A ventilator is a device that can replace, control or change a person's normal physiological breathing, increase lung ventilation, improve respiratory function, reduce respiratory work consumption, and save heart reserve capacity. When infants and young children have acute respiratory failure, active conservative treatment is ineffective, the breathing is weakened, the sputum is thick and thick, the expectoration is difficult, the airway is blocked or the atelectasis occurs, tracheal intubation and ventilator should be considered.
The ventilator must have four basic functions, namely, inflating the lungs, converting inhalation to exhalation, expelling alveolar air, and exhaling to inhaling, in turn, cyclically. Therefore, it must have: (1) It can provide the power to transport the gas to replace the work of the human respiratory muscles; (2) It can produce a certain respiratory rhythm, including the respiratory frequency and the ratio of inhalation to expiration, to replace the function of the human respiratory central nerve innervating the respiratory rhythm; Appropriate tidal volume (VT) or minute ventilation (MV) to meet the needs of respiratory metabolism; ⑷The gas supplied is best to be heated and humidified to replace the function of the human nasal cavity, and can supply higher than that contained in the atmosphere. The amount of O2 to increase the concentration of inhaled O2 and improve oxygenation. Power source: Compressed gas can be used as power (pneumatic) or motor as power (electric). Respiration frequency and inspiratory-expiration ratio can also be used pneumatic pneumatic control, electric electric control, pneumatic electric control, etc., switching between exhalation and inhalation, often Switch to exhalation (constant pressure type) after reaching a predetermined pressure in the breathing loop during inhalation, or switch to exhalation (constant volume type) after reaching a predetermined volume during inhalation, but modern ventilators have both of the above form.
Ventilators for treatment are often used for patients with more complex and severe illnesses. They require complete functions and can perform various breathing modes to meet the needs of changing conditions. Anesthesia ventilator is mainly used for patients undergoing anesthesia surgery. Most patients have no major cardiopulmonary abnormalities. As long as the required ventilator can perform IPPV with variable ventilation, respiratory rate and breathing rate, it can basically be used.
