Cardiorespiratory effects of pressure controlled inverse ratio ventilation in severe respiratory failure

Chest. 1989 Dec;96(6):1356-9. doi: 10.1378/chest.96.6.1356.


Cardiorespiratory values were measured in nine patients with severe respiratory failure before and following initiation of pressure controlled inverse ratio ventilation (PC-IRV) at an inspiratory to expiratory ratio of 2:1. All patients showed increases in PaO2, with the mean PaO2 rising from 63 +/- 4 (mean +/- SEM) to 76 +/- 8 mm Hg. Peak inspiratory pressure fell from 44 +/- 4 to 39 +/- 2 cm H2O. There were no significant changes in any hemodynamic or oxygen metabolism variable associated with the institution of PC-IRV. In particular, no significant alteration in cardiac index, pulmonary artery pressures, oxygen delivery, oxygen consumption, or oxygen extraction ratio occurred with the use of PC-IRV. These results suggest that PC-IRV may be a useful ventilatory modality in the treatment of severe respiratory failure since it results in improvement in arterial oxygenation without any deterioration in hemodynamic or tissue oxygen metabolism parameters.

MeSH terms

  • Adult
  • Aged
  • Female
  • Hemodynamics*
  • Humans
  • Male
  • Middle Aged
  • Oxygen / blood
  • Prospective Studies
  • Pulmonary Artery / physiopathology
  • Respiration, Artificial / methods*
  • Respiratory Distress Syndrome / therapy*
  • Respiratory Function Tests
  • Vascular Resistance


  • Oxygen