Blood gas analyses are routinely performed in patients with bronchial asthma after admission to the hospital. If the patient has significant wheezing symptoms, hypoxemia or respiratory failure may be evident. If there is a combination of type II respiratory failure, the results of blood gas analysis often indicate the presence of carbon dioxide retention. So for patients with bronchial asthma, through blood gas analysis can determine whether the patient needs oxygen or use a ventilator, especially for patients with severe asthma, often the patient’s blood gas analysis results of the partial pressure of oxygen is very low, the partial pressure of carbon dioxide is relatively high, which often requires mechanical ventilation to relieve the patient’s clinical symptoms, so the blood gas analysis of the patient with bronchial asthma is a very necessary means of examination.