contents
introduction
working process
ventilator classification
ventilation mode
working parameters
blood gas analysis
humidification problem
indications
indications
contraindications
disinfection methods
use methods of non-invasive ventilators
Indications for use
Indications, contraindications, disinfection methods, usage methods of non-invasive ventilator Treatment and nursing of non-invasive ventilator Start editing Introduction to this paragraph
Ventilator
"Ventilator"-this term was created by Sullivan! -Professor Sullivan, inventor of the world's first sleep ventilator, the ventilator is a device that can replace, control or change people's normal physiological breathing, increase lung ventilation, improve respiratory function, reduce respiratory work consumption and save heart reserve capacity. When infants and young children are complicated with acute respiratory failure, after active conservative treatment is ineffective, breathing is weakened, sputum is thick and thick, sputum is difficult to be discharged, airway is blocked or atelectasis occurs, tracheal intubation and ventilator should be considered. The ventilator must have four basic functions, namely, inflating the lungs, converting inspiratory to expiratory, expelling alveolar gas and converting expiratory to inspiratory, and so on. Therefore, there must be: (1) it can provide the power to transport gas and replace the work of human respiratory muscles; ⑵ It can produce certain respiratory rhythm, including respiratory frequency and inspiratory-respiratory ratio, to replace the function of human respiratory central nerve to control respiratory rhythm; ⑶ Appropriate tidal volume (VT) or minute ventilation volume (MV) can be provided to meet the needs of respiratory metabolism; (4) The supplied gas should be heated and humidified to replace the function of human nasal cavity, and it can supply more O2 than that contained in the atmosphere, so as to increase the inhaled O2 concentration and improve oxygenation. Power source: compressed gas can be used as power (pneumatic) or motor can be used as power (electric). Breathing frequency and inspiratory-expiratory ratio can also be switched by pneumatic pneumatic control, electric control, pneumatic control, etc. Breathing and inspiratory phases are often switched to exhalation (constant pressure type) after reaching a predetermined pressure in the breathing circuit during inhalation or to exhalation (constant volume type) after reaching a predetermined volume during inhalation, but modern ventilators have both of the above types. Therapeutic ventilators are often used for patients with complicated and severe conditions, which require complete functions and can carry out various breathing modes to meet the needs of changing conditions. Anesthetic ventilators are mainly used in patients undergoing anesthesia surgery, and most patients have no major cardiopulmonary abnormalities. The required ventilators can be basically used as long as they can change the volume, breathing frequency and inspiratory-respiratory ratio and can do IPPV.
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The pressure of the patient gas injected by the ventilator
is generated by the internal turbopump. Engineering process: the air enters the emergency valve through the filter, the opening size of the emergency valve and the rotating speed of the pump are controlled by the CPU, the pressure and capacity of ventilation are set by the doctor according to the needs of SARS patients, and an appropriate amount of gas is adjusted to enter the human face mask through the one-way valve and breathe into the human body, that is, positive pressure is inhaled; When the one-way valve is turned down, the inhalation pressure decreases, and the positive inhalation pressure in the patient's lungs automatically flows out, that is, exhales through the mask. The pressure of the gas injected into the patient, the oxygen pressure of the oxygen cylinder and the positive pressure air are generated. Working process: medical oxygen is mixed with the air passing through the filter through the pressure reducing valve and enters the gas storage tank. The flow regulator is controlled by CPU. The pressure and capacity of ventilation are set by doctors according to the needs of SARS patients, and an appropriate amount of gas is adjusted to enter the human face mask through the one-way valve, which is positive inspiratory pressure. When the patient exhales, the one-way valve is turned down, the inspiratory pressure is reduced, and the positive inspiratory pressure in the patient's lungs automatically flows out. That is to say, exhale through the mask
edit the ventilator classification in this paragraph
1. According to the connection mode with the patient, it is divided into: non-invasive ventilator: ventilator is connected with the patient through the mask; invasive ventilator: ventilator is connected with the patient through tracheal intubation; 2. Classification by use (six categories): ventilator
