according to the specified ratio for 1-2 hours, and then wash it with clean water. It is suitable for metal, rubber and plastic. Ethylene oxide fumigation can penetrate rubber, plastic, etc., and is non-corrosive and non-destructive. However, it takes a week for ethylene oxide to volatilize after one disinfection. There are disadvantages such as long process, high price, and flammability, so it is not often used. . High-pressure steam sterilization is only suitable for metal and high-temperature resistant parts, and cannot be used for the disinfection of breathing tubes made of silica gel and other materials. Special attention should be paid to the fact that most of the exhaled flow sensors are made of platinum wire, which is dozens of times thinner than hair, and is easily damaged, and the price is also very expensive. The above method must not be used for disinfection, and it must be carried out according to the method introduced in the manual. The current ventilators are not satisfactory in terms of intelligence, automatic control capabilities, automatic monitoring and alarm functions, and safety. The rescue and treatment effects of ventilators on patients still depend on the level of operators. We expect that with the advancement of technology, there will be continuous emergence of intelligent ventilators with more complete functions, better performance and more convenient operation. In short, after strengthening the scientific management and use and maintenance of ventilators, blind introduction is basically avoided; the allocation and utilization of
ventilator resources are more reasonable; the responsibility for machine maintenance is clear; the failure rate of machines is greatly reduced; the economic and social benefits of machines are improved. significantly improved.
