(1) Airway obstruction or excessive secretion: the most common complication in mechanical ventilation, some data show that about 35%. Due to the airway is not smooth, ventilation is blocked, dyspnea occurs, causing man-machine confrontation. Zhang Wendong, Department of Respiratory Medicine, Lu'an Hospital of Traditional Chinese Medicine, Lu'an City
(2) bronchospasm: due to poor infection control, inadequate treatment to relieve airway spasm, so that airway resistance and respiratory work increased, the body lacks O2, resulting in respiratory muscle fatigue, respiratory movement is not coordinated, shallow and fast breathing, thus occurring man-machine confrontation.
(3) insufficient tidal volume: if the respiratory ventilation parameters are not set sufficiently, there may also be ventilator air leakage, especially in the normal operation of the ventilator occurs in the ventilator circuit pipeline implicit breakage leakage, it is more difficult to detect. In addition, under-inflation or broken leakage of the air sac on the tracheal tube not only reduces the ventilation of the lungs, but even causes secretions to seep into the airway, aggravating the obstruction and the occurrence of lack of O2.
(4) Persistent high fever, severe infection, or metabolic acidosis: Due to the increased consumption of the organism, metabolism accelerates, and the ventilation is not timely and correspondingly increased in the process of mechanical ventilation, resulting in a relative insufficiency of ventilation.
(5) single-lung ventilation: improper fixation of the tracheal tube, so that the catheter slides down to one side of the bronchus, the formation of single-lung ventilation, the opposite side of the lung atelectasis. This occurs in elderly patients with missing teeth and in whom transoral intubation is not easy to fix. One-lung ventilation results in a significant reduction in lung volume, airway hypertension, and dyspnea with human-machine confrontation.
(6) acute pulmonary edema: coronary heart disease cardiac insufficiency, heart failure can cause high pressure pulmonary edema, and organophosphorus poisoning, manifested as hyperosmotic pulmonary edema. Due to the pulmonary blood vessels and lung tissue fluid exchange function disorder, resulting in increased lung water content, causing pulmonary gas diffusion dysfunction, resulting in acute respiratory distress.
(7) Pneumothorax: a critical and serious complication of mechanical ventilation. Its occurrence is related to excessive tidal volume, high airway pressure, poor lung compliance of the patient and chronic lung lesions. Once pneumothorax is formed, the affected lung is compressed, airway pressure rises rapidly, and the clinical manifestations are severe man-machine confrontation and hypoO2emia.
Second, prevention and treatment strategies
Based on the causes of human-computer confrontation, the following measures should be taken:
(1) For patients with airway obstruction, firstly, the airway should be unblocked to relieve the obstruction, and airway management such as humidification and suction should be strengthened. For patients with high fever or large ventilation demand, humidification can be increased appropriately, and humidifying fluid can be injected into the trachea regularly if necessary to prevent dehydration of the airway, drying of secretions, and formation of sputum crusts. In addition to strengthening anti-infection and increasing the number of suction, patients with excessive secretions should pay attention to the presence of secretion regurgitation due to air sac problems, as well as avoiding catheter deformation and narrowing. In patients with bronchospasm, airway resistance should be relieved in a timely manner, and bronchodilators can be given using a gastric tube, or nebulized inhalation or intravenous medication. From the clinical therapeutic effect, the local use of β 2 agonist has the fastest effect, generally 5-15 min can make the bronchospasm get obvious relief. However, it must be carried out under the premise of adequate clearance of airway secretions, otherwise the efficacy of the drug is greatly reduced. In severe cases, pressure-controlled ventilation (PCV) can be used instead, and FiO2 can be increased appropriately.(2) If one-lung ventilation causes human-computer confrontation, the catheter can be retracted appropriately, and two-lung ventilation can be resumed. At the same time, the fixation of the catheter should be strengthened to maintain its proper position and depth to prevent the catheter from slipping into one side of the bronchus.
(3) insufficient tidal volume, manifested in the intubation of the immediate occurrence of man-machine confrontation, can directly increase the ventilator ventilation or respiratory rate, but also can use the respiratory balloon temporary hand-control assisted over-ventilation, when the blood O2 increased significantly and CO2 decreased, the patient's spontaneous respiration is weakened, and then connected to the respiratory machine can reduce the occurrence of man-machine confrontation. Repeatedly checking arterial blood gas can help to adjust the respiratory parameters.
(4) Persistent high fever, severe infection, metabolic acidosis, etc., need to appropriately increase ventilation. If insufficient ventilation occurs without the above reasons, we should be alert to the possibility of ventilator leakage, the most common is the hidden breakage of ventilator hose leakage, once confirmed, the hose should be replaced immediately.
(5) Complicated pneumothorax. When the condition is critical, direct puncture exhaust, closed drainage, prompting lung reopening.
(6) Mechanical ventilation should be emphasized to strengthen the treatment of coronary heart failure of the primary disease. Cardiac insufficiency should control the total amount of rehydration fluid and drip rate, to prevent the occurrence of medical pulmonary edema. Therefore, if hypoxia is not improved after strengthening the treatment of the primary pathology and causative factors, PEEP can be considered to increase end-expiratory alveolar pressure, reduce intrapulmonary shunting, increase alveolar gas exchange and reduce alveolar and interstitial tissue edema.
(7) Neurologically excited or just intubated on the machine patients, due to negative pressure during inhalation to start the ventilator, there is a sense of resistance during exhalation, unlike normal breathing, a momentary use of the ventilator is not adapted to the use of the machine, can be used for a short period of time to reduce the use of sedatives, to reduce the human-computer confrontation. Only in the case of exclusion of the occurrence of man-machine confrontation fatal cause, such as the above disposal, breathing is still not synchronized, can consider the use of muscle relaxation drugs, eliminating the patient's voluntary respiration, the use of artificial mechanical control of respiration, so as to improve the efficiency of its ventilation.