Emergency ventilator: dedicated to on-site first aid. N Respiratory therapy ventilator: provide long-term ventilation support and respiratory therapy for patients with respiratory insufficiency. N Anesthesia ventilator: it is specially used for anesthesia breathing management. N Pediatric ventilator: it is specially used for ventilation support and respiratory therapy for children and newborns. N high-frequency ventilator: it has the function of ventilation frequency > 6 times /min. N non-invasive ventilator: complete ventilation support through mask or nasal mask. N 3, classified by driving mode (three categories): pneumatic controlled ventilator: the ventilation source and control system only use oxygen as the power source. Most of them are portable emergency ventilators. Electrically controlled ventilator: The ventilation source and control system are powered by power supply, and there are cylinders, piston pumps, etc. inside, so it is a ventilator with simple functions. Pneumatic electronic control ventilator: the ventilation source is powered by oxygen, and the control system is powered by power supply. Mainstream design of multifunctional ventilator. 4. Classification by ventilation mode (four categories): timing ventilator (time switching): complete the conversion of exhalation and inhalation according to the preset time. N Constant volume ventilator (capacity switching): complete the conversion between exhalation and inhalation according to the preset output air volume. N Constant pressure ventilator (pressure switching): complete the conversion between exhalation and inhalation according to the preset airway pressure value. N constant flow ventilator (flow rate switching): complete the conversion between exhalation and inhalation according to the preset gas flow rate value. N 5, according to the classification of pressure and flow generators (four categories): Mapleson(1959) Constant pressure generator: the ventilation source is driven low, the inspiratory period is constant pressure, and the inspiratory flow changes with the intrapulmonary pressure. N Non-constant pressure generator: the ventilation source is driven low, which changes regularly during inspiratory period, and the inspiratory flow is affected by both driving pressure and intrapulmonary pressure. N constant current generator: the ventilation source drives the high pressure, and the air flow is constant during the inspiratory period. N Non-constant current generator: The ventilation source drives the high pressure, and the airflow changes regularly during the inspiratory period. N Pressure generator is suitable for patients with normal lung function, and flow generator is suitable for patients with poor lung compliance. N
edit the ventilation mode in this section
ventilator
1. Intermittent positive pressure ventilation (IPPV): the most basic ventilation mode. When inhaling, positive pressure is generated, which presses the gas into the lungs, and the body exhales the gas by its own pressure. 2. Exhale platform: also called end inspiratory positive pressure breathing (EIppb). At the end of inhalation and before exhalation, the expiratory valve will continue to be closed for a period of time before exhalation, which generally does not exceed 5% of the breathing cycle. Can reduce VD/VT (Dead Space/Tidal Volume) 3. Positive end expiratory pressure (PEEP): On the premise of intermittent positive pressure ventilation, keeping a certain pressure in the end expiratory airway plays an important role in the treatment of respiratory distress syndrome, non-cardiogenic pulmonary edema and pulmonary hemorrhage. 4. Intermittent mandatory ventilation (IMV) and synchronous intermittent mandatory ventilation (SIMV): they belong to the auxiliary ventilation mode, and there is continuous airflow in the ventilator pipeline. (Breathing and inhaling spontaneously) Give a positive pressure ventilation after several spontaneous breaths to ensure the ventilation volume per minute. The breathing frequency of IMV is generally less than 1 breaths/minute for adults and 1/2~1/1 5 for children. Expiratory delay, also called expiratory delay: it is mainly used for early airway collapse and chronic obstructive pulmonary diseases, such as asthma, and should not be used for too long. 6. Take a deep breath or sigh 7. pressure support: On the basis of spontaneous breathing, provide certain pressure support, so that the pressure can reach the predetermined peak pressure value every time you breathe. 8. Continuous positive airway pressure (CPAP): In addition to adjusting the CPAP knob, it is necessary to ensure sufficient flow, which should be increased by 3~4 times. The normal value of CPAP is generally 4~12cm water column, and it can reach 15 cm water column under special circumstances. (Exhale pressure 4 cm water column).
edit the working parameters of this paragraph
ventilator
four parameters: tidal volume, pressure, flow rate and time (including respiratory frequency and inspiratory-expiratory ratio). 1. Tidal volume: The tidal output must be greater than the human physiological tidal volume, which is 6-1 ml/kg, while the tidal output of the ventilator can reach 1-15 ml/kg, which is often 1-2 times of the physiological tidal volume. It should be further adjusted according to chest fluctuation, auscultation of air intake in both lungs, reference pressure table and blood gas analysis. 2. Breathing frequency: close to the physiological breathing frequency. 4-5 beats per minute for newborns, 3-4 beats per minute for infants, 2-3 beats per minute for older children and 16-2 beats per minute for adults. Tidal volume * respiratory rate = ventilation per minute 3. Inhalation-respiration ratio: generally 1: 1.5-2, the expiratory time can be adjusted to 1: 3 or longer for obstructive ventilation disorder and 1: 1 for restrictive ventilation disorder. 4. Pressure: generally refers to the peak airway pressure (PIP). When the lung compliance is normal, the peak inspiratory pressure is generally 1-2 cm water column, and the lung lesions are mild: 2-25 cm water column; Medium: 25-3 cm water column; Severity: more than 3 cm water column, RDS and pulmonary hemorrhage can reach more than 6 cm water column. But generally below 3, the newborn is 5 cm lower than the above pressure. 