Abstract: The objective was to discuss the characteristics of metabolism of oxygen and its correlation with clinical manifestations in Severe Acute Respiratory Syndrome.Retrospective study was designed.Blood gas in 88 patients was detected up to 213 times.It was found that the decrease of PaO₂ was the most common(85.0%,181/213),the decrease of SaO₂ is the second(68.1%,145/213),and the increase of PaCO₂ is the least common(5.6%,12/213).All the data indicated that the incidence of hypoxemia was the most prevalent and the increase of carbon dioxide was the least in all these patients.Hy-poxemia,clinical typing and phase were correlated,and respiratory alkalosis was widespread.In patients who died of SARS,there were not only respiratory alkalosis but also compound disorder of blood gas.The variation of metabolism of oxygen is the decrease of PaO₂ in the initial stage and overventilation excited by hypoxemia.At the same time the decrease of PaCO₂ causes respiratory alkalosis,and the development of compound disorder of blood gas.Correlation exists between hypoxemia,clinical condition and prognosis,indicating that the treatment of oxygen in the initial stage is important.

Key words: atypical pneumonia, SARS, blood gas analysis, hypoxemia *Beijing Chaoyang Hospital, Affiliate of Capital University of Medical Sciences