Effects of a preemptive alveolar recruitment strategy on arterial oxygenation during one-lung ventilation with different tidal volumes in patients with normal pulmonary function test

Abstract

Background: Hypoxemia during one-lung ventilation (OLV) remains a major concern. The present study compared the effect of alveolar recruitment strategy (ARS) on arterial oxygenation during OLV at varying tidal volumes (Vt) with or without positive end-expiratory pressure (PEEP).

Methods: In total, 120 patients undergoing wedge resection by video assisted thoracostomy were randomized into four groups comprising 30 patients each: those administered a 10 ml/kg tidal volume with or without preemptive ARS (Group H and Group H-ARS, respectively) and those administered a 6 ml/kg tidal volume and a 8 cmH2O PEEP with or without preemptive ARS (Group L and Group L-ARS, respectively). ARS was performed using pressure-controlled ventilation with a 40 cmH2O plateau airway pressure and a 15 cmH2O PEEP for at least 10 breaths until OLV began.

Results: Preemptive ARS significantly improved the PaO2/FiO2 ratio compared to the groups that did not receive ARS (P < 0.05). The H-ARS group showed a highest PaO2/FiO2 ratio during OLV, the L-ARS and H groups showed similarly improved arterial oxygenation, which was significantly higher than in group L (P < 0.05). The plateau airway pressure in group H-ARS was significantly higher than in group L-ARS (P < 0.05).

Conclusions: Preemptive ARS can improve arterial oxygenation during OLV. Furthermore, a 6 ml/kg tidal volume combined with 8 cmH2O PEEP after preemptive ARS may reduce the risk of pulmonary injury caused by high tidal volume during one-lung ventilation in patients with normal pulmonary function.

Keywords: Alveolar recruitment; One-lung ventilation; Oxygenation; PEEP; Preemptive; Tidal volume.

Fig. 1

The ratio of partial pressure of arterial oxygen and fraction of inspired oxygen (PaO₂/FiO₂ ratio). Values are expressed as mean ± SD. Group H received OLV at a 10 ml/kg tidal volume (n = 30), group H-ARS received OLV at a 10 ml/kg tidal volume after applying preemptive ARS during TLV (n = 30), group L received OLV at a 6 ml/kg tidal volume with a 8 cmH₂O PEEP (n = 30), and group L-ARS received OLV at a 6 ml/kg tidal volume with a 8 cmH₂O PEEP after applying pre-emptive ARS during TLV (n = 30). Tb: During TLV Before starting ARS, T5: 5 min after OLV, T15: 15 min after OLV, T30: 30 min after OLV, T45: 45 min after OLV. ARS: alveolar recruitment strategy, Vt: tidal volume, OLV: one-lung ventilation. ^*P < 0.05 is compared with Group L, ^†P < 0.05 is compared with Group L-ARS.

Fig. 2

The changes of the peak airway pressure (A), the plateau airway pressure (B), and the static compliance (C). Values are expressed as mean ± SD. Group H received OLV at a 10 ml/kg tidal volume (n = 30), group H-ARS received OLV at a 10 ml/kg tidal volume after applying preemptive ARS during TLV (n = 30), group L received OLV at a 6 ml/kg tidal volume with a 8 cmH₂O PEEP (n = 30), and group L-ARS received OLV at a 6 ml/kg tidal volume with a 8 cmH₂O PEEP after applying pre-emptive ARS during TLV (n = 30). Tb: During TLV Before starting ARS, T-ARS: Just before OLV with or without ARS, T5: 5 min after OLV, T15: 15 min after OLV, T30: 30 min after OLV, T45: 45 min after OLV. ARS: alveolar recruitment strategy, Vt: tidal volume, OLV: one-lung ventilation. ^*P < 0.05 is compared with Group L, ^†P < 0.05 is compared with Group L-ARS.