Dramatic effect on oxygenation in patients with severe acute lung insufficiency treated in the prone position

Crit Care Med. 1997 Sep;25(9):1539-44. doi: 10.1097/00003246-199709000-00022.


Objective: To confirm the positive effect of prone positioning on oxygenation in patients with acute lung insufficiency.

Design: Clinical follow-up study.

Setting: The intensive care unit at a tertiary care academic hospital.

Patients: Thirteen patients suffering from severe acute lung insufficiency caused by trauma, septicemia, aspiration, and burn injury. Eleven of the patients had severe hypoxia (oxygenation indices [PaO2/FIO2] < or = 80 torr [< or = 10.7 kPa]). Patients > 70 yrs of age were excluded from the study.

Interventions: Treatment in the prone position without changing other ventilatory settings than FIO2 when saturation increased.

Measurements and main results: Twelve of the 13 patients responded to treatment in the prone position. The patient that did not respond improved her gas exchange when nitric oxide was instituted. She died, however, from a Gram-negative septicemia. No patient needed extracorporeal membrane oxygenation. Apart from the settings of FIO2 when saturation increased, the ventilatory settings were unchanged. In the prone position, the oxygenation index increased (p < .0002) and the alveolar-arterial oxygen gradient, P(A-a)O2, decreased dramatically (p < .0001).

Conclusions: The prone position significantly improves impaired gas exchange due to severe acute lung insufficiency. It is suggested that this treatment is used before more complex modalities.

MeSH terms

  • Acute Disease
  • Adult
  • Aged
  • Critical Care
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Middle Aged
  • Oxygen / blood
  • Oxygen Consumption*
  • Prone Position*
  • Pulmonary Gas Exchange*
  • Respiratory Insufficiency / metabolism*
  • Respiratory Insufficiency / physiopathology
  • Respiratory Insufficiency / therapy*
  • Supine Position
  • Survival Analysis
  • Time Factors


  • Oxygen