How does the atomization treatment that our hospital often says operate? Please give a detailed answer, thank you!

Atomization inhalation therapy mainly refers to atomization inhalation therapy. Aerosol refers to tiny solid or liquid particles suspended in the air. Therefore, atomization inhalation therapy is to disperse drugs (solution or powder) into tiny droplets or particles through atomization device, so that they can be suspended in gas and enter the respiratory tract and lungs, thus achieving the purposes of cleaning the airway, reforming the airway, local treatment (spasmolysis, anti-inflammation, expectoration) and systemic treatment. -pathophysiological basis of atomization therapy

(1) Humidification and heating of inhaled gas

In order to maintain the normal physiological function of the mucus-ciliary system of the respiratory tract, the human respiratory tract must be in a state of saturated temperature and humidity (that is, at 37? C, the humidity in the airway is 100%, which is 44mg/L). Affect the humidification and heating of respiratory tract: ① Inhale cold and dry gas; ② High fever. ③ overpass. (4) When breathing by mouth or establishing artificial airway. ⑤ Respiratory diseases.

(B) the impact of inhalation of humid gases on the respiratory system

1. Insufficient humidification of inhaled gas.

(1) damages the mucociliary system.

(2) Decreased lung function

(3) causing respiratory inflammation

2. Inhaled gas humidity is too high.

(1) Mucus-cilia system is damaged, over-hydrated, cilia movement function is weakened, and the arrangement is disordered.

(2) Lung function decreased, ventilation function was impaired, alveolar arterial oxygen partial pressure difference increased, PaO2↓, lung compliance decreased.

(3) causing water poisoning and pulmonary edema (attention should be paid to cardiac and renal insufficiency and children).

(3) atomization treatment of local lesions

(d) Atomizing inhalation to treat extrapulmonary diseases, such as ergotamine tartrate to treat migraine.

Second, the factors affecting the deposition and function of fog particles in the respiratory system

Maintaining the stability of water droplets is the premise of atomization treatment, and the main factors affecting its stability are the volume and properties of (1) water droplets. (2) the concentration of particles. (3) air humidity. Stable conditions: the diameter is 0.3-0.7um, the concentration is 100- 1000/L, and the diameter of general atomizer is 0.5-3um.

(A) the nature of fog particles

The physical mechanism leading to fog particle deposition is:

(1) impact deposition. (2) Gravity deposition. (3) Dispersive deposition. (4) Interception of sediment deposition. (5) Electrostatic attraction deposition

Relationship between fog particle diameter and deposition position

Particle volume (diameter)

Depositional site

Main sedimentary methods

& gt 10

Oral cavity (chest)

Impact deposition

5- 10

Trachea and 2 tracheal trees (trachea and trachea area)

Impact deposition

1- 10

Bronchus-bronchiole

Impact+gravity deposition

1-5

bronchiole

Gravity deposition

≤3

Respiratory bronchioles, alveoli (lung area)

Gravity deposition

0.25-0.5

Respiratory bronchioles, alveoli (lung area)

Stable, rare

& lt0.25

pulmonary alveolus

Dispersed deposition

(2) the type of breathing

The amount of droplets deposited in the lung is positively correlated with the volume of inhaled gas and negatively correlated with the ventilation frequency. The ideal breathing form is to inhale slowly and deeply from the functional residual vent (0.5L/ s), hold your breath for about 5- 10S at the end of inhalation, and then exhale quickly.

(3) Speed (flow rate) of fog particle release

The droplet velocity released by jet atomizer and ultrasonic atomizer is basically the same.

(4) the pathophysiological state of the patient's respiratory tract

(5) Pharmacokinetic factors of aerosol.

Pharmacokinetics of inhaled drugs plays an important role in aerosol inhalation therapy. If the purpose of atomizing inhalation is that drugs have therapeutic effect in the local lung, drugs with high local biological activity (such as corticosteroids) that are inhaled into the airway but quickly inactivated when absorbed throughout the body should be selected. If drugs only act on other parts of the body through airway absorption, drugs with better respiratory mucosa absorption and lower local metabolic rate should be selected.

