An early test of survival in patients with the adult respiratory distress syndrome. The PaO2/FIo2 ratio and its differential response to conventional therapy. Prostaglandin E1 Study Group

Chest. 1989 Oct;96(4):849-51. doi: 10.1378/chest.96.4.849.


Patients with established adult respiratory distress syndrome (ARDS) have a mortality rate that exceeds 50 percent. We analyzed the magnitude of hypoxemia as manifest by the PaO2/FIO2 ratio and its early response to conventional therapy including positive end-expiratory pressure (PEEP) in the placebo group of a large multicenter study. The PaO2/FIO2 ratio was not different at the time of diagnosis of ARDS in those patients who lived compared to those who subsequently died. After one day of conventional therapy including PEEP, those patients who survived increased their PaO2/FIO2 ratio. The nonsurvivors did not improve over a seven-day course. The difference in the PaO2/FIO2 ratio was significant throughout the seven-day observation period. We conclude that the early response to conventional therapy picks a patient population with a good prognosis and can be used as a test of likely survival from ARDS.

Publication types

  • Clinical Trial
  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Alprostadil / therapeutic use
  • Female
  • Humans
  • Hypoxia / therapy
  • Male
  • Middle Aged
  • Multicenter Studies as Topic
  • Placebos
  • Positive-Pressure Respiration
  • Prognosis
  • Randomized Controlled Trials as Topic
  • Respiratory Distress Syndrome / mortality*
  • Respiratory Distress Syndrome / therapy
  • Retrospective Studies


  • Placebos
  • Alprostadil