Abstract
Chronic respiratory failure is defined as the condition in which hypoxemia (PaO2≤60Torr) continues over one month. The pathogenesis and prognosis of chronic respiratory failure were studied.
The incidence of chronic respiratory failure in the past 10 years is 27.3%, and 60.4% of them are type II (PaCO2>45Torr). The death rate is 53%, which is higher than that of acute respiratory failure (24.2%). This high death rate is related to continuous hypoxemia, because no difference of death rate between type I (PoCO2≤45Torr) and II is observed, in addition mean PaO2 at exacerbation in chronic respiratory failure (43Torr) is significantly lower than in acute respiratory failure (52.3Torr). Incidence of respiratory infection and heart failure is 75% in cases of acute exacerbation, and they also are related to mortality. These factors affected the prognosis of chronic respiratory failure.
The frequently observed underlying diseases of chronic respiratory failure are pulmonary tuberculosis, chronic pulmonary emphysema, chronic bronchitis, idiopathic interstitial pneumonitis, and lung carcinoma. These diseases are complicated by different kinds and degrees of severity of multiorgan failure, furthermore, the causes of acute exacerbation and death are different in these diseases. The prognosis of chronic respiratory failure also depends on these underlying diseases.