5. PEEP It is in line with physiological conditions for children who use IPPV to give PEEP2-3 cm water column. When severe ventilation disorders (RDS, pulmonary edema, pulmonary hemorrhage) occur, PEEP should be increased, usually at 4-1 cm water column, and in severe cases, it can reach 15 or even 2 cm water column. When the oxygen concentration exceeds 6% (FiO2 is greater than .6), if the arterial oxygen partial pressure is still below 8mm Hg, PEEP should be mainly increased until the arterial oxygen partial pressure exceeds 8mm Hg. Every time PEEP increases or decreases 1~2 mm water column, it will have a great impact on blood oxygen, which can appear within a few minutes. It is necessary to reduce PEEP gradually and pay attention to monitoring the changes of blood oxygen. PEEP value can be read from the end-expiratory position of the pointer of the pressure meter. 6. Flow rate: at least twice the ventilation volume per minute, generally 4-1 liters/minute
Edit this paragraph of blood gas analysis
Ventilator
First, check whether the respiratory tract is unobstructed, the position of tracheal catheter, the air intake of both lungs is good, whether the ventilator delivers air normally and whether there is air leakage. 1. When PAO _ 2 is too low: (1) increase the oxygen concentration; (2) increase the PEEP value; (3) If ventilation is insufficient, the ventilation rate per minute can be increased, the inspiratory time can be prolonged, and the end of inspiratory stay can be prolonged. 2. When PAO _ 2 is too high: (1) reduce the oxygen concentration; (2) gradually reduce the PEEP value. 3. When PaCO 2 is too high: (1) increase the breathing frequency; (2) increase the tidal volume: constant volume type can be directly adjusted, constant pressure type can increase the preset pressure, and timing type can increase the flow rate and increase the pressure limit. 4. When PaCO 2 is too low: (1) Slow down the breathing frequency. The expiratory and inspiratory time can be prolonged at the same time, but the expiratory time should be mainly prolonged, otherwise it will have the opposite effect. If necessary, it can be changed to IMV mode. (2) Reduce tidal volume: constant volume type can be directly adjusted, constant pressure type can reduce preset pressure, and timing type can reduce flow and pressure limit.
Edit the humidification problem in this paragraph
Breathing machine
Heating humidification: the best effect is achieved, the water temperature in the tank is 5-7 degrees Celsius, the standard pipe length is 1.25m, the gas temperature at the outlet is 3-35 degrees Celsius, and the humidity is 98- 99%. The wetting liquid can only be distilled water. Atomizer: low temperature and great irritation. It is more difficult for patients to accept. Direct intratracheal instillation: especially when there is sputum scab obstruction in the airway, repeated back slapping and sputum suction after instillation can often relieve poor ventilation. Specific methods: Adults drop 2 ml of .45-.9 saline every 2-4 minutes, or at a rate of 4-6 drops/minute, with a total amount of more than 2 ml/day, and children drop 3-1 drops every 2-3 minutes, with thin airway secretions, smooth suction and no sputum scab. Artificial nose. Slightly. Oxygen absorption concentration (FiO2): Generally, the oxygen concentration of machines can be adjusted from 21% to 1%. It is necessary to correct hypoxemia and prevent oxygen poisoning. Generally, it should not exceed .5~.6. If it exceeds .6, the time should be less than 24 hours. Objective: To make PaO2 _ 2 in arterial blood greater than 6 mm Hg (8.Kpa) with the lowest oxygen concentration. PEEP can be added if cyanosis cannot be relieved after oxygen is given. 1. oxygen can be used during resuscitation, regardless of oxygen poisoning. Set alarm range: upper and lower limit alarm of airway pressure (generally 3% of the set value), air source pressure alarm and other alarms. Unexpected problem: there should be a resuscitator or other simple artificial airbag beside the ventilator, and the joint between the airbag and the endotracheal tube should also be prepared. Pay attention to prevent tube detachment, tube blockage, ventilator failure, gas source and power supply failure. Common complications: pressure injury, circulatory disorder, respiratory infection, atelectasis, laryngeal and tracheal injury. Evacuation of ventilator: gradually reduce the oxygen concentration, PEEP to 3~4 cm water column, change IPPV to IMV (or SIMV) or pressure support, gradually reduce IMV or support pressure, and finally transition to CPAP or completely evacuate the ventilator. The whole process requires close observation of breathing and blood gas analysis. Indications of extubation: spontaneous breathing and cough are strong, swallowing function is good, blood gas analysis results are basically normal, and there is no laryngeal obstruction, so extubation can be considered. Tracheal intubation can be pulled out at one time, and tracheostomy can be pulled out gradually by changing the thin tube, half blocking the tube and completely blocking the tube.
Edit the indications in this paragraph
The physiological effects of mechanical ventilation, that is, (1) improving ventilation, (2) improving ventilation and (3) reducing respiratory power consumption, determine that mechanical ventilation can be used to improve the following pathological and physiological states. Ventilation pump failure: decreased impulse delivery and conduction disorder in respiratory center; Mechanical dysfunction of thoracic cavity; Respiratory muscle fatigue. Ventilation dysfunction: decreased functional residual volume; V/Q ratio imbalance; Increased pulmonary shunt; Diffuse disorder. It is necessary to strengthen airway managers: keep airway unobstructed and prevent suffocation.