If air enters the blood vessels, the amount of air entered needs to be strictly observed; if the amount of air entered is within 1 ml, there is usually no significant vascular response. If the amount of air entered is within 1-5 ml, the patient’s heart rate, blood pressure, pulse, and oxygen saturation must be closely observed. If the amount of air entered is within 5-20ml, there will be obvious vascular reaction, at this time there will be vasospasm, facial color cyanosis, lack of oxygen, palpitation, chest tightness and shortness of breath, serious tachycardia or cardiac arrhythmia, and sudden dizziness, sudden collapse, and in severe cases, there will be apnea. If the incoming air is greater than 20 ml or more, air embolism is particularly likely to occur, and severe lethal shock and other vascular reactions may occur.