Maintenance of oxygenation during one-lung ventilation. Effect of intermittent reinflation of the collapsed lung with oxygen.

The aim of this study was to evaluate the effect on oxygenation of intermittent inflation with oxygen of the collapsed lung during one-lung ventilation (OLV). Sixteen patients were studied during pulmonary surgery. Balanced anesthesia with nitrous oxide and an inspired oxygen fraction of 0.5 was used. The control group (N = 8) had a median PaO2 of 19.2 (range 11.2-30.2) kPa before OLV, and 10.2 (8.2-16.0) kPa after 9 minutes of OLV without further reduction in PaO2 for another 10 minutes. In the treatment (inflation) group, the collapsed lung was manually inflated with 2 liters of oxygen and was then immediately allowed to collapse again. This procedure was repeated every 5 minutes during OLV. PaO2 increased more than 4 kPa following each inflation in seven patients. In the eighth, PaO2 remained high throughout OLV. Although PaO2 decreased between inflations, it never reached the level observed in controls during 19 minutes of OLV.