Abstract: The objective was to study a strategy of mechanical ventilation for patients with critically severe acute respiratory syndrome(SARS).Eight patients with critical SARS(5males and3females),aged from30to74years〔mean age(55±16)yrs〕,were enrolled in the study.After failure in routine treatment and non-invasive ventilation initiatively,all patients received tracheotomy for intermittent positive pressure ventilation.The vital sign,blood gas analysis and the oxygenation function were observed before and after ventilation.The complications and prognosis were evaluated.Results:1)All eight patients had high fever(T>38.5℃),seven showed normal white blood cell counts,and seven had dysfunction of other organs.2)The average time from onset to invasion ventilation was(27.9±12.2)d and the average time of invasion ventilation was(8.6±5.4)d.All patients used pressure controlled ventilation or pressure support ventilation plus positive expiratory end pressure(PCV/PSV+PEEP).After invasive ventilation SaO₂ increased(P<0.01).3)One patient had pneumothorax before ventilation.Bilateral pneumothorax and pneumomediastinum occurred in two patient during ventilation.4)One patient recovered after the application of mechanical ventilation.Seven patients died of severe diseases and complications.The application of mechanical ventilation in patients interminal stages of critical SARS has no obvious effect.The oxygenation and lung injury may be improved by PCV and appropriate PEEP.

Key words: severe acute respiratory syndrome(SARS), mechanical ventilation