Ventilator block diagram Medical Positive Pressure Breathing Machine Positive Pressure Breathing Machine,Continuous Positive Pressure Ventilation,Intermittent Positive Pressure Ventilation,Intermittent Positive Pressure Breathing Machine Guangzhou Zhongzhinan Supply Chain Co.,Ltd. , https://www.gzzhongzhinan.com
1. Grafting work site. Grafting is a meticulous task for surgery on small seedlings and requires a suitable environment. The most suitable environmental conditions for grafting are direct exposure to sunlight, low contact with outside air, temperatures in the range of 20-24 degrees, and relative humidity of more than 80%. Generally, they need to be carried out in greenhouses and greenhouses.
2. The grafting blade needs to be sharp. The razor used for grafting must be sharp. When the blade starts to blunt, the incision is not smooth and smooth, which has an impact on survival. Therefore, the blade cannot be ignored. Taking grafted watermelon as an example, it is advisable to graft 200 pieces on each side.
3. Remove the diseased seedlings. The instruments used in grafting and the hands of the operators are liable to spread diseases. Grafting a diseased seedling, all the cutting tools and hands that have contacted the diseased seedling may be infected with germs, and the disease will be brought to the grafted seedling. Therefore, it is very important to pay attention to finding and removing diseased seedlings before grafting.
4. Prevent bacteria from infecting scion. Grafting can only expect germs not to invade from roots of rootstocks, and it is unrealistic to borrow rootstocks to enhance scion resistance. Therefore, we must pay attention to prevent the direct infection of the scion. (1) Strictly prevent spontaneous rooting of scion. When cutting off the root of the scion after grafting, the position should be as high as possible and the incision must be smooth. After the survival of the transplanted seedlings, it should be noted that the self-producing roots of the scions that have occurred in the center pith of the rootstock are immediately removed or discarded after discovery; (2) The grafting site must be kept clean and free from staining during grafting and grafting. Sheung Shui or mud. After contact with soil or water, it is highly susceptible to contamination, infection of pathogens, and spontaneous rooting of scions is also easily induced. Therefore, special attention should be paid when grafting; (3) Grafting seedlings should not be planted too deeply, and should be paid attention to when soils are cultivated; (4) Crossing of infectious germs should be avoided when preventing pruning, topping and other field operations.
5. Avoid over-contiguous work and take various measures to prevent disease. Although rootstocks have disease resistance, most stocks have no ability to avoid pests and diseases. Therefore, even if the disease-resistant rootstock is cultivated at the time of cultivation, the disease may be caused by excessive density of the bacteria or poor soil environmental conditions. Therefore, it is very important to avoid excessive continuous cropping and adopt various cultivation and disease prevention measures so that the density of bacteria is not too high and the soil environment is deteriorated.
6. Pay attention to the management of fertilizer and water for grafting seedlings.
7. Pay attention to the prevention of new diseases in grafted nursery cultivation. After grafting and raising seedlings, due to changes in plant resistance, or due to the generation of wounds, some diseases that may not have become major diseases in the past may develop into dominant diseases.
One. Main mechanical ventilation modes
(1) Intermittent Positive Pressure Ventilation (IPPV): positive pressure in the inspiratory phase and zero pressure in the expiratory phase. 1. Working principle: The ventilator generates positive pressure in the inspiratory phase and presses the gas into the lungs. After the pressure rises to a certain level or the inhaled volume reaches a certain level, the ventilator stops supplying air, the exhalation valve opens, and the patient's thorax Passive collapse of the lungs and exhalation. 2. Clinical application: Various patients with respiratory failure mainly based on ventilation function, such as COPD.
(2) Intermittent positive and negative pressure ventilation (IPNPV): the inspiratory phase is positive pressure and the expiratory phase is negative pressure. 1. How it works: The ventilator works both in the inspiratory and exhaled phases. 2. Clinical application: Expiratory negative pressure can cause alveolar collapse and cause iatrogenic atelectasis.