(6) Atomizing inhalation auxiliary device

For patients receiving artificial airway mechanical ventilation, placing the atomization generator 30cm away from the patient's endotracheal tube can increase the deposition rate of aerosol in the lungs, because the ventilator air supply tube acts as a fog separator for gathering aerosol particles.

Three aerosol generating devices

(1) atomizer

1 Small capacity atomizer (SVN) is also called jet atomizer, manual atomizer, medical atomizer or wet atomizer. At present, it is the most commonly used aerosol generator in clinic. Working principle: compressed air or oxygen (driving force) passes through a narrow nozzle at high speed. According to the Venturi effect, negative pressure is generated around the nozzle, and the liquid medicine in the liquid storage tank is brought into the high-speed airflow and crushed into droplets with different sizes, of which more than 99% are composed of large droplets. The remaining fine droplets fall back to the liquid storage tank through the interception and collision of the nozzle and are ejected at a certain speed, and the smashed particles are re-atomized. Clinical application of jet atomizer can treat bronchodilators, hormones, antiallergic drugs and antibiotics by atomizing inhalation. Generally, the driving gas flow rate of the spray atomizer is 6L/min-8L/min, and the liquid medicine in the liquid storage tank is 4ml-6ml. For the solution with high atomization viscosity, the driving gas flow rate can be increased, but the maximum gas flow rate does not exceed 12L/min. Usage: ① Put the medicine to be inhaled into the liquid storage tank; ② Dilute the medicine in the liquid storage tank to 4 ml-6 ml; ③ Adjust the gas flow (generally 8 l/min); (4) connecting the nozzle and the mask with the patient; ⑤ Patients are required to breathe slowly (normal tidal volume) and take deep breaths at regular intervals until the total lung volume reaches 4 s-10s; ⑥ The continuous atomization time is about 65438±05min；; ⑦ Observe the effect and side effects of patients after atomizing inhalation.

The working principle of ultrasonic atomizer is to convert electric energy into high-frequency vibration of ultrasonic thin plate, and high-frequency vibration converts liquid medicine into aerosol particles. The size of fog particles produced by ultrasonic atomizer is inversely proportional to the ultrasonic vibration frequency: the higher the vibration frequency, the smaller the aerosol particles; On the contrary, the intensity of ultrasonic vibration is directly proportional to the number of aerosol particles: that is, the stronger the vibration, the more aerosol particles are produced and the greater the density. The particle size of aerosol produced by ultrasonic atomizer is 3.7um-10.5um. It should be noted that patients with hypoxia or hypoxemia should use it with caution or not for a long time, because the aerosol produced by ultrasonic atomizer has a high density and the oxygen partial pressure in the airway is relatively high after inhalation.

(1) metered-dose inhaler

MDIs is the most widely used aerosol generator at present. It has the advantages of quantification, simple operation, portability, convenient use, no need for regular disinfection and no cross infection in hospital, so it is widely welcomed.

1. working principle: the sealed medicine storage tank is filled with medicine and booster (usually freon). The medicine is dissolved or suspended in the liquid booster, and the liquid medicine can be communicated with the quantitative chamber through the quantitative valve and then sprayed out through the nozzle. After encountering atmospheric pressure, the propellant is rapidly ejected due to sudden evaporation, and the liquid medicine is taken out and atomized into aerosol particles. The diameter of aerosol particles produced by MDIs is about 3 μ m-6 μ m.

2. Correct usage: shake the liquid medicine evenly before each use. The patient exhaled deeply to the level of residual gas, opened his mouth, placed the MDIs nozzle 4cm in front of his mouth, and slowly inhaled (0.5L/s) to almost the whole lung volume level. At the beginning of inhalation, press your fingers to spray medicine, hold your breath for 5s- 10s at the end of inhalation, and then exhale slowly to the level of functional residual gas. You can use it again after a rest of about 3 minutes. This method is suitable for all patients who inhale any medicine except infants.

3. The dedicated MDIs MDIs can improve the inhalation effect of aerosol atomization with the help of fog storage device, because the application of fog storage device can reduce the initial velocity of aerosol sprayed by MDIs, increase the distance between MDIs nozzle and oral cavity, and reduce the sedimentation of aerosol particles in oral cavity; The biggest advantage of connecting MDIs with fog storage device is that patients don't need the coordinated action of spraying medicine and inhaling. It can be used for patients who are difficult to master the routine use of MDIs or children and infants who cannot cooperate. But it is bulky and inconvenient to carry.

(2) Dry powder inhaler

1. Single-dose inhalers are usually rotary or rotary inhalers, with a sharp needle on the rotary disk and dry powder inhaled into capsules. When in use, the drug capsule is first put into the adsorber, and then gently rotated to make the turntable and the needle on the turntable smash the capsule; The patient can inhale deeply through the catheter in the mouth, thus driving the spiral blade in the absorber to rotate and stirring the dry powder of medicine to make it into aerosol particles for inhalation. The sedimentation rate of atomized particles in the lungs of single-dose inhalers is about 5%-6%, which is rarely used. It is often used to inhale sodium crotonate dry powder to prevent allergic asthma in children.

2. Multi-dose disc inhalers usually include Dubao and disc inhalers. Inhaled dry powder is packed in capsules. Multiple doses can be filled into the inhaler at one time. When in use, rotate the shell or push and pull the sliding disc, and transfer one dose at a time. The patient pulls up the cover shell connected with it in a tit-for-tat manner, and pierces the capsule containing the powder, that is, the suction nozzle with the inhaler in its mouth deeply sucks the powder in, inhales it for 5s- 10s, and then exhales it slowly. The multi-dose inhaler can be reused, and the inhaled aerosol particles are pure powder, which does not contain flux and surfactant. The operation method is simple and easy to carry, so it is welcomed by patients and meets the requirements of environmental protection. The biggest advantage of multi-dose inhaler is that the inhalation of powder is driven by the patient's breathing, and there is no need for coordinated action of deliberate breathing and hand pressure. The disadvantage is that it may be restricted for patients with chronic obstructive pulmonary disease with decreased respiratory muscle strength, patients with severe asthma attack, infants with weak respiratory muscle strength and younger children.

Jet atomizer. Advantages and disadvantages of metered dose inhalers and dry powder inhalers;

Small dose atomizer (SVN)

Large doses can be administered continuously or repeatedly; The patient's need for coordinated breathing is reduced; Freon is not needed as a booster.

Atomizers are easy to be polluted, leading to cross and nosocomial infection; Expensive; Serious waste of inhaled drugs; There are certain choices for inhaling drugs; Need high-pressure airflow as power; The treatment time is longer.

Metered inhaler

Convenient. The price is lower.

Need patients to coordinate breathing movements; Aerosol deposited more in oropharynx; It is difficult to deliver large doses of drugs; There are certain choices of drugs; Patients may be abused; Freon is used as a booster.

MDIs fog storage device

The demand for patient's respiratory coordination is reduced; Aerosol deposition in oropharynx is less; Increase the curative effect of atomized inhalation.

The fog storage device is inconvenient to carry; Compared with using metered-dose inhalers alone, it increases the cost.

Dry powder inhaler

The demand for patient's respiratory coordination is reduced; The patient breathes and starts spraying medicine; Freon is not needed as a booster.

A higher inspiratory airflow is required; Drugs have certain selectivity; Can not be used for patients with mechanical ventilation; It is difficult to deliver large doses of drugs.

Clinical application of atomized inhalation therapy

Respiratory tract obstructive disease

Atomized inhalation therapy can be used to prevent and treat airway obstructive diseases. Among them, inhaled corticosteroids and antiallergic drugs are the main preventive drugs; Inhalation of β -adrenergic agonists and anticholinergic bronchodilators is only necessary during treatment. Aerosol therapy for airway obstructive diseases

Drug name

Receptor interacting with airway and its action time

Dosage of medicine (mg) and its usage