Both lung recruitment maneuver and PEEP are needed to increase oxygenation and lung volume after cardiac surgery

Acta Anaesthesiol Scand. 2004 Feb;48(2):187-97. doi: 10.1111/j.0001-5172.2004.00300.x.


Background: Patients ventilated after cardiac surgery commonly have impaired oxygenation, mainly due to lung collapse. We have previously found that PaO2 and end-expiratory lung volume (EELV) were increased by a lung recruitment maneuver (LRM) followed by positive end-expiratory pressure (PEEP). The aim of this study was to evaluate whether only PEEP or only a LRM could give similar effects.

Methods: Thirty circulatory stable patients (aged 55-79 years) mechanically ventilated after cardiac surgery were randomized to receive LRM (four 10-s insufflations to an airway pressure of 45 cmH2O) and zero end-expiratory pressure (LRM-group), PEEP 12 cmH2O (PEEP-group) or LRM in combination with PEEP 12 cmH2O (LRM + PEEP-group). The set end-expiratory pressure was kept for 75 min. Before, during and after the intervention, EELV (SF6 washout technique) and blood gases were measured.

Results: Initial EELV and PaO2 were similar in all groups. In the LRM-group, PaO2 and EELV increased transiently (P < 0.0001), but returned at 5 min to the initial values. In the PEEP-group, PaO2 did not change but EELV increased to 155 +/- 27% of the initial value (P < 0.0001). In the LRM+PEEP-group, PaO2 and EELV increased to 212 +/- 66% and 178 +/- 31% of the initial values (P < 0.0001), respectively, and were maintained during PEEP application.

Conclusion: In patients ventilated after cardiac surgery: (1) PEEP increased lung volume but not PaO2, (2) a lung recruitment maneuver without subsequent PEEP had no sustained effect, and (3) both a lung recruitment maneuver and PEEP were needed to increase and maintain the increased lung volume and PaO2.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Aged
  • Blood Pressure
  • Carbon Dioxide / blood
  • Cardiac Surgical Procedures*
  • Female
  • Humans
  • Lung Compliance
  • Lung Volume Measurements
  • Male
  • Middle Aged
  • Oxygen / blood*
  • Positive-Pressure Respiration*
  • Radiography, Thoracic


  • Carbon Dioxide
  • Oxygen