Background. This study was conducted to determine whether an alveolar recruitment
strategy (ARS) applied during two-lung ventilation (TLV) just before starting one-lung
ventilation (OLV) improves ventilatory efficiency.
Methods. Subjects were randomly allocated to two groups: (i) control group: ventilation with
tidal volume (VT) of 8 or 6 ml kg21 for TLV and OLV, respectively, and (ii) ARS group: same
ventilatory pattern with ARS consisting of 10 consecutive breaths at a plateau pressure of
40 and 20 cm H2O PEEP applied immediately before and after OLV. Volumetric capnography
and arterial blood samples were recorded 5 min (baseline) and 20 min into TLV, at 20 and
40 min during OLV, and finally 10 min after re-establishing TLV.
Results. Twenty subjects were included in each group. In all subjects, the airway
component of dead space remained constant during the study. Compared with baseline,
the alveolar dead space ratio (VDalv/VTalv) increased throughout the protocol in the
control but decreased in the ARS group. Differences in VDalv/VTalv between groups were
significant (P,0.001). Except for baseline, all PaO2 values in kPa (SD) were higher in the
ARS than in the control group (P,0.001), respectively [70 (7) and 55 (9); 33 (9) and 24
(10); 33 (8) and 22 (10); 70 (7) and 55 (10)].
Conclusions. Recruitment of both lungs before instituting OLV not only decreased alveolar
dead space but also improved arterial oxygenation and the efficiency of ventilation.
Keywords: lung, atelectasis; lung, gas exchange; surgery, thoracic; ventilation, dead space;
ventilation, one-lung ventilation