(3) Continuous positive pressure airway ventilation (CPAP): Refers to the patient's spontaneous breathing and artificial positive airway pressure during the entire respiratory cycle. 1. Working principle: Inspiratory phase gives continuous positive pressure air flow, and exhalation phase also gives a certain resistance, so that the airway pressure of inhalation and exhalation phases are higher than atmospheric pressure. 2. Advantages: The continuous positive pressure airflow during inhalation is greater than the inspiratory airflow, which saves the patient's inhalation effort, increases FRC, and prevents the collapse of the airway and alveoli. Can be used for exercise before going offline. 3. Disadvantages: great interference to circulation, large pressure injury of lung tissue.
(4) Intermittent command ventilation and synchronized intermittent command ventilation (IMV / SIMV) IMV: There is no synchronization device, the ventilator air supply does not require the patient's spontaneous breathing trigger, and the time of each air supply in the breathing cycle is not constant. 2. SIMV: There is a synchronization device. The ventilator gives the patient a commanded breath according to the pre-designed breathing parameters every minute. The patient can breathe spontaneously without being affected by the ventilator. 3. Advantages: It exerts its ability to regulate breathing while offline; it has less influence on circulation and lungs than IPPV; it reduces the use of shock medicine to a certain extent. 4. Application: It is generally considered to be used when off-line. When R <5 times / min, it still maintains a good oxygenation state. You can consider off-line. Generally, PSV is added to avoid respiratory muscle fatigue.
(5) Mandatory ventilation per minute (MMV) When spontaneous breathing> preset minute ventilation, the ventilator does not command ventilation, but only provides a continuous positive pressure. 2. When spontaneous breathing is less than the preset minute ventilation volume, the ventilator performs command ventilation to increase the minute ventilation volume to reach the preset level.
(6) Pressure Support Ventilation (PSV) Definition: Under the prerequisite of spontaneous breathing, each inhalation receives a certain level of pressure support, increasing the patient's inhalation depth and inhalation volume. 2. How it works: The inspiratory pressure begins with the patient's inspiratory action, and ends when the inspiratory flow rate decreases to a certain level or the patient attempts to exhale hard. Compared with IPPV, the pressure it supports is constant, and it is adjusted by the feedback of the inspiratory flow rate. Compared with SIMV, it can get pressure support for each inhalation, but the level of support can be set according to different needs. 3. Application: SIMV + PSV: used for preparation before off-line, can reduce breathing work and oxygen consumption Indications: Exercise the ventilator; prepare before going offline; the ventilator is weak due to various reasons; severe flail chest causes abnormal breathing. 5. Note: Generally not used alone, it will produce insufficient or excessive ventilation.
(7) Volume Supported Ventilation (VSV): Each breath is triggered by the patient's spontaneous breathing. The patient can also breathe without any support and can reach the expected TV and MV levels. The ventilator will allow the patient to be truly autonomous Breathing also applies to preparations before going offline.
(8) Capacity control of pressure regulation
(IX) Biphasic or bilevel positive pressure ventilation How it works: P1 is equivalent to inspiratory pressure, P2 is equivalent to breathing pressure, T1 is equivalent to inspiratory time, and T2 is equivalent to exhalation time. 2. Clinical application: (1) When P1 = inspiratory pressure, T1 = inspiratory time, P2 = 0 or PEEP, T2 = expiratory time, which is equivalent to IPPV. (2) When P1 = PEEP, T1 = infinity, P2 = 0, T2 = O, which is equivalent to CPAP. (3) When P1 = inspiratory pressure, T1 = inspiratory time, P2-0 or PEEP, T2 = desired controlled inhalation cycle, equivalent to SIMV.
Grafting precautions
Grafting and seedling is the combination of scion and rootstock to form a complete plant. Therefore, joints must be completely healed, the appearance of the plant body is complete, the internal tissues are tightly connected, the organs are connected well, and the water transport of nutrients is not impeded. To achieve a high graft survival rate, good grafting quality, and the size of the scion, rootstock age, incision shape and grafting time, and proper management after grafting have a great relationship. Grafting cultivation should pay attention to the following issues: